Đánh giá khả năng phối hợp của một số dòng ngô địa phương

7/24/2019 nh gi kh nng phi hp ca mt s dng ng a phng

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B gio dc v o totrng i hc nng nghip i

---------------------------

lu b hng

nh gi kh nng phi hpca mt s dng ng a phng

Lun vn thc s nng nghip

Chuyn ngnh : trng trt

M s : 60.62.01

Ngi hng dn khoa hc: TS. v vn lit

H ni - 2005


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Li cam oan

- Ti xin cam oan rng, s liu v kt qu nghin cu trong lun vn l

trung thc v cha tng c s dng bo v mt hc v no.

- Ti xin cam oan rng, mi s gip cho vic thc hin lun vn

ny c cm n v cc thng tin trch dn trong lun vn ny c ch

r ngun gc

Tc gi lun vn

Lu B Hng


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Li cm n

Tc gi lun vn xin by t lng bit n su sc ti:

- TS. V Vn Lit, ngi hng dn khoa hc trc tip ng gp

nhiu kin quan trng t nhng bc nghin cu ban u v c trong qu

trnh thc hin vit lun vn.

- Tp th cc thy c gio Khoa Nng hc, c bit cc thy c trong

b mn Di truyn - Ging Trng i hc Nng nghip I H Ni trc

tip ng gp nhiu kin qu bu cho tc gi hon thnh lun vn ny.

- Cm n cc nh Khoa hc trong ngnh, cc ng nghip, bn b v

ngi thn ng vin gip ti trong qu trnh cng tc v hc tp.

Tc gi lun vn

Lu B Hng


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Mc lc

Li cam oan i

Li cm n iiMc lc iii

Danh mc cc ch vit tt v

Danh mc cc bng vi

1. M u 1

1.1. Tnh cp thit ca ti 1

1.2. Mc ch, yu cu, ngha khoa hc v thc tin 3

2. Tng quan ti liu 5

2.1. C s khoa hc ca ti 5

2.2. Yu cu iu kin ngoi cnh ca cy ng 7

2.3. Kh nng chng chu iu kin bt thun ca cy ng 8

2.4. Chn to ging ng 8

2.5. Tnh hnh sn xut v s dng ng trn th gii v trong nc 29

3. Ni dung v phng php nghin cu 39

3.1. Ni dung nghin cu 39

3.2. Phng php nghin cu 39

3.3. Phng php thu thp v x l s liu 46

4. Kt qu nghin cu v tho lun 47

A.Th nghim 1 47

4.1. c im sinh trng ca cc THL 47

4.1.1. Cc giai on sinh trng ca cc THL 474.1.2. Tc tng trng chiu cao cy 52

4.1.3. Tc tng trng s l 55

4.1.4. Chiu cao cui cng v chiu cao ng bp 57

4.2. Cc yu t cu thnh nng sut v nng sut 60

4.2.1. Cc yu t cu thnh nng sut 60

4.2.2. Nng sut ca cc THL 63


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4.3. Hnh thi bp 66

4.3.1. Chiu di bp 66

4.3.2. Chiu di ui chut. 664.3.3. ng knh bp 69

4.3.4. ng knh li v su cy. 69

4.4. Mt s c tnh chng chu ca cc THL 70

4.4.1. Kh nng chng chu vi mt s loi su bnh hi chnh : 72

4.4.2. c tnh chng , gy 73

4.5. Kh nng kt hp v nng sut ca cc THL 73

B. Th nghim 2 804.6. c im sinh trng v pht trin ca cc THL 80

4.6.1. Giai on t gieo n mc 80

4.6.2. Thi gian t gieo n tr c 82

4.6.3. Thi gian t gieo n tung phn, phun ru 82

4.6.4. Chnh lch gia thi gian tung phn v phun ru 82

4.6.5. Thi k chn sinh l 82

4.7. Mt s c tnh sinh trng 834.7.1. ng thi tng trng chiu cao cy 83

4.7.2. ng thi tng trng s l 84

4.7.3. Chiu cao cy cui cng 86

4.7.4. Chiu cao ng bp (cm) 86

4.8. Cc yu t cu thnh nng sut v nng sut 88

4.9. Hnh thi bp 90

4.10. Mt s c tnh chng chu ca cc t hp lai 94

4.10.1. c tnh chng chu su bnh 94

4.10.2. c tnh chng gy ca cc ging ng th nghim 96

4.11. Kh nng kt hp ca cc t hp lai th nghim 96

5. Kt lun v ngh 100

Ti liu tham kho 101


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Danh mc cc ch vit tt

CT : Cng thc

STT : S th t

KNKH : Kh nng kt hp

KNKHC : Kh nng kt hp chung

KNKHR : Kh nng kt hp ring

NN : Nng nghip

THL : T hp lai


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Danh mc cc bng

Bng 2.1. Din tch, nng sut v sn lng ng trn th gii giai on t1998 2000 32

Bng 2.2. Bng sn lng ng ca mt s nc sn xut ng ln trn th

gii (2003) 34

Bng 2.3. T l s dng ng lai mt s nc (theo CIMMYT 2000-2003) 34

Bng 2.4: Din tch, nng sut, sn lng ng Vit Nam giai on 1999-2003 35

Bng 4.1a: Cc giai on sinh trng ca cc THL 48

Bng 4.1a.1. Vi cy th Khulo 48

Bng 4.1a.2 Vi cy th Pucru 49

Bng 4.2a : Tc tng trng chiu cao cy ca cc THL 53

Bng 4.2a.1 Vi cy th Khulo 53


Bng 4.3a: Tc tng trng s l ca cc THL 56

Bng 4.3a.1 Vi cy th Khulo 56Bng 4.3a.2 Vi cy th Pucru 56

Bng 4.4a: Mt s ch tiu hnh thi ca cc THL 57



Bng 4.6a : Mt s ch tiu cu thnh nng sut v nng sut ca cc t

hp lai 61

Bng 4.6a.1 Vi cy th Khulo 61Bng 4.6a.2 Vi cy th Pucru 62

Bng 4.8a: Nng sut ca cc THL 64



Bng 4.7a: Hnh thi bp ca cc THL 67



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Bng 4.5a: c tnh chng chu mt s loi su bnh chnh v gy

ca cc THL. 70Bng 4.5a.1 Vi cy th Khulo 70


Bng 4.9a : Bng phn tch phng sai I 74

Bng 4.9a.1 Cc THL t 1 n 32 74

Bng 4.9a.2: Cc THL t 32 n 64 74

Bng 4.10a. Bng phn tch phng sai II 75

Bng 4.10a.1. Cc THL t 1 n 32 75

Bng 4.10a.2. Cc THL t 32 n 64 75

Bng 4.11a. Gi tr KNKH chung v nng sut 76

Bng 4.11a.1. Cc THL t 1 n 32 76

Bng 4.11a.2. Cc THL t 32 n 64 77

Bng 4.12a. Gi tr KNKH ring v nng sut 78

Bng 4.12a.1. Cc THL t 1 n 32 78

Bng 4.12a.2. Cc THL t 32 n 64 79

Bng 4.1b: Thi gian sinh trng v pht trin ca cc THL 81

Bng 4.2b: Tc tng trng chiu cao cy ca cc THL 83

Bng 4.3b: Tc tng trng s l ca cc THL 85

Bng 4.4b: Chiu cao cui cng, chiu cao ng bp ca cc THL 87

Bng 4.6b: Cc yu t cu thnh nng sut ca cc THL 89

Bng 4.7b: Hnh thi bp ca cc THL 91Bng 4.8b: Nng sut l thuyt v nng sut thc thu ca cc THL 93

Bng 4.5b: c tnh chng chu su bnh v gy ca cc THL 95

Bng 4.10b : Bng phn tch phng sai I 96

Bng 4.11b. Bng phn tch phng sai II 97

Bng 4.12b. Gi tr KNKH chung v nng sut 97

Bng 4.13b. Gi tr KNKH ring v nng sut 98


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1. M u

1.1. Tnh cp thit ca ti

Cy ng l mt trong ba cy ng cc quan trng cung cp lng thc

cho loi ngi, n nui sng 1/3 s dn trn th gii, tt c cc nc trng ng

ni chung u n ng mc khc nhau. Ton th gii s dng 21% sn

lng ng lm lng thc cho ngi. Cc nc Trung M, Nam v chu

Phi s dng ng lm lng thc chnh. Gn y cy ng cn c s dnglm thc phm vi bp ng bao t lm rau sch cao cp. Sn phm ca cy

ng l ngun nguyn liu khng th thiu cho nghnh chn nui vi thc n

tinh, thc n chua, cho cc nghnh cng nghip lng thc - thc phm -

dc phm, cng nghip nh, l mt hng nng sn xut khu c gi tr cao.

Hin nay din tch trng ng ton th gii c tnh khong 140 triu ha,

nng sut bnh qun khong 44 t/ha v sn lng khong hn 600 triu tn

(CIMMYT- 2000). Nhu cu v ng cn rt ln. Mun p ng c nhu cu

ch c th bng 2 bin php : mt l m rng din tch trng, hai l p dng

nhng bin php k thut tin tin tng nng sut, sn lng ng v trong

bin php th hai c tnh quyt nh.

Vo nhng thp nin cui ca th k XX, cng vi cy u tng v

cy bng, cy ng c nhng sn phm bin i gen vi nng sut vt tri.

Bn cnh nh ng dng rng ri cng ngh u th lai, k thut nng hctin tin v nhng thnh tu khc trong cng ngh sinh hc, cng ngh bo

qun, ch bin ngh trng ng trn th gii c nhng bc pht trin t

ph.

Vit Nam, ng l cy lng thc ng th hai sau la, n c trng

trn nhiu vng sinh thi vi nhiu thi v khc nhau, c bit trong nhng


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iu kin bt thun, n c coi l cy mu chnh trong sn xut nng nghip.

Nhng do sn xut nng nghip nc ta cn lc hu v vy nng sut, sn

lng ng hin nay cn thp, hng nm chng ta vn phi nhp mt lng ngln.

Theo k hoch ca B Nng nghip v Pht trin nng thn, n nm

2005 din tch trng ng trn c nc phi t 1 triu ha, sn lng t

khong 4 - 5 triu tn. D bo ti nm 2010 Vit Nam cn t 5 n 6 triu tn

ng phc v cho nhu cu thc n gia sc v lm lng thc (theo Trn

Hng Uy 2002[20]. p ng y c v s lng v cht lng cho nhu

cu ng nc ta hin nay v trong tng lai th ngoi vic t chc sn xut,

hon thin quy trnh k thut cho cy ng i hi phi c c b ging ng

tt: nng sut cao, phm cht tt, kh nng thch ng rng. Chnh v vy cng

tc ging l v cng quan trng, mt trong nhng phng php u vit vn

c s dng trong cng tc ging l phng php to u th lai.

Cy ng l mt trong nhng cy trng u tin c con ngi ng

dng u th lai trong chn to ging. Nm 1877, mt nh khoa hc M l Bill p dng u tin hin tng u th lai vo vic to ra cc ging ng lai. Kt

qu ng thu c cc cp lai hn hn cc ging b m v nng sut t 10 -

15%, kt qu ny chng minh s tn ti v tm quan trng ca u th lai.

Cc nh khoa hc tnh rng cc ging ng lai ng gp 60% v k thut

canh tc ng gp 40% vo mc tng trng nng sut. Vit Nam, t l s

dng ging ng lai tng rt nhanh trong nhng nm gn y. Nm 1990 btu trng ng lai (0%) nm 1995 c 30% din tch trng ng lai, nm 1999 l

60% v nm 2001 t 65%, d kin nm 2005 t 90%.

Trong qu trnh chn to ging u th lai, vic xc nh cp lai c u

th lai cao l vn ct li. Do xc xut thnh cng trong lai to ging rt

thp nn nng cao hiu qu ca qu trnh ny phi s dng nhng dng b

m c kh nng kt hp cao.


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Trn c s nhng l do nu trn m chng ti tin hnh thc hin ti :

"nh gi kh nng phi hp ca mt s dng ng a phng".

1.2. Mc ch, yu cu, ngha khoa hc v thc tin1.2.1. Mc ch

nh gi KNKH ca cc dng, chn ra cc dng c KNKH cao phc

v cho cng tc to ging lai tng hp.

1.2.2. Yu cu

Theo di v nh gi mt s ch tiu v s sinh trng, pht trin, cc

yu t cu thnh nng sut v nng sut, kh nng chng chu vi su bnh vcc iu kin bt thun.

1.2.3. ngha khoa hc

Thnh cng trong qu trnh chn to ging ng lai ni ring v cng

nhchn ging cy trng ni chung ph thuc rt nhiu vo ngun vt liu

khi u v qu trnh th kh nng kt hp ca cc dng thun. Do vy cng

tc thu thp v nh gi vt liu l ht sc quan trng. nh gi kh nng kthp ca cc dng, ging ng thc cht l xc nh u th lai. u th lai li

chu s chi phi mnh m bi s khc bit di truyn gia hai dng b m. Vt

liu to ging ch c gi tr khi chng c xc nh l c kh nng kt hp

cao v c nhiu tnh trng di truyn c li cho con ngi.

1.2.4. ngha thc tin

Ging ng ci tin v ging ng lai cha ph hp vi iu kin canh tcnh nc tri v kinh t a phng vng min ni v:

- Vng ni t c dc cao, mu m thp nhiu ni khng c nc tc.

- Vng ni hu ht l ng bo dn tc, i sng cn ngho, kh nng u t

k thut, phn bn thuc tr su, thuc bo v thc vt rt thp.

- Ngi dn tc t ngi c nhu cu tiu dng ng lm lng thc.


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Chnh t nhng l do trn m vic to ging ng lai tng hp t cc

ging ng a phng nhm nng cao nng sut nhng li tn dng c

ngun gen qu l:- kh nng thch ng cao vi iu kin kh khn.

- ph hp vi tp qun canh tc v tiu dng.


