Download pptx - Yam Physiology

Transcript
Page 1: Yam Physiology

Yam physiology

Key word: growth cycle, growth period varietal difference, senescence

Increasing the capacity of research technicians in breeding

28th July 2015

Ryo Matsumoto (visiting scientist from JIRCAS, Japan )

Page 2: Yam Physiology

1. Growth cycle of yam2. Development evaluation protocol for tuber

earliness/growth period3. Evaluation of tuber earliness characteristic4. Summary

Today’s topic

Page 3: Yam Physiology

Growth cycle of Yam

General

During the growth cycle, there are five distinct phases,

Page 4: Yam Physiology

Changing in dry weight of aerial and tuber part during growth cycle

Growth cycle of Yam

Jun Jul Aug Sep Oct Nov Dec0

100

200

300

400

500

600

700

800

Tuber weightAerial part weight

Dry

wei

ght (

g)

Page 5: Yam Physiology

Jun Jul Aug Sep Oct Nov Dec0

100

200

300

400

500

600

700

800

Tuber weightAerial part weight

Dry

wei

ght (

g)Growth cycle of Yam

Phase 1: Tuber germination • The stem is still devoid of expanded leaves, reducing the transpiring surface as much as possible to optimize the reserves for root development.

Page 6: Yam Physiology

Growth cycle of Yam

Phase 2: Foliage Development • Characterized by a very rapid and massive increase in leaf area and ends the dependence of the yam plant on the tuber sett.

• The plant reaches self-sufficiency (autotrophy)

Jun Jul Aug Sep Oct Nov Dec0

100

200

300

400

500

600

700

800

Tuber weightAerial part weight

Dry

wei

ght (

g)

Page 7: Yam Physiology

Growth cycle of Yam

Phase 3: Rapid Tuber bulking • Nutrient are translocated from canopy to tuber

• The more rapid is tuber development and the greater its final size.

Jun Jul Aug Sep Oct Nov Dec0

100

200

300

400

500

600

700

800

Tuber weightAerial part weight

Dry

wei

ght (

g)

Page 8: Yam Physiology

Growth cycle of Yam

Phase 4: Foliage senescence, tuber mature

Jun Jul Aug Sep Oct Nov Dec0

100

200

300

400

500

600

700

800

Tuber weightAerial part weight

Dry

wei

ght (

g)

Page 9: Yam Physiology

Development evaluation protocol for tuber earliness

Phase 5: Dormancy • Mature, freshly harvested tubers cannot sprout and they enter a dormancy phase which can last for leads than a month to up to 5 months.

Jun Jul Aug Sep Oct Nov Dec0

100

200

300

400

500

600

700

800

Tuber weightAerial part weight

Dry

wei

ght (

g)

Page 10: Yam Physiology

Jun Jul Aug Sep Oct Nov Dec0

100

200

300

400

500

600

700

800

Dry

wei

ght (

g)Five growth phase

Growth cycle of Yam

Phase 1 Phase 2 Phase 3 Phase 4 Phase 5

Page 11: Yam Physiology

Growth cycle of Yam

General

During the growth cycle, there are five distinct phases, which can vary according to growing condition, spices and genotype.Phase 1: Tuber germinationPhase 2: Foliage developmentPhase 3: Tuber bulkingPhase 4: Foliage senescence, tuber maturePhase 5: Dormancy

Page 12: Yam Physiology

Late mature varietyEarly mature variety

Varietal deference in tuber growth pattern of yam (White yam: D. rotundata)

Growth cycle of Yam

Days after planting

Tube

r mat

urity

rate

(%)

3 plants x 3 rep. x 6 times x 3 year rep. Aerial part:• Dry weight• Sprouting date• Senescence date

Tuber part:• Dry tuber weight

Early mature variety: Tuber growth stop earlier

Page 13: Yam Physiology

• Dispersion of risk at famer field (dry stress, insect attack at….)• Extension of period to provide fresh yam tuber at the materket• Expand yam growing area for food security

Growth cycle of Yam

Why do we need to get different growth period variety for famer and customer ??What is advantage point that farmer has different maturity variety ??

Page 14: Yam Physiology

• Rice   20 cm x 20 cm• Yam 100 cm x 100 cm

If you have to plan 100 seeds / seed tubers for experiment, how big field do you need ??

Rice: 400 cm2 (4 m2)Yam: 10000 cm2 (100m2)

New protocol which is simple and non-distractive for earliness evaluation were required

Questions !!!

Page 15: Yam Physiology

**Senescence indexSenescence index of aerial part is weekly recorded till surveyed plants each variety had completely been senescence. Senescence level is classified into the five levels and quantified.

Level 1 No senescence leaf ・・・ aLevel 2 25% senescence ・・・・・・ bLevel 3 50% senescence ・・・・・・ cLevel 4 70% senescence ・・・・・・ dLevel 5 100%senescence ・・・・・ e

Senescence index= {(1 ×No. of level 1 plant)+(2×No. of level 2 plant) + (3×No. of level 3 plant) + (4×No. of level 4 plant) + (5 ×No. of level 5 plant) / 9}

a b c d e

Development evaluation protocol for tuber earliness

Focus point: Senescence index

Page 16: Yam Physiology

After planting days

Sene

scen

ce in

dex

Late mature varietyEarly mature variety

Development evaluation protocol for tuber earliness

Start senescence aerial part,Early mature variety : 160 DAPLate mature variety :1 80 DAP

Changing in senescence index during growth period in early and late mature variety

Page 17: Yam Physiology

Days after planting

Senescence index

Relationship between tuber growth and senescence of aerial part

Tuber growth Senescence index

• Tuber growth finish• Photosynthesis finish• Start senescence of aerial part

Start senescence starting time was confirmed to be index parameter for earliness of tuber growth by plant physiologically staudy

Early mature variety: Tuber growth stop earlier Senescence of aerial part

also earlier

Development evaluation protocol for tuber earliness

Late mature varietyEarly mature variety

→ Non-distractive evaluation

Tube

r mat

urity

rate

(%)

Page 18: Yam Physiology

Evaluation of tuber earliness characteristic

Genetic resources (D. rotundata)

Genetic resources (447 lines as core collection) Diversity research set

(DRS-EDITS: 100 lines)

Smaller,But retain diversity

Experimental design• 3 plants• Randomized block design with 2 rep. Characterization • Morphological traits• Growth period

Page 19: Yam Physiology

No.

of a

cces

sions

Days from sprouting day to foliage senescence start day

Evaluation of tuber earliness characteristic

Days from sprouting day to foliage senescence start day in DRS

Page 20: Yam Physiology

No.

of a

cces

sions

Days from sprouting day to foliage senescence start day

Evaluation of tuber earliness characteristic

Days from sprouting day to foliage senescence start day in DRS

New acc. will be selected for parental material to develop new variety !!!!!

Early mature varietyLate mature variety

Page 21: Yam Physiology

Summary

Plant Physiology is very important for understanding the plant growth

Whole genome sequence of D. rotundata had already done by IBRC under collaboration research program between JIRCAS, IITA and IBRC.

High quality phenotyping will be key factor for further improvement of yam cultivation

To conduct high quality phenotyping, plant physiology knowledge is very important

Page 22: Yam Physiology
Page 23: Yam Physiology

FemaleMale Monoecious

Evaluation of sex / Flowering characteristic