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2. Tng quan ti liu

2.1. C s khoa hc ca ti

Mt sbng chng chra rngng c thun ha tloi cmexican

hoang di teosinte (Zea mays ssp. Parviglumis hoc ssp mexicana). Nhng

bng chng kho c hc chng minh rng thi gian thun ha ng vo

khong 5000 n 10.000 nm trc y, mc d ngun gc gn y ca ng

c xc nh tteosinte, nhng cy ny khc bit su sc vhnh thi. Mt

imkhc bit chyu l teosinte inhnh c nhnh cdi trn nh bng

c trong khi ng c nhnh nh cngn bng bp. Phn tch di truyn nhn

thy rng teosinte branched 1(tb1) nhl mt gen tng hp rng iu khin

skhc bit ny [46]

Trong cc cy trng ly ht ch yu trn tri t, ng l cy c tim

nng nng sut cao nht. Nng sut ng Mt 23 tn/ha. Ng l cy trng

ph bin rng ln n c th trng trong nhiu iu kin mi trng khc

nhau, sn phmc sdng lm lng thc cho ngi, thc n gia sc v

cho cng nghip [41].Nhng nm 1940 Anderson and Cutler nhn thy

mc quan trng ca a dng di truyn ng v xc nh cc loi nh l

mt nhm bao gm nhng c th c nhng c im chung coi nh l mt

nhm. Cc c im hnh thi phn nh miquan hdi truyn v c s

dng phn loi loi ng Mexico, Trung M, Nam Mv Hoa K. Cs

ny c chngminh thm bngdi truyn phn t. Hin nay c 42 loi v

M rt nhiu ging ng th phn tdo u thc trng trc khi c cc

ging ng u thlai v chng cung cp ngun gen to ging ng u th

lai hin nay v hu ht cc khu vc trn th gii. ng tic l hu ht cc

ging ng thphntdo vng Bc M bmt[34]


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To ging cy giao phn bao gm hai hng chnh l to ging th

phntdo v to ging u thlai. To ging thphn tdo bng cc phng

php chn lc ci tin qun th c thc hin trt sm da trn cskhoa hc thay i tn sut gen v kiu gen qua cc chu k chn lc. Theo

Walter R. Fehr, (1983) chn lc trc thphn hiu quthay itn xut gen

v kiugen gp 2 ln chn lc sau thphn.V d: Tn sut gen ca qun th

ban u 0,40RR + 0,32 Rr + 0,64 rr tn xut gen R = 0,2 vr = 0,8 nu chn

lc trc thphn qun thmi c tn sut kiugen l 0,31 RR + 0,50 Rr +

0,19rr, tn sut gen l 0,56R v 0,44r. Nhng chn lc sau thphn qun thmi c tn sut kiugen l 0,11 RR + 0,54Rr + 0,35 rr v tn sut gen l R =

0,38 v r = 0,62.

Tn sut gen ca qun thngun(Co) v qun th sau chn lc (C1)

nhsau:

Tn sut genQun th

R rQun thngun (C0) 0,20 0,80

Qun thsau chn lc (C1) chn lc sau khi thphn 0,38 0,62

Qun thsau chn lc (C1) chn lc trc khi thphn 0,56 0,44

y l nguyn l rt quan trng ng dng trong cc phng php chn

lc chu k. Chn lc sau th phn c xem l ch chn cy m, chn lc

trc thphn l c th chn lc c chai bm. Chn lc cy giao

phn c thphn chia thnh cc phng php khc nhau nh chn lc hn

hp, hn hp ci tin, bp trn hng v chn lc chu k. Tuy nhin phn chia

nhvy chl tng i v tt ccc phng php u c thcoi l chn lc

chu k[50].


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Mt s lng ln khi lai cc dng hoc cc ging khc nhau v di

truyn cho sc sngu thlai v u thlai thhF1. Con lai F1 c sc

sng v nng sut cao hn bm ca chng. Hin tngny c khaithc nhn c nng sut cao hn trong sn xut thng mi, c bit vi

cc cy thphn cho vic duy tr sng nht v n nh kh khn. u th

lai c thcoi l trng thi dhp ti a v nhn c dhp ti a ny khi lai

gia hai dng tphi khc nhau. Pht trin v sdng u thlai kh phc tp

v tri qua cc giai on nhsau :

1) La chn vt liu cho dng tphi2) Pht trindng tphi

3) Thkhnng phi hp

4)Nghin cu nhn dng tphiv sn xut ht lai [44]

u thlai khng phi l mt kt qubt bin khi lai giahai dng t

phi bi v cc dng tphi c thging nhau vdi truyn, gi trdng t

phi c nh gi trn csmc u thlai nhn c khi thp vi mtdng khc. Davis (1927) xut thkhnng phi hp chung l dng mt

tester chung th vi cc dng t phi. Tester c th l mt ging, mt

ging lai nhng phi c nhiu tnh trng tt v csdi truyn rng [45]

Cc dng tphi cho nng sut cao vi Tester sc chn v tester

bi, Mt s lng ln dng tphi c nh gi c khnng phi hp

c gili thc hin lai diallel l thkhnng phi hp ring [47]

2.2. Yu cu iu kin ngoi cnh ca cy ng

Ng l cy c khnng thch nghi rng vi iu kin mi trng v

c trng nhiu iu kin sinh thi. Nhn chung ng ph hp vi nhit

trung bnh 68 n 72oF (20 27oC). t tt v thot nc, lng ma t500

n 1100mm trong giai on sinh trng pht trin ca ng. Ng c nhu cu


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nc v m mc cao hn so vi cc cy ly ht khc, n mn cm vi mi

trng giai on trctung phn v phun ru. Mc d c mt sging chu

hn nhng hu ht cc ging bhn thi ktrcphun ru sgim nng sut[40]

2.3. Kh nng chng chu iu kin bt thun ca cy ng

Nhng iu kin bt thun i vi thc vt l nhng iu kin ngoi

cnh c nh hng xu n sinh trng, pht trin v nng sut thc vt hc

ca cy trng. iu kin bt thun sinh hc v phi sinh hc c thlm gimti 65 87 % nng sut cy trng ty theo loi cy [28]

Bt thun sinh hc bao gm cc loi sinh vt khc gy nh hng xu

n cy nhsu bnh, cdi. Nhng bt thun phi sinh hc bao gm nhng

hin tng kh hu cc oan vnhit (nng, lnh) vnc (hn, ng, gi)

v dinh dng nh mt cn bng dinh dng (P, Zn, Mn, Mg) nhim c

mui (t mn), c nhm (t phn) c st, kim loi nng [43]Cy ng thuc loicy C4, cn 350 n 500 lt nc sn sinh ra 1 kg

ht (tutheo kh hu v tnhtrng dinh dng t), nng sut ng c tht

12 15 tn/ha ddng trong iu kin c ti [27]

Khi bhn tlr/thn l ng tng, khi hn tng tlny cng gim

v gim mnh tc hp thdinh dng tt. Khi hn, xy ra sphn b

li cht dinh dng trong thn, nu hn xy ra trng vi thi ktch ly cht

kh vo ht dn n ng bchn p, ht lp, cy non. Hn xy ra thi k

cy con nh hng n mt , gim din tch l v tc quang hp [26]

2.4. Chn to ging ng

Cy ng (Zea mays L.) Protein c xem l cht lng thp bi v hm

lnghai axit amin l lysine v triptophan mc thp. gii quyt vn


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ny ngi ta s dng gen opaque-2 ci thin hm lng amino axit

nhng c hiu qutri ngc vi mt sc imnng hc. Mt chng

trnh chn lc chu kkiuhnh vi qun thng non-opaque ci tin chtlng protein khng sdng gen. Qua 4 chu k v 20% chn lc vi hm

lngtripthan trong ht nh gi qua 3 a phng cc c imnng hc.

Hm lng triptophan v protein thnghim ring rc thc hin bi v

cc cy cc c thphn bng tay. Qun thIG2 khng tng hm lng

triptophan trong khi qun thIG1 tng nhl 0,70%/ mt chu kchn lc. T

ltriptophan/protein tng1,26% /mt chu kchn lcv nng sut tng 2,5%mt chu kv c tng quan cht vi chn lc [31]

Cc loi ging ng lai: Gingng lai c th to ra l ng lai quy c

(Trn cscc dng tphi thun) v lai khng quy c(c t nht mt b

mkhng phi l dng tphi thun) (Vasal,1988). Lai quy c gm lai n,

lai ba v lai kp, lai n trn cshai dngbmtphi, lai ba l lai gia

mt lai n v mt dng t phi, lai kp l lai gia hai lai n. Lai nthng c pht trin nhiu trn thgii v n cho nng sut cao v ng

u nhng n rt kh nhn dng bmv sn xut ht lai. Lai khng quy c

c phn lm 4 loi chnh l :

Lai giacc ging

Lai gia cc gia nh

Lai nh

Lai nh kp (Vasal and Gonzalez, 1999a)

Hu ht cc ging ng lai khng quy c trn cs2 thp. Ging lai

khng quy c thc cht l lai gia cc ging trn cslai gia 2 ging, 2

qun th. Lai giacc gia nh l laigia 2 gia nh full sib hay half- sib to


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ra t cc qun thging nhau hoc khc nhau. u thlai nh kp gm mt

lai n vi mt ging, mt qun thhoc mt gia nh. Lai khng quy c

mc ng u v nng sut thp hn lai quy c [26]

Ht bmtphi l nntng sn xut ht ging ng lai quy c v

mt sdng ging ng lai khng quy c. Pht trin cc dng tphi tt l

rt quan trng nhng l mt qu trnh kh v tn km. Theo Hallauer v

Miranda,1997, khong 10.000 dng S2 hoc S3 test cui cng ch1dng c

sdng trong ging lai thng mi. Nhiu nguyn nhn ca nhng kh khn

v chi ph cao gm :

a) Gim sc sng v nhng biuhin tnh trng c hi lm cc dng t

phi khng thsdng c.

b) Cng vic nh gi khnng phi hp chi ph cao, khi lng cng

vic ln.

c) Thc cht cc dng tphi ngoi khnng thp c nng sut caocn phi c nhiu tnh trng khc c bit trong sn xut ht lai n.

So vi ging ng dng tphi thp hn, sc sng km, thn mnh, ru

v bp nh, nng sut thp hn. Bn cnh c chng thng mn cm hn vi

iu kin bt thun v su bnh v ni chung chng qu mn cm vi iu

kin bt thun to ra vn ln trong sn xut ht [32]

Dodd (1998) tho lun v im ni bt ca xu hng lai cng gingtrong sn xut ht ging ng u thlai qua 10 nm v lin kt vn ny

vi thiu phn ca cc dng b. ng ch ra rng s thiu phn l mt xu

hngkhng trnh khi khi chng ta ynng sut ht ln cao, s c cnh

tranh gia ht v phn. Mc d vy gi ca ng rng ngoi ch n sn

xut dng m cng rt cn quan tm n sn xut dng b, cc dng bc


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phn tt cho php tng shng mv thng t gp kh khn trong trtrng

khp.

Cc phng php nh gi khnng to phn bao gm :

a) Phng php ca Wych, pers. comm.(1998), ly v cn 15 mu c

trc khi tung phn v sau khi tung phn, skhc nhau vkhi lng l mt

chtiu nh gi khnng to phn ca dng b.

b) Bao cch ly 10 bao c trn dng bv thu phn hng ngy (5-10

ngy) phn thu c o trong ng ong v kimtra sc sng bng knh hin

vi.

c) nh du cy khi bt u tung phn, hng ngy rung phn ca cc

cy vo t giy em so snh vi lng phn ca mt ging tiu

chun(Thielen,1986). Ngoi ra dng bcn phi c c iml c chiu cao

cy thch hp v n nh [39]

2.4.1. Khi nim dng thun v phng php to dng thun.

2.4.1.1. Khi nim dng thun

Dng thun l khi nim tng i ch cc dng t phi t ti

ng u v n nh cao nhiu tnh trng, i vi ng thng sau 7 9 i

t phi dng t ti ng u cao cc tnh trng nh: cao cy, cao ng

bp, nng sut, dng v mu sc ht v.v.... v c gi l dng thun. Nh

vy dng thun l dng c kiu gen ng hp t vi t l cao nhiu ctrng di truyn. Ngun vt liu to dng thun gm cc ging ng a

phng, cc ging ng th phn t do, ging ci tin v cc ging ng

lai.v.v....(B. Brown, 1953)[39]. (E.E.G. Gama v A.R.Halauer 1977)[35]

2.4.1.2. Phng php to dng thun

To dng thun l mt phn quan trng ca chng trnh to ging ng


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lai. Cho n nay, cc nh khoa hc xut v s dng mt s phng php

nhsau:

+ Phng php chun (Standard method).

y l phng php ch yu c p dng rng ri nht trn th gii

l t phi cng bc lin tc qua 7 9 i. T phi nhm t c ng

hp t vi t l ngy cng cao nhiu tnh trng (trch dn theo Nguyn Hu

Phc, 2002)[12].

+ Phng php Sib (cn phi) hoc Fullsib (cn phi gia anh em ng

mu).

Nm 1974 Stringfield b sung phng php to dng rng cn gi l

phng php to dng fullsib nhm gim mc suy thoi do t phi gy nn

(ko di thi gian chn lc dng). Tuy nhin, phng php sib hoc fullsib c

cng t phi km, qu trnh t n ng hp t chm hn v c h s

bin d ln hn (trch dn theo Nguyn Hu Phc, 2002) [12]

+ Phng php hn hp (Bulk method).

Phng php ny c mt s nh chn to ging s dng (R. J.

Saikumar, 1999). Theo phng php ny, t cc bp trong mt i t phi

c hn hp li c gieo thnh hng v sau tin hnh t th nhng cy

c chn. C tip tc tin hnh nhvy trong 3 5 v cho n khi dng t

ng hp t cao. Sau mi bp t phi c ring v gieo thnh mt

hng nhphng php chun. Nhc im ca phng php ny l ph h ca

cc dng khng c theo di, rt kh chn lc trong s cc dng v trong

cng mt dng, kh xc nh v s dng con chu nhng dng tt i thp.

(trch dn theo Nguyn Hu Phc, 2002)[12]

+ Phng php to n bi (Haploid breeding).

Nh ng dng ca cng ngh nui cy m t bo, hin nay mt s nc


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p dng to dng thun bng phng php nui cy bao phn, non

cha th tinh. Phng php ny gip cc nh chn ging rt ngn thi gian

to dng thun t 4 5 nm xung ch cn 2 3 nm (Chase, 1952)[33]. Vit Nam, cc nghin cu v cng ngh to cy n bi ng c bt

u tm hiu nghin cu ti Vin Di truyn nng nghip t nm 1995. Hin

nay kt qu bc u to ra mt s dng ng thun. (Dn theo Nng

Vnh v cng tc vin 2004)[25]

2.4.2. Hin tng u th lai, khi nim v ng dng trong to ging ng

u th lai l hin tng tng sc sng, kh nng chng chu v cuicng l nng sut cy trng v vt nui qua lai to, n v ang c p

dng rng ri trong nng nghip, v con lai thng cho nng sut cao hn cc

dng b m t 10 25%, thm ch n 90%. Chnh v vy hu ht cc ging

cy trng (c bit cc cy giao phi) v gia sc c s dng hin nay l cc

con lai F1. Ngh trng ng trn th gii vo nhng nm cui ca th k 20

c nhng b

c pht trin nhy vt nh ng dng nhng cng ngh ging laihin i. Ng lai khng nhng gp phn tng tng sn lng lng thc

ca nhiu nc m cn gii quyt nn i mt b phn dn c trn th gii.

N kch thch ngnh chn nui, ngnh cng nghip khc pht trin, lm

phong ph trn th trng xut khu ng lai v gp phn a ngh trng ng

nc ta pht trin, a nng nghip Vit Nam ng trong hng ng nhng

nc c ngh trng ng tin tin Chu (Trn Hng Uy, 2001)[21]. Ng lai

pht trin nhanh chng v hp dn nhvy l do ng dng tin b k thut v

u th lai, cc bin php k thut lin hon. Chnh ng lai kch thch cc

nh khoa hc m rng i tng v phm vi nghin cu nhm thu c cc

ging lai u th v phong ph hn.

Nhiu nh khoa hc c s nh gi thng nht l cc ging lai th h

mi hn hn cc ging lai c v kh nng chng chu vi cc iu kin bt li


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ca mi trng nhnng, hn, t xu, mt cao, cc loi su bnh hi ch

yu v cng ch ra rng cc ging lai th h mi c xu hng to ging c gc

l ngy cng hp hn (Duvich, 1984, Pendletn v cng tc vin, 1987);(Pepper, 1974) (dn theo Mai Xun Triu 1998)[18]

u th lai c th di truyn c, iu ny c cc nh khoa hc

nghin cu t lu. Nh bc hc ngi c l I. G. Kolreter ln u tin m

t hin tng tng sc sng ca con lai so vi cc dng b m ca n qua vic

lai gia Nicotiana Tabacum v Nicotiana Robusta vo nm 1760. Nm 1876

Charles Darwin qua vic nghin cu hng lot cc c th giao phi v t phi cc loi khc nhau nh:ng, u v nhn thy s hn hn ca cc loi

giao phi so vi loi t phi v cc tnh trng nh(chiu cao cy, tc ny

mm ca ht, s qu, sc chng chu v nng sut ht). Nhng kt qu nghin

cu ny c tc gi tng kt trong cun Tc ng ca giao phi v t phi

trong th gii thc vt (Dn theo Nguyn Th Lu, 1998)[9]. Ngi tin hnh

tp giao u tin ng vi mc ch nng cao nng sut ht l John Lorain.

Nm 1982 ng nhn thy rng vic trn ln cc loi ng khc nhau nh

ngi da lm s to ra loi ng c nng sut cao. Ngi u tin quan

st hin tng u th lai ng l Charles Darwin. T cc th nghim ca mnh

ng pht hin thy nhng cy giao phi c chiu cao hn cc cy t phi

l 20%. Chnh v nhng tng ca ng to tin cho nhng pht kin k

diu v u th lai ngy nay. T kt qu ca Charles Darwin 1871 gip cho

William James Beal (nh nghin cu ngi M) nm 1878 p dng thc tu th lai trong vic to cc ging ng lai gia ging. ng thu c nhng

cp lai hn hn cc ging b m v nng sut t 10% - 20% (dn theo Trn

Hng Uy, 1972)[24]

Trn c s hc thuyt di truyn ca Medel (1876) v l thuyt dng

thun ca Johansen. Ln u tin vo nm 1904 Shull tin hnh t phi


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cng bc ng to cc dng thun v thu c con lai c u th lai cao t

cc dng thun ny. ng c coi l ngi khi xng ra ging lai gia cc

dng. Nhng cng trnh nghin cu v ng m Shull cng b vo nm 1908 v1909 nh du s khi u ca cng tc chn to ging ng lai. Thut ng

Heterosistr thnh thut ng chung ch hin tng u th lai. Ngoi

Shull, cc nh di truyn hc ngi M nhEast, Heyse cng nghin cu u

th lai ng. Nm 1918 Jones xut s dng lai kp trong sn xut, h

gi thnh sn xut ht ging th vic p dng u th lai vo trng trt, chn

nui mi thc s pht trin nhanh chng (trch theo Mai Xun Triu,

1998)[18]

u th lai biu hin hu ht cc tnh trng ca t hp lai c

nhiu nh di truyn chia thnh cc dng biu hin chnh nhsau(Trn Hng

Uy, 1972, 1985)[24].

- u th lai v hnh thi.

Biu hin qua sc sinh trng v pht trin nhtm vc cy (chiu cao,ng knh gc). Kiesselback (1922) (dn theo Mai Xun Triu 1998)[18]

cho thy ng, con lai F1c ln ht tng hn h m l 11,1%, ng knh

thn tng 48% chiu cao cy tng 30 50%.v.v...., ngoi ra cn thy din tch

l, s lng v kch thc l, chiu di v s lng r, chiu di v s nhnh

c. v.v... cy lai u th hn hn b, m chng.

- u th lai v nng sut.y l hin tng quan trng nht i vi sn xut nng nghip, n

c biu hin qua s tng ln ca cc yu t cu thnh nng sut nh t l

ht trn bp, trng lng ht, chiu di bp, s hng ht / bp, s ht / hng, s

bp / cy.... Theo Richey (1927) (dn theo Trn Hng Uy, 1985)[23]. u th

lai v nng sut cy ng vi cc ging lai n gia dng vi dng c th t

nng sut t 193% - 263% so vi trung bnh b m (dn theo Trn Hng Uy,


25/118

1984)[22]

- u th lai v tnh thch ng.

c biu hin kh nng chng chu vi cc iu kin bt thun ca mi

trng sng nhhn, rt, su v bnh. Cc nh khoa hc s dng u th lai trong

chng trnh chn to ging ng lai c kh nng chng chu nhchu hn, rt.

-u th lai v tnh chn sm.

Biu hin t hp lai chn sm hn so vi b m, nguyn nhn l do s

tng cng hot ng ca qu trnh sinh l, sinh ho, trao i cht trong c

th t hp lai mnh hn b m (A.R. Hallauer, et al, 1990)[37]

- u th lai v cc yu t sinh l, sinh ho.

S tng hn so vi b m biu hin s tng cng trao i cht, tng

cao hn b m v mt s ch tiu sinh ho nh tng hm lng ng con

lai (ng dng sn xut ging ng ngt), ng giu m cht lng cao.

- Qua nhng ng dng thc t ch ra rng: Ng l cy in hnh nhtv s thnh cng trong ng dng u th lai trong sn xut nng nghip. M

nng sut ng vt trn cc ging ng truyn thng t 1 6 tn/ha/v. Cc

nh khoa hc tnh ton ging ng lai ng gp 60% v k thut canh tc

40% vo mc tng nng sut ng ( Nng Vnh, 2001, s 2). Nh p dng

u th lai m din tch trng ng lai Vit Nam tng t 0% vo nm 1990 ln

30% nm 1995 v n nm 2000 t l s dng ng lai t 65% tng din tchtrng ng trn c nc[19]

2.4.3. Cc hc thuyt v u th lai:

L thuyt v thc nghim v u th lai c nghin cu su nhm gii

thch hin tng cng nhto ra cc ging ng lai ngy cng u vit phc v sn

xut. u th lai l hin tng tng sc sng qua lai c nhiu nh khoa hc gii


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thch thng qua nhng thuyt khc nhau, nhthuyt tri (Bruce 1910, Collins 1921,

Jones 1917). Thuyt siu tri (Hull, 1945: East, 1912) Thuyt cn bng di truyn

(Mazer, Turbin, 1961), thuyt sinh l ho (Robinson, Emerson) (dn theo Ng HuTnh) [13]. Nhiu quan im gn y nht v u th lai c khuynh hng da vo

tc ng gen gii thch hin tng ny.

u th lai l mt hin tng sinh hc tng hp th hin cc u vit theo

nhiu tnh trng con lai F1khi lai cc dng b m theo ngun gc, xa cch

di truyn, sinh thi. S th hin u vit ca tnh trng (c nh gi theo cc

nh l

ng nu trn) con lai F1phi em li li ch cho tin ho v cho toging nhng iu kin sinh thi v canh tc xc nh. To ging u th lai l

con ng c hiu qu cao nhm tp hp nhiu tnh trng mong mun (Sc

sng, nng sut, chn sm, cht lng...) vo mt kiu gen. Do t hp cc ngun

gen t cc b m khc nhau, kiu gen ca con lai F1thu c nhng hiu qu

i mi v tng tc gia cc gen nhn cng nhtng tc nhn t bo cht.

C s di truyn

Tng tc gia cc alen Tng tc trong cc alen

Cc yu tb sung

Cc yu ttri

Cc yu tlin kt

Tnh d hpt


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Thuyt tri Thuyt siu tri

S u th lai ca Crow (Dn theo Trn Duy Qu)

Nhvy, nguyn nhn di truyn ca hiu ng u th lai c xem xt

nhng hiu qu gia nhng tng tc sau:

+ Tng tc gia cc gen cng locus.

+ Tng tc gia cc gen khc locus.

+ Tng tc gia nhn v t bo cht.

2.4.3.1. Gi thit lin quan ti tng tc gia cc gen cng locus, hiu qutri, siu tri.

L hin tng con lai F1thu c mc d hp t no v cc gen tri

c tch lu v th hin ln t cc gen ln gy hiu qu xu, dn ti con lai F1

u th hn b m mang cc gen ln trng thi ng hp t, tc con lai F1

khc phc nhng khim khuyt cc dng b m (cc dng t phi);

P AA bb CC dd x aa BB cc DD

F1 Aa Bb Cc Dd

P l b m.

F1 l con lai.

Cc alen ln a, b, c, d c hi hoc c hiu qu yu v biu hin kiu

hnh ca tnh trng, mi b m c hai gen ln ng hp t. con lai F1cc

gen ln c lp trng, bn gen tri pht huy tc dng, n c u th lai hn

hn b m.


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Trng hp kiu d hp t c tng tc c bit dn ti hiu qu th

hin mnh hn so vi cc kiu ng hp t - l hiu qu siu tri.

AA < Aa > aa

C s v hiu qu tri, siu tri c kim chng r s i lp gia

sc mnh (u th) ca con lai v mc th hin tnh trng yu cc dng t

phi, do cc dng t phi c th xut hin nhiu gen ln gy hiu qu xu.

i vi cc tnh trng s lng do nhiu gen kim tra, th hin ln ca tnh

trng tng khi cc yu t tri tng v mc d hp t tng, iu hon ton

ph hp vi cu trc di truyn ca con F1.

Nu xem xt gc ho sinh, biu hin siu tri c th gii thch theo

gi thit v liu lng v to sn phm mi con lai. Theo gi thit v liu

lng enzym ta c dng Aa cho mc liu lng ti u, dng aa thiu ht,

dng AA - d tha, t dn ti con lai F1 (Aa) c u th hn cc b m

(AA, aa). C th dn mt v d v to sn phm mi con lai: ng locus E

kim tra enzym esteraza, ngi ta nghin cu hai trng thi ca enzym ny ldng F v dng S. Phn tch in di cho thy, t cy ng hp t E FEF thu

c esteraza dng F, t cy ESESthu c esteraza dng S, cy lai EFESthu

c ba bng trn ph in di ng vi hai dng F, S v dng mi F/S nm gia

F v S. C th sn phm mi (lai) xut hin nhmt cu trc hon chnh v

hiu qu hn trong vic ng gp v th hin tnh trng (Nguyn Hng Minh,

1999) [10,174]

2.4.3.2. Gi thit lin quan ti tng tc gia cc gen khc locus.

Nhm tc gi ca gi thit ny nhn nh rng dng tng tc gia cc

gen khc locus gy nn hiu qu u th v th hin tnh trng con lai F1so

vi b m nhtheo m hnh AA bb x aa BB Aa Bb trong tng tc gen

khc locus, hot ng ca gen ny c th b ph thuc vo gen kia. Trng


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hp mt gen trng thi ln c th gy c ch th hin kiu hnh ca cc gen

khc. Gen ln ny tn ti b m, song con lai F1n c lp trng bi

gen tri, do hiu qu c ch khng xy ra. Kt qu l th hin ca tnhtrng F1c u th hn so vi b m. S biu hin kiu hnh ca tnh trng c

th do hiu qu tc ng ca gen chnh (gen ch) phi hp vi tc ng ca

mt lot gen ph (gen bin hiu, gen iu chnh). con lai F1c th thu c

cc t hp i mi gia gen ch vi gen iu chnh c hiu qu cao hn trong

s th hin kiu hnh ca tnh trng so vi b m. Sau khi phn tch tng hp

cc kiu t

ng tc ca cc alen cng locus v khc locus, cho php nhnnh c hai kiu tc ng theo chiu ng v theo chiu i ca cc alen.

Nhng tc ng c hnh nh khi nim v cc mi cn bng di truyn. Tnh cht

cn bng ni ln mt cu trc di truyn no th hin tnh thch ng tt vi

iu kin mi trng. Ngc li, mt kin trc km (khng) cn bng khi t hp

cc alen ca kiu gen km n nh, km cn i trong qu trnh pht trin ca

cc tnh trng dn ti kiu gen km thch ng (Nguyn Hng Minh,1999)[10]

2.4.3.3. Gi thit lin quan ti tng tc nhn t bo cht.

Khi lai cc c th khc nhau v mt di truyn, ngay sau khi th tinh,

hnh thnh nhng mc khc nhau v mi quan h nhn t bo cht, do

nhng ngun gc khc nhau v nhn v bo cht ca cc c th giao phi.

Nhng i mi khc nhau thu c trong mi quan h nhn t bo cht l rt

quan trng. C th mt s ln phn chia t bo, mt s l

ng gen no cmc hot ng tng hn, t nhiu s kin khc nhau ca qu trnh trao i

cht c tng cng. cy ng, nghin cu hot tnh h hp ca ty th cy

non 4 5 ngy tui, Sarkissan (1969) cho thy hot tnh ny cy lai tng

hn hn so vi cc dng b m (dn theo Nguyn Hng Minh 1999 [10, 178].

Kt qu o hot tnh cc enzym h hp c Linh lng, H.Jacob v cng s


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(1967) cho thy, trng hp lai gia cc dng t bin khc nhau thu c

hot tnh enzym thi gian u sau th tinh tng gp 5 10 ln so vi tr ng

hp t th phn(dn theo Nguyn Hng Minh 1999[10,180-184]) . Gi thitv tng tc nhn t bo cht c th gii thch s iu ho qu trnh pht

trin c tng tc ngay t khi sau th tinh trng hp lai. y c th ni,

thng tin di truyn c tr ho ngay t khi sau th tinh, tri vi trng hp

t phi, thiu cc tnh th mi m cho th hin thng tin di truyn t

ngay sau khi th tinh (c th mnh ln). (Dn theo Nguyn Hng Minh)[10]

2.4.4. D on u th lai.

c lng mc th hin tnh trng con lai F 1ni chung,

ngi ta s dng thng s gi l tri (Hp), n din t mc vt

ln ca tnh trng F1so vi gi tr trung bnh ca b v m.

i tri (Hp) c tnh theo cng thc.

F1- PbHP = --------------- x 100Pb

F1: gi tr tnh trng ca t hp lai

Pb : gi tr trung bnh ca tnh trng b m

Theo cng thc trn, tri c th c l gi tr bt k t - n + ,

chng ta c th phn bit mt s trng hp sau:

- - < Hp < - 1 L hin tng siu tri m (u th lai m).

- - 1 Hp < - 0,5 L hin tng tri m.

- - 0,5 Hp + 0,5 L hin tng di truyn trung gian.

- + 0,5 < Hp + 1 L hin tng tri dng.


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- + 1 < Hp < + L hin tng siu tri dng (u th lai dng).

u th lai phn ln c xem xt nhtnh u vit ca con lai F1so vi

b m.

Hin nay, trong chn to ging nhng thc nghim ph bin thng p

dng l xc nh KNKH ca cc b m bng mt s phng php truyn

thng nhlai Dialen, lai nh. Nhng cc thc nghim ny i hi nhiu cng

sc. Mt dng no khi lai vi nhiu dng khc nhau cho cc F1m c gi

tr trung bnh v ln ca tnh trng cao, nu ni mt cch so snh th dng

y c KNKHC cao. Nu trong cc F1 c kiu no cho th hin tnh trngvt hn hn gi tr trung bnh trn, hay ni mt cch khc l t hp lai c th

y c KNKHR cao. Theo Turbin (1969) (dn theo Nguyn Hng Minh) 1999[

10,179] v c bn KNKHC c kim tra bi cc hiu ng cng tnh ca cc

gen, cn KNKHR lin quan ti hiu ng tri.

Ngoi ra, d on u th lai ca tnh trng no ca con lai F1c

th s dng cc m hnh phn tch tng quan gia cc tnh trng cc b mtham gia vo t hp lai. Ngi ta cn c th s dng cc phng php RAPD,

PCR d on th hin tnh trng con lai F1qua vic phn tch gen.

2.4.5. KNKH, phng php nh gi KNKH:

2.4.5.1. Khi nim KNKH.

KNKH l mt thuc tnh c ch nh di truyn, c truyn li cho

i sau qua t phi v qua lai. KNKH c th hin bng gi tr trung bnhca u th lai, quan st tt c cc cp lai v chnh lch so vi gi tr trung

bnh ca mt cp lai c th no . Gi tr trung bnh biu hin KNKHC

(General combining ability GCA), c biu th bng gi tr u th lai trung

bnh ca b m tt c cc t hp lai. Cn chnh lch ca t hp lai c th

no vi gi tr u th lai trung bnh ca n biu hin KNKHR (Specific

combining ability SCA. Sprague 1957)[49] cho rng nh gi dng v


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KNKH thc cht l xc nh tc ng ca gen.

Sprague v Tatum chia tc ng gen lin quan n KNKH thnh hai loi:

KNKHC c xc nh bi yu t di truyn cng, cn KNKHR xc nh bi yut c ch, tnh tri, siu tri v iu kin mi trng. Quan h gia KNKHC v

KNKHR thng qua tc ng tri v c ch c xc nh bng vic tnh ton cc

phng sai di truyn, di truyn tri, c ch tri (R.W. Allard, 1960: L.L. Darrah v

A.R.Hallauer, dn theo Trn nh Long, Hong Vn Phn, 1990) [ 8,615 621].

Kt qu nh gi KNKH ca cc dng b m, thng qua cc tnh trng trn t hp

lai ca chng, gip chng ta c quyt nh chnh xc v vic gi li dng c

KNKH cao, loi i cc dng km c KNKH thp.

Trong khi xc nh KNKH cc nh nghin cu gp phi mt s kh

khn, l tnh khng o m c ca chng. d on u th lai ngi ta

c gng tm nhng tnh cht hnh thi, sinh l, sinh ho, d o m v c

tng quan cht ch vi KNKH nhhot cht sinh trng, lng azot v pht

pho trong ht, hot ng quan ho ca chloroplast... th nhng thng tin v

KNKH thu c bng cch hoc khng chnh xc, hoc i hi chi ph nhiusc lc v phng tin. Theo s liu ca Gama v Hallauer [35] th h s tng

quan gia nng sut dng t phi vi nng sut ging lai l 0,09 0,11 cn

nhng c tnh khc ca dng vi nng sut ging lai khng qu 0,14. iu

chng t rng nhng c im ny cha th dng lm tiu chun chn v

KNKH, tuy chng rt cn thit trong qu trnh to dng thun mi.

Vy, thu c nhng s liu cn thit v KNKH ca cc vt liu to

ging, chc chn nht l lai th v so snh cc th h con lai. Cng vic ny

kh nng nhc v tn km, v n lin quan n khi lng ln lai to v th

nghim cc cp lai thu c. tin hnh hp l cng vic ny cc nh khoa

hc a ra nhng s lai v cc phng php nh gi KNKH khc

nhau. Nhng hai phng php chnh c cc nh khoa hc p dng l:

+ Lai nh (Top cross).


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+ Lai lun phin (Diallel cross).

2.4.5.2. Phng php nh gi KNKH

2.4.5.2.1. nh gi KNKH bng phng php lai nh

Lai nh l phng php th ch yu xc nh KNKHC (GCA) do

Devis xut nm 1927, Jenkins v Bruce s dng v pht trin. Cc dng

hoc ging cn xc nh KNKH c lai cng vi mt dng chung gi l cy

th (Tester). Phng php ny rt c ngha giai on u cu qu trnh

chn lc, khi khi lng dng cn qu ln, khng th nh gi bng phng

php lun giao. Vic chn ng cy th s l yu t quan trng quyt nh s

thnh cng ca php lai nh, cng vic ny tu thuc vo ca nh chn

ging. C tc gi chn cy th c nng sut thp v n lm r s sai khc gia

dng em th. Mt s tc gi khc, c bit cc nh to ging thng mi

thng chn cy th l dng u t nng sut cao v s c xc xut to ra c

ging nhanh (theo Ng Hu Tnh v cng tc vin, 1997)[13]. Tuy nhin mt

ch tiu chung cc nh to ging chp nhn l cy th khng c quan h hhng vi cc dng em th. tng tin cy ngi ta thng dng hai hoc

nhiu cy th c nn di truyn rng, hp khc nhau (theo Ng Hu Tnh,

Nguyn nh Hin, 1996)[16]. Qua nghin cu mt s tc gi thy rng cy

th tt nht l dng thun c lng allen tri v ln bng nhau (theo Krulirski

v Adam Chich, 1979) (dn theo Ng Hu Tnh, 1990)[17]

Vic chn cy th c nh h

ng ln n kt qu nh gi KNKH cacc vt liu trong lai nh, c th ni rng yu t thnh cng trong lai nh l

chn ng cy th. Cy th c nn di truyn rng (ging tng hp, ging lai

kp...) hoc c nn di truyn hp (dng thun, lai n...)

tng chnh xc ngi ta thng dng 2 hoc nhiu cy th. Cy

th c nng sut thp thch hp hn cho vic nh gi dng v n lm r s

khc bit nhau gia dng em th, trong khi cy th c nng sut cao s


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che lp s khc bit . Tuy nhin xut pht t mc tiu kinh doanh cc nh

to ging thng mi thng s dng cy th c KNKH cao trong lai nh

c xc sut to ra c ging ln hn cy th c KNKH trung bnh hoc thp(A.R Hallauer 1990)[50]. Cy th c nn di truyn rng c nhiu tc gi

nghin cu v i n kt lun: Cy th l cc loi ging th nghim, cc gia

nh fullsib, cc t hp lai n, cc dng n ho l tt nht nh gi

KNKH ca cc dng. Mt s tc gi xc nh KNKH ca cc vt liu ng ca

CIMMYT bng lai nh vi cy th l Tuxpeno v ETO xc nh c mt

s t hp lai c u th lai cao vi mt s qun th v vn gen ca CIMMYT

(Theo D.L Beck, S. K. Vasal, 1990)[29]

Quan h gia cy th vi cc dng.

Khi nghin cu v quan h cy th vi dng thun, mt s tc gi

kt lun: Phn ng ca cc dng vi cy th biu hin tnh trng nng xut

th cng biu hin cc tnh trng khc, nhng mc biu hin c th khc

nhau. Ngoi ra cn thy s dng cy th c c s di truyn qu rng hoc c

mt kh nng mnh trong vic truyn mt s c im no l khng nn, v

n khng cho php biu hin mt cch r rng s khc nhau ca cc dng th

(Trn Hng Uy, 1985)[23]

Th KNKHC c th tin hnh sm i t phi S4 hoc S5

(G.F.Sprague 1942)[48] v c th tin hnh ngay vi ging ban u nh t

phi (Trn Nh Nguyn v Luyn Hu Ch, 1971) [11]. Trong nghin cu

KNKH ca cc vt liu ng Vit Nam, hai cy th l T trng a phng vng lai s 5 c dng nh gi KNKHC cho 200 ging, dng a

phng v nhp ni, cho thy cc dng c KNKHC cao nhdng s 24, 1 v

10, cc tc gi i n nhn xt rng cc dng t phi c KNKH cao giai

on sm vn gi c c im ny giai on sau (Nguyn Vn Cng,

1995) [1]. Lai nh rt c ngha giai on u ca qu trnh chn lc dng,

khi khi lng dng qu ln khng th tin hnh nh gi bng phng php


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lun phin. a s cc dng c KNKH tt (u th lai cao) vi cy th u c

KNKH tt vi nhau v ngc li, do sau kt qu ca lai nh cc dng c

KNKH tt c gi li nh gi tip bng lun giao [14]2.4.5.2.2. nh gi KNKH bng phng php lai lun phin (Diallel cross)

Phng php nh gi KNKH bng lai lun phin c Sprague v Tatum,

xut vo nm 1942[33]. n nm 1947 th East s dng h thng lun giao

xc nh KNKH ca cc kiu gen trong th nghim chn ging ng. Sau East

v mt s tc gi nhGriffing (1956) [36]. Hayman (1954) [38] s dng v

pht trin thm h thng lun giao.

Lun giao l h thng lai th, cc dng c lai vi nhau theo tt c cc

t hp c th. Qua phn tch lun giao chng ta thu c cc thng tin v:

- Bn cht v c lng cc ch s di truyn.

- KNKHC v KNKHR ca b m v con lai.

Ngy nay lun giao l phng php c s dng ch yu v ph bin

ca cc nh chn ging mi quc gia, n tr thnh cng c c lc nht

trong chn v nh gi vt liu ca qu trnh to ging. Phn tch cc t hp

lai lun giao c gi l phn tch lun giao, cho chng ta bit bn cht v gi

tr thc ca cc tham s di truyn, KNKHC v KNKHR ca cc b m biu

hin con lai. Trong phn tch lun giao c hai tip cn chnh, l tip cn

Hayman v tip cn Griffing.

+ Phng php phn tch Hayman.

L thuyt lun giao c pht trin bi Jinks v Hayman (1953, 1954)

[30]. Phng php ny gip chng ta xc nh gi tr di truyn ca cc vt

liu b m, qua vic phn tch phng sai v hip phng sai ca cc dng b,

m v con ci. Trn c s phng sai v hip phng sai m t thnh

th, sau da vo v tr tng dng b, m trn th ta c th c nim v


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c ch di truyn ca chng. Vic xc nh cc tham s di truyn nu trn ch

t c kt qu chnh xc khi b m tho mn 6 iu kin m Hayman nu

ra l: Mt l ng hp t ca dng b m ; Hai l: khng c hin tng aalen (mi locut ch c 2 alen); Ba l: khng c tng tc phi alen; Bn l cc

gen phn phi c lp dng khi u; Nm l: qu trnh lng bi ho theo

kiu x dc (tc l hin tng phn bo bnh thng); Su l: khng c s

khc nhau gia lai thun v lai nghch. Nu b, m khng tho mn cc iu

kin vic c on s b sai lch.

+ Ph

ng php Griffing.Nm 1956 Griffing [36] s dng lun giao xc nh KNKHC v

KNKHR. T kt qu nhng c lng ny cng c th tnh c thnh phn

di truyn di cc dng phng sai di truyn cng (A2) v tri (B

2) mt vi

trng hp. H thng lun giao ca Griffing c hai mu hnh l mu hnh

c nh (Model I) v mu hnh ngu nhin (Model II). ng xut 4

phng php th nghim phn tch lai lun phin s dng m hnh ton hc

thng k phn tch KNKH ca cc dng m cho n nay vn c cc nh

chn ging trn th gii s dng.

Tu theo mc ch nghin cu v iu kin c th m cc nh to ging

la chn mt trong cc phng php trn cho ph hp. Nu nghin cu ton

din ngi ta thng s dng phng php 1. So snh t hp lai vi b m ta

s dng phng php 2. Cn mun nghin cu tc ng ca m ti t hp lai

ta nn s dng phng php 3. Khi p dng phng php 1 v 2 s kt lunc chnh xc cc dng em th c lai theo hai hng thun v nghch,

nhng i hi nhiu cng sc, thi gian v tin ca. Trong thc t chn ging

ngi ta thng p dng phng php 4. V phng php 4 khi lng cng

vic phi lm t hn so vi 3 phng php kia m vn xc nh c yu cu

ti thiu cn thit v nh gi KNKH.

M hnh ton hc ca phng php lun giao c Sprague v Tamtum


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[48] xut nm 1942 nhsau:

bXij = + gi+ gj+ sij+ rij+ 1/b * EiikTrong : k=1

- Xij: Trung bnh ca cc kt qu lai dng i vi dng j trong tt c cc

ln lp li.

- : Tc ng trung bnh ca th nghim.

- giv gj: Tc ng ca KNKHC ca cc dng i v dng j.

- sij : Tc ng ca KNKHR gia hai dng i v j.

- rij : Tc nh tng h gia hai dng .

- Eijk : Sai s ngu nhin.

M hnh ton hc ny c p dng linh hot cho c 4 phng php th

nghim trn. phng php 2 v 4 khng c cc cp lai ngc nn trong m

hnh tnh ton khng c yu t r ij, khi tnh ton cn lu vic p dng tng

cng thc cho tng phng php c th.

S dng lun giao nh gi KNKH v nng sut, khi lng thn, khi

lng ht v mt s tnh trng khc ti 6 im Colombia, Equado, n ,

Thi Lan. Mxico v Zimbabue, cc tc gi nhn thy rng KNKHR ch

sai khc c ngha ch tiu khi lng ht cn KNKHC th s sai khc c

ngha cc ch tiu theo di (dn theo Mai Xun Triu, 1998)[18].

Quan h KNKH vi kh nng khng bnh.

nh gi kh nng khng bnh bch tng l ng ca cc t hp lai lun

giao, mt s tc gi c nhn xt rng KNKHC nh hng mnh hn KNKHR

trong vic khng bnh ny, nhng dng khng bnh thng c gi tr KNKHC

thp, cc t hp lai mn cm vi bnh thng c gi tr t hp ring m (S. K.


38/118

Dey,. Mahajan, 1989)[33]

Khi nh gi KNKH vi kh nng khng bnh thi thn, thi ht v

bnh than en ng vi 15 t hp ca 6 dng theo s 4 Griffing, cho ktlun rng KNKHC ng vai tr quan trng i vi tnh khng bnh than cc

t hp lun giao (M. Odiemal v I, Kovacs, 1990)[42]

Biu hin KNKH ca cc dng cc tnh trng.

Mt s tc gi sau khi s dng lai lun giao theo s Griffing

1956[36] nh gi vt liu to ging tnh trng nng sut ht, cc tc gi

khc nhau nghin cu trn cc vt liu khc nhau cho mt s kt lun di

y.

Kt qu nh gi KNKH ca 6 dng ng thun ngn ngy, cho thy cc

dng s 1 v 2 cho KNKHC cao, c bit dng 2 cn c KNKHR cao, nn s

dng vo t hp lai c th (Trn Hng Uy v cng s, 1985) [24].

nh gi KNKH ca 9 dng thun cng ngun gc, nhng cch to

khc nhau, trn tnh trng nng sut ht chn c cc dng c KNKHC

cao l 137 FSI, DC7, Mo 17, cc dng c KNKHR cao nhdng FS137, vi

dng 6 v 7, dng DC7 vi Mo 17 (Ng Hu Tnh v cng s, 1993) [15].

S dng hai khi lun giao nh gi KNKH ca cc dng fullsib v

cc dng t phi, cc dng fullsib c ngh dng lm trung gian hoc xen

k trong qu trnh to dng t phi chn to cc dng c KNKH cao[23].

2.5. Tnh hnh sn xut v s dng ng trn th gii v

trong nc

2.5.1. Tnh hnh sn xut v s dng ng trn th gii

Mt trong nhng tin b k thut nng nghip thnh cng rc r nht

th k 20 l ng lai. Ngh trng ng trn th gii vo nhng nm cui ca th

k 20 c nhng bc tin nhy vt nh ng dng rng ri cng ngh u th


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lai, k thut nng hc tin tin v nhng thnh tu to ln ca cng ngh sinh

hc, cng ngh ch bin v bo qun, cng ngh tin hc,.... gp phn gii

quyt nhu cu lng thc v protein ng vt cho hn 6 t ngi trn hnhtinh chng ta. Ng lai pht trin nhanh chng v hp dn nhvy l do ng

dng tin b k thut v u th lai, cc bin php k thut lin hon. Chnh

ng lai kch thch cc nh khoa hc m rng i tng v phm vi nghin

cu nhm thu c cc ging lai c u th lai ln hn v phong ph hn.

Cy ng l mt loi cy c nn di truyn rng, thch ng vi nhiu vng sinh

thi khc nhau, do vy ng

c trng hu ht cc n

c trn th gii. Sn phm tng c s dng vi nhiu mc ch khc nhau nhl lng thc, thc phm cho

ngi, thc n chn nui, nguyn liu cho cng nghip v hng ho xut khu.

Thc t, ng cung cp lng thc nui sng 1/3 dn s th gii, cc

nc trng u s dng ng lm lng thc hay thc thm nhng mc

khc nhau theo thng k trn th gii s dng 21% sn lng ng lm lng

thc cho ngi. Trong cc vng Trung M, Nam v chu Phi dng ng

lm lng thc chnh. Cc nc vng ng nam Phi s dng 85% sn lng

ng lm lng thc. Vng ng nam v Thi Bnh Dng s dng 39%, cn

vng ng u v cc nc trong SNG s dng 40% sn lng ng lm

lng thc (Theo Ng Hu Tnh v cng tc vin)[15]. Hng nm trung bnh

mi ngi dn Mexico tiu th trn 100kg ng ht lm lng thc ch yu

di dng bnh t bt.

Ng ngoi s dng lm lng thc, nhng gn y ng cn l cy thc

phm, ngi ta dng bp ng bao t lm rau cao cp, ngh ny pht trin rt

mnh Thi Lan v i Loan... S d ng rau c a chung nhvy l v

n sch, an ton v c hm lng dinh dng cao: cht bo 0,2%, hm lng

protein 1,9% so vi khi lng ti, hydrat cacbon 8,2mg/1kg ng ti cao

hn hn cc loi rau cao cp khc. Ngoi ra ng rau cn cha nhiu vitamin,


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khong cht: Ca, Fe, P... (Ng Hu Tnh 1997)[15]

Nhng nm gn y xu hng s dng ng lm lng thc gim dn, s

dng lm thc n gia sc tng nhanh. Qua iu tra thc n tng hp cho giasc c ti 70% hm lng cht tinh ly t ng. Theo thng k ca Cao c

im 1988[3], cho thy cc nc c nn nng nghip pht trin hu ht s

dng ng lm thc n gia sc nh: Php 90%, M 89%, Rumani 69%... cn

cc nc SNG trng khong 20 triu ha ng, trong ch s dng 3 triu ha

dng ly ht, cn li ly thn, l chua lm thc n cho gia sc.

Ng cn l nguyn liu cho cc nh sn xut ru, cn, tinh bt, du,glucoza, bnh ko.... Ngi ta sn xut t ng ra khong 670 mt hng

khc nhau ca cc ngnh cng nghip thc phm, cng nghip nng, cng

nghip nh (Ng Hu Tnh)[13]

Hng nm lng ng lu thng trn th trng th gii khong 90 triu

tn, cc nc xut khu chnh nh l M, Php, Achentina, Trung Quc v

Thi Lan. iu ny cho thy ng ng hng u trong cc mt hng nng snc t l lu thng trao i ln trn th trng quc t.

Ng lai c con ngi s dng cch y gn 1 th k, t c

nhng thnh cng nh ngy nay, qu trnh pht trin ng lai c chia lm

ba thi k (Dn theo Nguyn Th Hng 2003)[6]

Thi k 1. T lc con ngi bit li dng u th lai trong chn ging

ng (1900) ko di n nhng nm 1920. Giai on ny do hiu bit cn hnch, trnh kinh t k thut cn thp, ng lai tn ti nhmt loi ging lai

ci lng gia cc ging vi nhau (ging ng th phn t do OPV). c

im ca cc ging ng thi k ny l nng sut t thp 1,5 1,6 tn/ha, hiu

qu sn xut ng khng cao. Ng lai thi k ny ch yu c trng M,

cc nc chu u (Nguyn Th Hng 2003)[6]


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Thi k 2 (1920 1960).c im chnh ca thi k ny nh cc kt

qu thu c trong qu trnh chn to dng thun, cc ging lai kp c s

dng rng ri. Nng sut ng tng nhanh, vo cui giai on ti nc Mnng sut bnh qun 3 tn/ha, nh trng cc ging lai kp nng sut ng M

tng trung bnh 60kg/ha/nm, trong sut thi gian di khong 30 nm. Giai

on ny ng lai kp c s dng rng ri ti M, Canaa, cc nc chu

u v vng ng [6].

Thi k 3 (t 1960 n nay).Nh tc ng ca cc nghin cu mi v

nhu cu ca sn xut hng ho, hng lot ging lai n ra i, thay th dncc ging ng kp nng sut thp, ng u km. Ti nc M nh s

dng cc ging ng mi, nng sut ng hng nm tng gp hai ln thi k

trc, t mc 118kg/ha/nm. Cng vi vic to ra cc ging ng mi, ng

lai tr thnh mt loi hng ho quan trng nht trong sn xut ng mi, ng

lai tr thnh mt loi hng ho quan trng nht trong sn xut ng mi, ng

lai tr thnh mt loi hng ho quan trng nht trong sn xut ng, iu nykch thch cc c s nghin cu, cc cng ty tnhn tham gia vo vic chn

to, phn phi ht ging ng lai, nh vy ng lai c s dng trn phm vi

ton th gii, vi din tch ngy cng ln, em li cho loi ngi lng sn

phm khng l.

Bng 2.1. Din tch, nng sut v sn lng ng trn th gii

giai on t 1998 2000

Din tch

(Triu ha)

Nng sut

(T/ha)

Sn lng

(Triu tn)Tn nc

1998 1999 2000 1998 1999 2000 1998 1999 2000

T. Th gii 138,9 139,2 139,8 44,20 43,44 43,36 614,1 604,5 596,2

Bc Tr/M 40,46 38,96 40,48 68,75 69,37 72,56 27,82 270,2 343,3


42/118

Chu Phi 23,3 25,56 25,39 15,74 18,88 16,99 39,84 40,60 43,56

Chu 43,66 44,65 41,2 33,93 37,75 34,92 174,3 168,6 143,8

(Ngun:s liu thng k nng lm thu sn 2000)

Din tch trng ng trn th gii nin v 2002 2003 t vo khong

142 triu ha, t l s dng ng lai bnh qun khong 73 85%, nng sut bnh

qun 4,3 ha. Cc nc c t l s dng ng lai cao l M l 100% m phn

ln ng n chim ti 90%. Nhiu ging ng lai ni ting ca M c to rabi cc cng ty: lowa, Pioneer, Dekalb... Ngy nay, nng sut ng ti cc

im nng sut cao M t 15 18 tn/ha, nng sut th nghim t 25

tn/ha (Nguyn Th Hng 2003)[6]

chu , Bc Triu Tin s dng 100% l ging ng lai trong sn

xut tip sau l Trung Quc l nc ng u chu v nng sut, sn

lng v th hai trn th gii v din tch v sn lng ng vi din tch 24,8triu ha tng sn lng 121,3 triu tn, nng sut bnh qun t 4,85 tn/ha, t

l s dng ging ng lai chim ti 90%[27]. Trung Quc bt u nghin cu

ng lai t nm 1912, nm 1928 a ra sn xut nhiu ging ng lai, din

tch trng cc ging ng lai nm 1994 t 18,45 triu ha chim 87,7% din

tch trng ng (Trn Hng Uy 2001)[21]

Trong 10 nm (1990 2000) t l tng trng v din tch ng ton thgii l 0,7%, v nng sut l 2,4% v v tng sn lng 3,1%, iu ny cho

chng ta thy rng chnh s tng nhanh v nng sut gp phn tng sn

lng ng trn th gii.

Trong 10 nm (1990 2000) t l tng trng v din tch ng ton th

gii l 0,7%, v nng sut l 2,4% v v tng sn lng 3,1%, iu ny cho


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chng ta thy rng chnh s tng nhanh v nng sut gp phn tng sn

lng ng trn th gii.

Qua bng s liu trn cho thy din tch ng trn th gii tng chm, nngsut tng nhanh c bit cc nc Bc Trung M c nng sut v sn lng tng

cao hn cc khu vc trng ng khc trn th gii. N chim ti hn 50% v sn

lng nhng din tch ch chim 1/3. iu chng t rng y l vng tp

trung cc quc gia c ngh trng ng pht trin c nng sut ng cao nht th

gii, nng sut bnh qun khu vc ny khong 8,4 tn/ha. Cn khu vc chu

c nng sut bnh qun ch t 3,4 tn/ha, chu Phi l 1,7 tn/ha.Bng 2.2. Bng sn lng ng ca mt s nc sn xut ng ln

trn th gii (2003)

Tn ncDin tch

1000 ha)

Nng sut

Tn/ha)

Sn lng

1000 tn)

M 28.583,0 8,7 220.066,0

Trung Quc 114.175,0 4,85 115.497,6Bc triu tin 17.0 4,11 70,0

Nht bn 65 2,46 160,0

n 6.083,0 1,5 9.124,5

Phi lippin 2.724,0 1,8 4.478,4

Innexia 3.737,0 3,25 10.910,1

Thi Lan 1.150,0 3,91 4.500,0

Bng 2.3. T l s dng ng lai mt s nc (theo CIMMYT 2000-2003)

Tn ncTng din tch ng

(1000 ha)

T l s dng ng lai

(%)

M 28.583 99

Venezuela 443 88


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Achentina 2.789 49

Braxin 13.668 68

Zimbabue 1.528 90Thi Lan 1.540

Vit Nam 909,8

Ngy nay vi s pht trin nhanh, mnh ca cng ngh sinh hc ng

dng ca nn di truyn hc hin i, gip cc nh chn ging ch trong

thi gian ngn c th to ra dng thun, cng vi s pht trin chuyn npthnh cng cc gen khng bnh vo cy ng gip cho n c kh nng

khng su bnh gip cho ngh trng ng trn th gii ngy cng pht trin.

2.5.2. Tnh hnh sn xut v s dng ng lai Vit Nam

Cy ng c a vo trng Vit Nam cch y khong 300 nm

(Ng Hu Tnh)[13], n c coi l cy mu chnh, thch ng rng chu thm

canh cao l loi cy ng u v nng sut trong cc loi cy lng thc. Ngtrng nhiu vng sinh thi khc nhau v trng nhiu v trong nm.

Bng 2.4: Din tch, nng sut, sn lng ng Vit Nam

giai on 1999-2003

NmDin tch

(1000 ha)

Nng sut

(t/ha)

Sn lng

(1000 tn)

1999 686,9 25,5 1751,9

2000 730,2 27,5 2.005,9

2001 729,5 29,6 2161,7

2002 816,0 30,8 2511,2


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2003 909,8 32,2 2933,7

(S liu thng k nng lm nghip, thu sn tng cc thng k 2003)

T s liu bng trn cho thy nng sut ng ca Vit Nam tng t 25,5

t/ha (nm 1999) ln 32,2 tn (nm 2003). Theo d bo trong nhng nm ti

Vit Nam cn khong 5 6 triu tn ng lm lng thc v thc n chn

nui (dn theo Trn Hng Uy,2001)[19]

p ng c nhu cu ngy cng tng v sn lng ng ngoi vic

y nhanh tng din tch trng ng, cng tc chn to nhng ging ng lai

mi c nng sut cao, c kh nng chng chu, ph hp vi iu kin tng

vng sinh thi khc nhau l cng vic rt cn thit i vi ngh trng ng

nc ta. Vit Nam tip cn vi ng lai t nhng nm 1960 c nhng nghin

cu v chn to v s dng cc ging ng lai song do vt liu khi u ngho

nn, c s vt cht cha p ng c mt s khu trong qu trnh sn xut

ng ging, mi n nm 1990 ng lai mi pht huy c vai tr ca n. T

din tch 5 ha trng th nghim nm 1990 n nm 1996 din tch tng ln

230.000 ha chim 46% din tch trng ng c nc v n nm 2003 din

tch c nc t 909.8 00 ha.

Vit Nam, cng tc iu tra, thu thp ngun vt liu ng a phng

c bt u tin hnh t nhng nm 60. Cc nh nghin cu i n thng

nht ng a phng Vit Nam tp chung ch yu vo hai loi ph l rn

(Zea may L. Indurata Stert) v ng np (Zea may L. Ceratina Kulesh).

Qu trnh chn to ging ng ti Vit Nam thc s bt u vo nhng

nm 1970[10]. C th chia lm ba thi k chnh sau.

Giai on 1: y l giai on thu thp ngun gen, giai on ny nh s

gip ca cc Vin nghin cu ng ni ting VIR, chng trnh nghin cu


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thu thp, phn loi c ngun gen kh phong ph t tp on ng trong

nc v th gii.

Giai on 2: y l giai on chn to v nhp ni cc ging ng th

phn t do (1973 1990): Chng trnh nghin cu ng Vit Nam nhp ni

v chn to hng lot ging ng c nng xut cao, ph hp vi iu kin kinh

t k thut ca Vit Nam. ng ch l cc ging ng th phn t do: TH

2A; TH2B; VM1; TSB2; MSB 49; Q2; VN2... Din tch trng ng th phn t

do c thi im cao t trn 50% din tch gieo trng ca c nc.

Giai on 3: L giai on chn nhng ging ng lai qui c (1990 nnay). Chng trnh nghin cu chn to ging ng lai quy c c cc nh

khoa hc Vin nghin cu ng xut rt sm, t nhng nm 1970 1973

mt s nc thuc khi x hi ch ngha. Kt qu ca vic chuyn giao trn

khng thnh cng do s khc bit v iu kin a l, khi hu gia Vit Nam

v cc nc. khc phc kh khn trn, cc nh khoa hc Vit Nam chn

dng v sau 25 nm nghin cu cc nh chn ging ng Vit Nam t

c nhng thnh tu kh ng k, t nm 1991 n nay c trn 20 gingng lai c cc nh khoa hc Vit Nam chn to ra v c trng ph bin

trong sn xut. Mt s ging ng lai tiu biu l LVN1, LVN5, LVN22,

LVN17 (thuc nhm chn trung bnh) v cc ging thuc nhm di ngy l

LVN10, LVN16, LVN19 (Nguyn Th hng, 2003)[10]

Ngoi ra, cn mt s ging ng lai khng quy c v quy c ca Vin

khoa hc Nng nghip min nam. Cng ty ging cy trng min Nam v mt

s ging ca cc cng ty ging cy trng nc ngoi nhcng ty Pacific vi

ging ng P11, P60, Tp on CP vi ging DK888, DK999, Cng ty Pioneer

vi ging P3011, P3012, Cng ty Bioseed vi ging B9670, B9681, Cng ty

Novatis... Bn cnh nhng nghin cu v to ging th nhng nghin cu v

k tht nng hc, cng ngh sau thu hoch cng c tin hnh song song

nh: Phn bn, phng tr su bnh c cu ma v..v.v.... Vic t chc sn


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xut, chuyn giao cng ngh ht ging ng lai c tin hnh trn phm vi

ton quc (Nguyn Th Hng, 2003)[10]

Mt hng mi trong nghin cu ng l chn to cc ging ng c hmlng Protein cao (Ng QPM). Chu hin nay c ba quc gia c chng

trnh nghin cu v pht trin ng giu m cht lng cao l: Trung Quc,

n v Vit Nam. Vin nghin cu v pht trin ng QPM. Nm 2002,

ging ng u tin c cng nhn khu vc ho rng trn ton quc l ging

ng lai n HQ 2000.


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3. Ni dung v phng php nghin cu

3.1. Ni dung nghin cu

3.1.1.nh gi kh nng phi hp ca 32 dng da trn th nghim so

snh cc t hp lai trng trong v Thu ng 2004.

3.1.2. nh gi kh nng phi hp ca 11dng c nng sut cao c la

chn t th nghim1 trng v ng xun 2005.

3.2. Phng php nghin cu

3.2.1. a im nghin cu

- Trung tm chuyn giao khoa hc k thut cng ngh cao Vin Di

truyn Nngnghip : Vn giang - Hng yn.

- Cnh ng s 3, trng i hc nng nghip I : Gia lm - H ni.

3.2.2. Vt liu nghin cu

- Vt liu trong th nghim l con lai ca 64 t hp lai. Cc t hp lai

c to ra t : 18 dng t phi, 3 dng Full-sib, 11 dng Half-sib v 2tester

(ging th phn t do). Cc dng th kh nng kt hp qua nh gi nng

sut, kh nng chng chu t cc v trc.

- S dng ging ng a phng S12 lm i chng, c 10 t hp c

mt i chng.

- Th nghim s dng vt tv cc bin php k thut c bn trong k

thut trng ng.


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* Cc dng tham gia th nghim

Dng Hafl-sib Dng t phi

STT Khiu dng Tn gc 1 S1INL2

1 HNXS12-3 2 S1INL2-2

2 HNXS12-1 3 S1INL2-3

S1: Ng np

nng

3 HNXS12-8

S12: Np trng

N Xc

4 S7IMP3

4 HBS14-2 S14: Np trng 5 S7IMP1

5 HNTS11 6 S7IMP1-2 S7: Ng np

6 HNTS11-1 7 S10IB1

7 HNT1S11

S11: Np trng 2

8 S10IB1-1

8 HMLS1-1 9 S10IB1-2

9 HMLS1-2

S1: Ng np

nng 10 S10IB1-3

10 HNXS6-1 11 S10IB212 S10IB2-111 HNXS6-2-2

S6: Khu LmLm

13 S10IB2-2

Dng Full-sib 14 S10IB2-3

1 FNTS6-2 15 S10IB2-4

2 FNTS6-4 16 S10IB2-5

S10: Pu

Cm Lu

(ng np)

17 S12INX33 FNTS6-5

18 S12INX3-1

S12: Np

trng N

Xc

Tester

1 Khu li 2 Pu c ru


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* Cc t hp lai s dng trong th nghim 1:

STT THL STT THL

1 S1INL2 x Pu c ru 33 S1INL2 x Khu li 2 S1INL2-2 x Pu c ru 34 S1INL2-2 x Khu li 3 S1INL2-3 x Pu c ru 35 S1INL2-3 x Khu li 4 S7IMP3 x Pu c ru 36 S7IMP3 x Khu li 5 S7IMP1 x Pu c ru 37 S7IMP1 x Khu li 6 S7IMP1-2 x Pu c ru 38 S7IMP1-2 x Khu li 7 S10IB1 x Pu c ru 39 S10IB1 x Khu li 8 S10IB1-1 x Pu c ru 40 S10IB1-1 x Khu li 9 S10IB1-2 x Pu c ru 41 S10IB1-2 x Khu li

10 S10IB1-3 x Pu c ru 42 S10IB1-3 x Khuli 11 S10IB2 x Pu c ru 43 S10IB2 x Khuli 12 S10IB2-1 x Pu c ru 44 S10IB2-1 x Khuli 13 S10IB2-2 x Pu c ru 45 S10IB2-2 x Khuli 14 S10IB2-3 x Pu c ru 46 S10IB2-3 x Khuli 15 S10IB2-4 x Pu c ru 47 S10IB2-4 x Khuli 16 S10IB2-5 x Pu c ru 48 S10IB2-5 x Khuli 17 S12INX3 x Pu c ru 49 S12INX3 x Khuli 18 S12INX3-1 x Pu c ru 50 S12INX3-1 x Khuli 19 FNTS6-2 x Pu c ru 51 FNTS6-2 x Khuli 20 FNTS6-4 x Pu c ru 52 FNTS6-4 x Khuli 21 FNTS6-5 x Pu c ru 53 FNTS6-5 x Khuli 22 HNXS12-1 x Pu c ru 54 HNXS12-1 x Khuli 23 HNXS12-8 x Pu c ru 55 HNXS12-8 x Khuli 24 HNXS6-1 x Pu c ru 56 HNXS6-1 x Khuli 25 HNXS6-2-2 x Pu c ru 57 HNXS6-2-2 x Khuli 26 HNXS12-3 x Pu c ru 58 HNXS12-3 x Khuli

27 HBS14-2 x Pu c ru 59 HBS14-2 x Khuli 28 HNTS11 x Pu c ru 60 HNTS11 x Khuli 29 HNT1S11 x Pu c ru 61 HNT1S11 x Khuli 30 HMLS11-1 x Pu c ru 62 HMLS11-1 x Khuli 31 HMLS11-2 x Pu c ru 63 HMLS11-2 x Khuli 32 HMLS11-3 x Pu c ru 64 HMLS11-3 x Khuli C S12


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* Cc t hp lai s dng trong th nghim 2:

STT THL

1 S1INL2 x Pu c ru

2 S1INL2 x Khu li

3 S7IMP1 x Pu c ru

4 S7IMP1 x Khu li

5 S10IB1 x Pu c ru

6 S10IB1 x Khu li

7 S10IB1-2 x Pu c ru

8 S10IB1-2 x Khu li


10 S10IB1-3 x Khuli

11 S10IB2 x Pu c ru

12 S10IB2 x Khuli


14 S10IB2-1 x Khuli

15 FNTS6-2 x Pu c ru

16 FNTS6-2 x Khuli

17 FNTS6-5 x Pu c ru

18 FNTS6-5 x Khuli

19 HNXS6-2-2 x Pu c ru20 HNXS6-2-2 x Khuli

21 HBS14-2 x Khuli

22 HBS14-2 x Pu c ru

23 S12(/C)


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3.2.3. Phng php b tr th nghim

- Th nghim 1 bao gm 64 t hp v mt i chng (S12). Tng din

tch th nghim l 1520m2 trong hng bo v l: 1m x 80m = 80m 2. Cc

th nghim c kch thc 2,5m x 4m x144 = 1440m2

- Th nghim 2 bao gm 25 t hp thc hin lai th nghim 1 v

mt i chng (S12). Tng din tch th nghim l 580 m2 trong hng bo

v l: 1m x 40m = 40m2. Cc th nghim c kch thc 2,5m x 4m x 54 =

540 m2.

- Hai th nghim trin khai l loi th nghim mt nhn t c b tr

theo kiu khi ngu nhin y (CRD), gm hai ln nhc li.

3.2.4. Cc bin php k thut c p dng

3.2.4.1. Thi v

- Th nghim 1 c tin hnh trong v Thu ng (Gieo 1/ 9/2004)

- Th nghim 2 c tin hnh trong v ng xun (Gieo 24/ 2/2005).

3.2.4.2. Lm t, gieo ht

t c cy su 25 - 30cm, phay nh, ba bng, nht sch c. Dng

dy chia thnh th nghim theo kch thc c nh sn.

Rch hng theo khong cch : 70 x 25cm, tng ng vi mt

50000cy/ha. Ht trc gieo c ngm nc, sau gieo lp t su 3 - 4cm.

3.2.4.3. Chm sc

* Phn bn:

+ Lng phn bn/ha:

5000kg phn chung + 500kg vi bt + 120kg N + 90kgP2O5+ 60kg K2O.

+ K thut bn:


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- Bn lt: 100% (phn chung, vi bt, P2O5) tin hnh sau khi rch

hng ri lp t, trc gieo ht.

- Bn thc: 3 ln

Ln 1: Khi cy c 3 - 4 l tht vi lng phn : 1/3N + 1/2K2O.

Ln 2: Khi cy c 7 - 9 l tht, bn 1/3N.

Ln3 : Khi cy son ln, bn lng phn cn li.

* Ta nh cy, lm c, xi xo vun t, ti nc:

+ Lm c, xi ph vng, vun nh kt hp vi bn phn khi cy t 3 - 4

l tht.

+ Ta nh cy khi cy t 4 - 5 l tht.

+ Lm c, bn phn, vun gc khi cy t 7 - 9 l tht.

+ Xi, vun cao ln cui khi cy xon ln (trc tr 15 ngy)

+ Ti nc gi m thng xuyn, c bit thi k cy con v tr c.

* Phng tr su bnh:

c tin hnh thng xuyn trong sut giai on sinh trng ca cy,

quan st pht hin c bin php phng tr kp thi v hiu qu nht.

* Thu hoch: Tin hnh thu ring tng cp lai khi l bi kh.

3.2.5. Cc ch tiu v phng php theo di

3.2.5.1. Ch tiu sinh trng

+ Ngy gieo.

+ Ngy mc.

+ Ngy tung phn (Khi c >50% s cy tung phn).

+ Ngy phun ru (Khi c >50% s cy phun ru).

+ Ngy chn sinh l khi chn ht c chm en hoc khong 75% cy c

l bi kh.


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3.2.5.2. Cc ch tiu hnh thi

+ Chiu cao cy cui cng: c tnh sau tr 15 ngy. o t mt t ti

t phn nhnh c u tin.+ Chiu cao ng bp: Tnh t gc n bp u tin.

+ S l: Tnh t l tht th nht n l cui cng.

+ S bp/cy.

+ Chiu di bp: Tnh t gc bp n ngn bp (khng k l bi).

+ ng knh bp: Tnh cch gc bp 1/3.

3.2.5.3. Ch tiu nng sut

+ S bp hu hiu

+ S hng ht/bp (Hng ht c tnh khi c 50% s ht so vi hng

di nht)

+ S ht/hng (c m cho hng c chiu di trung bnh)

+ Khi lng 1000ht ( m 14%): Cn 2 mu mi mu 500 ht nu

chnh lch nhau khng qu 5% l chp nhn nu khng c th m thm

mu th 3.+ Nng sut c th

+ Nng sut l thuyt c tnh theo cng thc

S bp hu hiu/cy x S ht/bp x S ht/hng x t l ht/bp x P1000 ht x 50000NSLT =

100.000.000

+ Nng sut thc thu (NSTT) m 14% cc tnh theo cng thc

(100-A0) 10.000NSTT = P bp ti x t l ht trn bp x100-14)

xSo

Trong :

Ao: l m ht khi thu hoch

So: l din tch th nghim

14%: l m ht bo qun


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3.2.5.4. Kh nng chng chu

+ Kh nng chng chu su bnh

- Su c thn (%): m s cy c thn trn 1 th nghim. Theo

di giai on t 7-8 l tht v giai on chn sa sau tnh t l.

- Bnh kh vn, m l: tnh t l v cho im t 1-5 xc nh

t l b bnh.

im 1: Khng b hoc b rt t.

im 2: Khong 20 30% s l b bnh.

im 3: Khong 40 60% s l b bnh.im 4: Khong 70 90% s l b bnh.

im 5: Khong 100% s l b bnh.

+ Kh nng chng

Xc nh t l cy (cy nghing mt gc >300so vi phng thng

ng) trn tng s cy th nghim.

3.3. Phng php thu thp v x l s liu

+ Cc s liu c thu thp trong qu trnh chm sc v theo di thnghim bng cch nh du cy v o m.

+ Tnh cc gi trung bnh v mt s thng k c bn bng phn mm Excel.

+ Phn tch KNKH chung ca cc dng tham gia cc t hp lai trn c

s ch tiu nng sut bng chng trnh phn tch phng sai Line Tester

(Ver.2.0- Nguyn nh Hin, 1995).


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4. Kt qu nghin cu v tho lun

A.Th nghim 1

Xc nh KNKH ca 64 THL c to ra t 32 dng ng a phng,

trong v Thu ng 2004

4.1. c im sinh trng ca cc THL

4.1.1. Cc giai on sinh trng ca cc THL

Thi gian sinh trng ca cy ng c tnh t khi gieo ht n khi ht

chn sinh l, y l c s cc nh nghin cu chia thnh 3 nhm ging ng

chnh l nhm chn sm, chn trung bnh v chn mun. Tuy nhin thi

gian ny khng c nh m bin ng theo ging, theo ma v v cc vng

sinh thi khc nhau.

Vic theo di qu trnh sinh trng, pht trin ca cc THL l c s

gip ta b tr thi v v c cu lun canh cy trng hp l. iu cn c

ngha trong vic la chn v phn vng sinh thi cho cc ging ng, ph hp

vi iu kin thi tit kh hu ca tng vng khc nhau. Kt qu theo di th

nghim c th hin qua bng 4.1a.


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Bng 4.1a: Cc giai on sinh trng ca cc THL

Bng 4.1a.1. Vi cy th Khulo

VT: Ngy

STT THLGieo-mc

Gieotungphn

Gieo-phunru

Chnhlch

TP-PR

Gieo-chn

sinh l

1 S1INL2 x Khu li 3 56 58 2 953 S1INL2-2 x Khu li 4 62 64 2 1065 S1INL2-3 x Khu li 3 65 65 0 1017 S7IMP3 x Khu li 4 55 58 3 989 S7IMP1 x Khu li 4 62 65 3 105

11 S7IMP1-2 x Khu li 4 60 63 3 9513 S10IB1 x Khu li 4 57 62 2 9715 S10IB1-1 x Khu li 4 56 56 0 10317 S10IB1-2 x Khu li 3 60 61 1 9619 S10IB1-3 x Khuli 3 60 60 0 9821 S10IB2 x Khuli 3 58 60 2 10623 S10IB2-1 x Khuli 4 55 56 1 9825 S10IB2-2 x Khuli 3 52 54 2 10027 S10IB2-3 x Khuli 4 64 66 2 10529 S10IB2-4 x Khuli 4 56 58 2 9831 S10IB2-5 x Khuli 3 56 59 3 9533 S12INX3 x Khuli 4 54 56 2 9835 S12INX3-1 x Khuli 4 61 61 0 10037 FNTS6-2 x Khuli 3 53 56 3 9539 FNTS6-4 x Khuli 3 53 56 3 10041 FNTS6-5 x Khuli 4 58 59 1 10043 HNXS12-1 x Khuli 3 56 57 1 9545 HNXS12-8 x Khuli 3 59 62 3 9847 HNXS6-1 x Khuli 4 55 57 2 98

49 HNXS6-2-2 x Khuli 4 65 66 1 10551 HNXS12-3 x Khuli 3 52 54 2 10053 HBS14-2 x Khuli 4 54 56 2 9555 HNTS11 x Khuli 3 62 64 2 9857 HNT1S11 x Khuli 4 61 64 3 9859 HMLS11-1 x Khuli 3 52 52 0 10261 HMLS11-2 x Khuli 3 55 57 2 9563 HMLS11-3 x Khuli 3 53 54 1 9565 S12 3 56 59 3 97


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Bng 4.1a.2 Vi cy th Pucru

VT: Ngy

STT THL

Gieo-

mc

Gieo-

tungphn

Gieo-

phunru

Chnhlch

TP- PR

Gieo-

chnsinh l

2 S1INL2 x Pu c ru 4 63 63 0 984 S1INL2-2 x Pu c ru 4 61 64 3 1006 S1INL2-3 x Pu c ru 3 65 65 0 978 S7IMP3 x Pu c ru 3 53 57 4 95

10 S7IMP1 x Pu c ru 4 55 55 0 9512 S7IMP1-2 x Pu c ru 4 59 60 1 103

14 S10IB1 x Pu c ru 4 53 55 2 9516 S10IB1-1 x Pu c ru 4 60 60 0 9818 S10IB1-2 x Pu c ru 3 58 58 0 9520 S10IB1-3 x Pu c ru 4 59 60 1 9322 S10IB2 x Pu c ru 4 58 61 3 9524 S10IB2-1 x Pu c ru 4 60 62 2 9826 S10IB2-2 x Pu c ru 3 62 62 1 9828 S10IB2-3 x Pu c ru 3 52 54 2 10530 S10IB2-4 x Pu c ru 3 55 56 1 95

32 S10IB2-5 x Pu c ru 3 55 57 2 9834 S12INX3 x Pu c ru 4 57 58 1 10536 S12INX3-1 x Pu c ru 3 56 57 1 10538 FNTS6-2 x Pu c ru 4 55 57 2 9840 FNTS6-4 x Pu c ru 4 57 57 0 9842 FNTS6-5 x Pu c ru 3 54 56 2 9544 HNXS12-1 x Pu c ru 3 58 59 1 10346 HNXS12-8 x Pu c ru 4 57 59 2 9548 HNXS6-1 x Pu c ru 4 62 63 1 10150 HNXS6-2-2 x Pu c ru 3 52 53 1 9852 HNXS12-3 x Pu c ru 4 56 59 3 9854 HBS14-2 x Pu c ru 4 55 58 3 9556 HNTS11 x Pu c ru 4 65 66 1 10058 HNT1S11 x Pu c ru 4 57 60 3 9560 HMLS11-1 x Pu c ru 3 58 59 1 10062 HMLS11-2 x Pu c ru 4 63 66 3 10064 HMLS11-3 x Pu c ru 4 56 59 3 9865 S12 3 56 59 3 97


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* Giai on t gieo n mc

Giai on t gieo n mc l giai on u tin ca chu k sinh trng,

pht trin. Giai on ny rt quan trng i vi cy ng, n quyt nh ch

yu n s sinh trng, pht trin sau ny, m bo s cy trn n v din

tch v quyt nh n nng sut qun th rung ng.

Qu trnh ny mm din ra nhanh hay chm c th hin bng thi gian

t gieo n mc ca cc dng, ging. Nhng ging khc nhau th thi gian

mc khc nhau. Thng thng nhng ging c cht lng tt, ht to th thi

gian mc nhanh, v t l mc cao v ngc li. Tuy nhin qu trnh ny mmcn chu tc ng ca iu kin ngoi cnh nhm v nhit Nhit

v m thch hp cho cc dng ging cao, th tc mc ca cc dng

ging nhanh v thun li cho cy pht trin tt.

Qua theo di chng ti thy giai on ny mm ca cc THL trong th

nghim bin ng khng ln t 3 - 4 ngy v tng tng vi i chng, iu

ny chng t cht lng ht ging tng i tt, ng u v thi tit kh huca giai on ny ph hp cho s ny mm ca ht.

* Giai on t gieo n tung phn

Giai on tung phn din ra trong khong thi gian khng di, trung bnh

t 10-16 ngy, nhng y l giai on quyt nh n nng sut.

Khi bc vo giai on xon nn (trc tr c tung phn 7-10 ngy) cy

ng yu cu iu kin ngoi cnh kht khe. Trong khi tin hnh th nghimchng ti thy iu kin ngoi cnh (nhit , m ) trong thng 10 nm

2004 ti Vn Giang Hng Yn tng i thun li cho cy ng tung phn.

Theo kt qu bng 4.1a cho thy: Thi gian t gieo n tung phn ca cc

THL bin ng trong khong 52 - 65 ngy. Trong 5 THL l : 25, 28, 50,

51, 59 (52 ngy) tung phn sm nht, tip n l THL 8, 14, 37, 39, 63 (53


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ngy), v cui cng l THL 5, 6, 49, 56 (65 ngy) tung phn mun nht.

* Giai on t gieo n phun ru

Giai on t gieo n phun ru l thi k quan trng n lin quan n

kh nng nhn phn v nh hng trc tip n nng sut ca cy ng sau

ny. Qua bng 4.1 chng ti thy cc THL c khong thi gian t gieo n

phun ru l 51 - 66 ngy. Trong THL : 49, 56, 62 phun ru mun nht (66

ngy), THL 50 phun ru sm nht (51 ngy).

* Chnh lch thi gian gia tung phn v phun ru

Thi gian tung phn v phun ru c s chnh lch cc THL. S chnh

lch ny ph thuc vo tng dng, ging v khc nhau cc thi v, iu kin

ngoi cnh. Nu THL no c gi tr chnh lch cng nh th lng phn tham

gia vo qu trnh th phn th tinh cng ln, dn n kh nng kt ht v cho

nng sut cao. Ch tiu ny cng c chng t Genotypes n nh v mt di

truyn qua cc mi trng khc nhau. Qua bng 4.1a cho thy cc THL c

thi gian chnh lch t tung phn n phun ru t 0- 4 ngy, khong thi gianny thp i vi cc dng fullsib v hafl- sib (0- 3 ngy) cao i vi dng t

phi (0- 4 ngy). Trong THL s 2, 5, 6, 15, 16, 18, 19, 35, 40, 59 c thi

gian tung phn v phun ru trng nhau, THL 8 chnh lch tung phn, phun ru

4 ngy.

* Giai on t gieo n chn sinh l

Qua bng 4.1a chng ti thy thi gian t gieo n chn sinh l ca cc

THL bin ng t 93-106 ngy, THL 20 c thi gian sinh trng ngn nht

(93 ngy) v di nht l THL 21 (106 ngy).

Vic theo di thi gian sinh trng, pht trin ca cc THL l c s

quan trng gip ta b tr thi v trong sn xut ht lai vi cc THL c trin

vng. ng thi n cn c ngha quan trng trong vic la chn v phn


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vng sinh thi cho cc ging ng sao cho ph hp vi iu kin ca mi vng.

4.1.2. Tc tng trng chiu cao cy

cc giai on sinh trng khc nhau, tc tng trng chiu cao

cy ca cc THLl khc nhau. Thng thng chiu cao cy giai on u

tng dn sau gim v n giai on tr c th tng vt ri dng li.

Tc tng trng chiu cao cy ca cc THL v thu ng nm 2004

ti Vn giang Hng yn c trnh by bng 4.2a.

Qua bng 4.2a cho thy chiu cao cy ca cc THL trong 3 tun utng dn, trong tun u tin tng trung bnh 14,21cm/tun, tun th 2 tng

17,27 cm/tun, tun th 3 tng 26,35 cm/tun. n tun th 4(26/9-2/10) tc

tng trng chiu cao cy c xu hng gim so vi tun th 3 v t trung

bnh 20,89 cm/tun. Trong THL s 8(28,32cm/tun) c tc tng trng

chiu cao cy cao nht cao hn so vi ging i chng S12(24,00 cm/tun) l

4,32cm, t hp lai 13(14,00 cm/tun) tng chm nht. Bc sang tun th 5

(2/10-9/10) chiu cao cy ca cc THL tng nhanh t trung bnh 36,24 cm/

tun. y l giai on a s THL bc vo thi k vn lng v pht trin s

l mnh. tun ny THL 46 c tc tng trng cao nht t 48,16

cm/tun cao hn so vi ging i chng S12 l 30,86 cm/tun, THL 15(22,72

cm/tun) tng chm nht. Vo tun th su bn cnh mt s THL tr bng

c cn cc THL khc vn tip tc tng chiu cao v t trung bnh 21,21 cm

/tun. THL s 31(58,34cm /tun) c tc tng trng chiu cao cy mnhnht v thp nht l THL 38 (31,26 cm/tun).


62/118

Bng 4.2a : Tc tng trng chiu cao cy ca cc THL

Bng 4.2a.1 Vi cy th Khulo

VT: Cm/7Ngy

STT THL5/9-12/9

12/9-19/9

19/9-26/9

26/9-2/10

2/10-9/10

9/10-16/10

Caocy

1 S1INL2 x Khu li 9.42 14.98 23.36 18.92 31.98 55.72 205,53 S1INL2-2 x Khu li 17.16 19.76 20.08 19.96 37.62 46.50 205,75 S1INL2-3 x Khu li 24.40 21.52 27.60 21.38 41.44 50.84 200,57 S7IMP3 x Khu li 17.98 20.84 27.78 21.54 40.48 57.86 215,89 S7IMP1 x Khu li 18.10 18.94 30.38 24.36 41.22 43.42 198,6

11 S7IMP1-2 x Khu li 16.64 19.52 21.78 19.84 37.92 49.62 197,913

S10IB1 x Khu li 13.30 17.06 23.22 14.00 29.86 39.62 190,315 S10IB1-1 x Khu li 13.68 13.96 21.14 17.62 22.72 46.16 200,817 S10IB1-2 x Khu li 11.12 16.12 24.26 15.04 34.20 49.20 220,319 S10IB1-3 x Khuli 24.72 23.42 32.14 27.74 37.70 41.20 200,421 S10IB2 x Khuli 20.58 19.44 28.28 21.14 41.80 53.16 220,323 S10IB2-1 x Khuli 13.34 14.80 26.92 19.28 38.18 50.94 217,925 S10IB2-2 x Khuli 16.00 16.68 32.84 26.28 39.40 50.42 217,727 S10IB2-3 x Khuli 12.30 27.12 37.06 20.48 38.34 40.78 200,829 S10IB2-4 x Khuli 14.60 16.16 27.38 25.16 34.00 35.56 195,031 S10IB2-5 x Khuli 15.40 21.16 26.38 21.72 37.76 58.34 215,633 S12INX3 x Khuli 11.02 15.92 23.32 19.70 42.36 30.46 225,635 S12INX3-1 x Khuli 10.96 17.80 21.26 17.68 31.50 34.58 225,737 FNTS6-2 x Khuli 15.30 20.00 24.74 20.96 37.16 32.70 202,439 FNTS6-4 x Khuli 12.68 24.22 26.26 24.56 40.80 47.60 219,841 FNTS6-5 x Khuli 11.86 13.10 21.72 17.58 37.92 40.04 187,743 HNXS12-1 x Khuli 15.86 16.62 21.66 14.84 26.34 32.92 217,845 HNXS12-8 x Khuli 13.18 16.96 24.46 16.28 24.76 34.88 218,147 HNXS6-1 x Khuli 10.76 14.28 23.10 18.72 31.84 47.46 219,749 HNXS6-2-2 x Khuli 15.30 20.00 24.74 20.96 37.16 42.70 194,351 HNXS12-3 x Khuli 9.74 10.48 30.74 23.82 36.66 40.96 223,453 HBS14-2 x Khuli 12.64 16.50 25.54 18.82 32.86 36.10 202,555 HNTS11 x Khuli 17.96 17.88 24.70 22.48 31.50 43.38 198,657 HNT1S11 x Khuli 10.14 8.78 25.46 22.46 35.96 45.12 195,359 HMLS11-1 x Khuli 18.46 17.64 23.48 15.04 30.84 46.30 197,161 HMLS11-2 x Khuli 14.48 18.52 27.96 22.96 38.40 45.76 185,263 HMLS11-3 x Khuli 10.94 13.34 28.56 15.72 31.86 37.26 179,765 S12 12.30 17.06 23.22 24.00 30.86 39.62 123,5


63/118


VT: Cm/7Ngy

STT THL5/9-12/9

12/9-19/9

19/9-26/9

26/9-2/10

2/10-9/10

9/10-16/10

Caocy

2 S1INL2 x Pu c ru 14.30 15.58 29.98 20.30 37.08 56.14 220,44 S1INL2-2 x Pu c ru 21.00 17.56 19.72 18.82 36.12 53.70 210,36 S1INL2-3 x Pu c ru 17.50 19.38 35.30 28.32 38.94 53.40 210,58 S7IMP3 x Pu c ru 15.16 21.08 27.86 21.80 37.58 51.64 210,3

10 S7IMP1 x Pu c ru 22.48 23.92 29.76 25.10 38.00 41.54 196,612 S7IMP1-2 x Pu c ru 14.58 19.78 20.62 18.72 36.76 55.00 197,6

14 S10IB1 x Pu c ru 10.74 13.78 24.64 17.76 31.46 51.98 213,516 S10IB1-1 x Pu c ru 12.18 14.64 24.46 18.52 35.52 52.20 220,118 S10IB1-2 x Pu c ru 11.12 12.98 21.36 16.96 32.34 49.04 213,720 S10IB1-3 x Pu c ru 17.90 21.68 39.94 24.38 38.14 52.52 223,422 S10IB2 x Pu c ru 19.66 18.78 30.66 24.40 45.38 47.30 217,624 S10IB2-1 x Pu c ru 12.16 15.52 28.08 21.32 41.92 50.46 211,226 S10IB2-2 x Pu c ru 16.68 18.26 26.88 21.70 34.36 52.10 214,628 S10IB2-3 x Pu c ru 14.58 19.14 28.52 23.86 33.34 37.14 198,830 S10IB2-4 x Pu c ru 11.14 18.16 19.74 25.14 33.98 36.28 215,232 S10IB2-5 x Pu c ru 14.36 15.14 25.58 19.82 39.92 200,734 S12INX3 x Pu c ru 12.56 13.58 22.32 22.70 35.64 33.58 185,136 S12INX3-1 x Pu c ru 10.40 14.28 28.86 26.02 38.42 49.82 223,638 FNTS6-2 x Pu c ru 13.74 21.14 26.78 22.88 33.88 31.26 193,540 FNTS6-4 x Pu c ru 10.96 23.84 29.34 26.10 40.28 45.58 214,742 FNTS6-5 x Pu c ru 10.06 11.42 24.96 19.40 34.82 49.46 223,144 HNXS12-1 x Pu c ru 16.84 12.64 20.68 14.46 31.32 40.32 223,246 HNXS12-8 x Pu c ru 11.04 18.68 29.12 25.18 48.16 56.12 229,548 HNXS6-1 x Pu c ru 14.34 19.28 26.44 19.10 43.64 42.96 205,650 HNXS6-2-2 xPu c ru 13.74 21.14 26.78 22.88 43.88 41.26 197,552 HNXS12-3 x Pu c ru 8.22 10.92 20.34 16.86 36.86 37.42 215,254 HBS14-2 x Pu c ru 11.82 16.52 28.28 19.54 43.34 50.38 217,956 HNTS11 x Pu c ru 11.18 14.06 35.80 18.02 38.94 37.52 213,258 HNT1S11 x Pu c ru 12.52 10.10 25.54 20.88 30.72 49.74 194,560 HMLS11-1 x Pu c ru 13.67 17.62 32.06 28.48 42.52 53.80 207,662 HMLS11-2 x Pu c ru 13.96 18.72 25.70 21.78 28.48 38.62 181,264 HMLS11-3 x Pu c ru 10.82 13.00 25.20 16.08 30.98 43.26 189,565 S12 12.30 17.06 23.22 24.00 30.86 39.62 123,5


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4.1.3. Tc tng trng s l

Tc tng trng s l ca THL trong th nghim 4 tun u tng

chm hn hai tun tip theo.

Tun u tin (5/9-12/9) tc ra l ca cc THL t trung bnh 1,42

l/tun, THL 6 c tc ra l ln nht t 2,4 l/tun cao hn S12 (0,90

l/tun) l 1,5 l. THL s 6, 47, 48, 55, 60, 64 tc ra l t thp nht 0,8 l

/tun. Tun th hai (12/9 19/9) v tun th 3(19/9 26/9) tc ra l trung

bnh ca cc t hp lai t 1,57 l/tun, trong THL 6 c tc ra l cao

nht t 2 l /tun (tun 2), THL 54 t 2,4 l/tun (tun th 3) cao hn i

chng S12 l 0,7 l. Cn THL 13,41 c tc ra l thp nht t 1l/tun.

Tip n tun th t(26/9 2/10) tc ra l ca trung bnh ca cc t hp

lai t 1,21 cao hn S12 l 0,1 l/tun, THL s 35 c tc ra l ln nht t

2,4 l/tun, chm nht t 0,6 l/tun l THL 20, 29.

Chuyn sang tun th 5(2/10 9/10) c bit l tun th 6(9/10 16/10) tc ra l ca cc THL tng rt nhanh bi y l giai on cy vn

lng mnh ko theo l cng tng vt. Tc ra l tun th 5 t trung bnh

2,17 l /tun, THL 51 c tc tng trng s l cao nht t 3,4 l /tun cao

hn i chng S12(2,7 l /tun) l 0,7 l/tun, tip n l THL35(3,2 l /

tun), thp nht l THL 3,16,58 t 1,4 l/tun. tun th 6 tc ra l trung

bnh ca cc THL t 3,38 l /tun, cao nht l THL 21,45,46,47,61(4,6l/tun), thp nht l THL 57,58(2,4 l/tun)

Qua bng 4.3a chng ti thy cc THL c thi gian sinh trng ngn th

tc ra l gim tun th 4 v tng cao tun th 5, cn cc THL c thi

gian sinh trng di hn th tc ra l n tun th 5 tng chm v tng

nhanh nht tun th 6.


65/118

Bng 4.3a: Tc tng trng s l ca cc THL

Bng 4.3a.1 Vi cy th KhuloVT: L/7Ngy

Thi gian theo distt THL 5/9-

12/912/9-19/9

19/9-26/9

26/9-2/10

2/10-9/10

9/10-16/10

1 S1INL2 x Khu li 2.20 1.40 1.60 1.00 2.00 3.003 S1INL2-2 x Khu li 1.60 1.00 1.80 1.40 1.40 3.605 S1INL2-3 x Khu li 1.40 1.40 1.80 1.20 2.20 3.407 S7IMP3 x Khu li 1.00 1.40 1.40 1.20 2.00 3.40

9 S7IMP1 x Khu li 1.40 1.40 1.20 1.40 2.00 2.6011 S7IMP1-2 x Khu li 1.40 1.20 2.00 1.00 2.20 2.8013 S10IB1 x Khu li 1.40 1.60 1.00 1.00 2.20 3.4015 S10IB1-1 x Khu li 1.60 1.40 1.80 1.20 1.80 3.4017 S10IB1-2 x Khu li 1.20 1.60 1.40 1.00 1.80 3.4019 S10IB1-3 x Khuli 1.20 1.20 1.60 1.00 2.20 4.0021 S10IB2 x Khuli 1.80 1.40 1.80 1.20 2.20 4.2023 S10IB2-1 x Khuli 2.00 1.20 1.60 0.60 2.00 4.0025 S10IB2-2 x Khuli 1.60 1.00 1.80 1.00 2.60 3.40

27 S10IB2-3 x Khuli 1.60 1.40 1.00 1.40 1.80 3.0029 S10IB2-4 x Khuli 2.20 1.40 1.60 0.60 2.00 3.0031 S10IB2-5 x Khuli 1.40 1.60 1.40 1.20 2.40 3.8033 S12INX3 x Khuli 1.60 1.20 2.00 1.00 2.20 3.4035 S12INX3-1 x Khuli 1.60 1.60 2.00 2.40 3.20 3.8037 FNTS6-2 x Khuli 0.40 1.60 1.60 1.00 2.20 2.8039 FNTS6-4 x Khuli 2.20 1.00 1.60 1.00 1.80 3.0041 FNTS6-5 x Khuli 1.80 1.00 1.60 1.00 1.60 2.6043 HNXS12-1 x Khuli 1.40 1.80 1.20 1.20 2.20 2.80

45 HNXS12-8 x Khuli 1.00 1.60 1.40 1.80 2.60 4.6047 HNXS6-1 x Khuli 0.80 1.60 1.60 1.40 1.80 4.6049 HNXS6-2-2 x Khuli 1.40 1.60 2.00 1.60 2.80 4.1051 HNXS12-3 x Khuli 2.20 1.60 2.20 1.40 3.40 3.6053 HBS14-2 x Khuli 1.00 1.80 2.20 1.00 2.80 3.8055 HNTS11 x Khuli 0.80 1.60 1.60 1.00 2.20 2.6057 HNT1S11 x Khuli 1.20 1.40 1.80 1.30 2.00 2.4059 HMLS11-1 x Khuli 1.00 1.40 1.20 1.20 2.00 3.4061 HMLS11-2 x Khuli 1.20 1.60 1.20 1.20 2.20 4.20


66/118

63 HMLS11-3 x Khuli 1.00 1.80 1.80 1.40 2.00 3.0065 S12 0.90 1.10 1.70 1.10 2.70 3.80


67/118


VT: L/7Ngy

Thi gian theo distt THL 5/9-12/9

12/9-19/9

19/9-26/9

26/9-2/10

2/10-9/10

9/10-16/10

2 S1INL2 x Pu c ru 1.20 2.00 1.80 1.00 1.80 3.004 S1INL2-2 x Pu c ru 1.40 1.60 1.40 1.00 2.00 3.006 S1INL2-3 x Pu c ru 1.60 1.60 1.40 1.00 2.20 3.608 S7IMP3 x Pu c ru 2.40 2.00 1.00 1.20 2.00 2.80

10 S7IMP1 x Pu c ru 1.60 1.80 1.70 1.00 2.40 2.8012 S7IMP1-2 x Pu c ru 2.00 1.60 1.40 1.00 2.00 3.20

14 S10IB1 x Pu c ru 1.60 1.40 1.20 1.40 2.00 2.8016 S10IB1-1 x Pu c ru 0.80 1.60 1.80 1.40 1.40 3.2018 S10IB1-2 x Pu c ru 1.60 1.60 1.60 0.80 1.80 3.4020 S10IB1-3 x Pu c ru 1.20 1.40 1.80 0.60 2.20 3.6022 S10IB2 x Pu c ru 1.80 1.20 1.60 1.40 2.00 3.0024 S10IB2-1 x Pu c ru 2.00 1.40 1.80 1.00 2.20 3.2026 S10IB2-2 x Pu c ru 1.60 1.20 1.40 1.20 2.00 3.8028 S10IB2-3 x Pu c ru 1.20 0.80 2.00 1.20 2.00 3.4030 S10IB2-4 x Pu c ru 2.00 1.40 1.40 1.40 2.00 3.40

32 S10IB2-5 x Pu c ru 1.80 1.40 1.60 1.20 2.00 3.0034 S12INX3 x Pu c ru 1.80 1.80 1.40 1.80 1.80 3.2036 S12INX3-1 x Pu c ru 2.20 1.00 1.20 1.80 2.80 4.0038 FNTS6-2 x Pu c ru 1.00 1.20 1.60 1.20 2.00 3.8040 FNTS6-4 x Pu c ru 1.40 1.60 1.20 1.60 1.80 3.2042 FNTS6-5 x Pu c ru 1.40 2.00 1.60 1.20 2.20 3.2044 HNXS12-1 x Pu c ru 1.20 1.60 0.80 1.40 2.00 3.1046 HNXS12-8 x Pu c ru 1.80 1.20 1.80 1.20 2.20 4.60

48 HNXS6-1 x Pu c ru 0.80 1.40 1.40 1.20 1.60 4.8050 HNXS6-2-2 x Pu c ru 1.40 1.60 1.60 1.20 2.80 4.0052 HNXS12-3 x Pu c ru 1.40 1.80 1.80 1.00 2.60 3.0054 HBS14-2 x Pu c ru 1.00 1.20 2.40 1.40 2.80 3.6056 HNTS11 x Pu c ru 1.20 1.40 1.40 1.20 1.80 3.4058 HNT1S11 x Pu c ru 1.20 1.20 1.60 2.00 1.40 2.4060 HMLS11-1 x Pu c ru 0.80 1.60 1.20 1.20 2.60 3.0062 HMLS11-2 x Pu c ru 1.20 1.80 1.60 1.00 2.40 2.8064 HMLS11-3 x Pu c ru 0.80 2.00 1.80 0.80 2.60 3.40


68/118

65 S12 0.90 1.10 1.70 1.10 2.70 3.80


69/118

4.1.4. Chiu cao cui cng v chiu cao

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