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タイトルTit le

Effects of Temperature and Storage Humidity upon the Respirat ion ofPollen in Corn Plant(玉蜀黍花粉の呼吸に及ぼす温度と貯蔵湿度の影響)

著者Author(s) Nishikawa, Kin-ichi

掲載誌・巻号・ページCitat ion 兵庫農科大學研究報告. 農学編,3(1):11-13

刊行日Issue date 1957

資源タイプResource Type Departmental Bullet in Paper / 紀要論文

版区分Resource Version publisher

権利Rights

DOI

JaLCDOI 10.24546/81006539

URL http://www.lib.kobe-u.ac.jp/handle_kernel/81006539

PDF issue: 2021-07-31

EFFECTS OF TEMPERATURE AND STORAGE HUMIDITY UPON

THE RESPIRATION OF POLLEN IN CORN PLANT

Kin-ichi NISHIKAWA

INTRODUCTION

Many studies have been carried out on the phisiological basis of pollen germination, and it has been cleared that the germination percentage and the pollen tube growth are affected by the envitonmental conditions. In contrast with the detailed studies on the pollen germination, very few reports (OKUNUKI3){) (1932, 33) in lily (Lilium auratum, LINDL) and tea (Thea sinensis, L.» are found on the respiration of pollen. The author has made experiments on pollen resipraion of corn plant dividing into the follow ing three parts.

(I) Relation of sucrose concentration in medium to the respiration of pollen grains.

(II) Effects of humidity during storage on the viability of pollen grains.

(III) Effects of temperature on the respiration of pollen grains.

These investigations were carried out under the kind guidance of Dr. N. ENOMOTO in 1954.

MATERIAL AND METHODS

Pollen were collected from the plants of Choko-202, a newly bred variety. In collecting pollen, YAMASAKI'S method7) (1943) was used. The rate of respirotion was measured by WARBURG respirometer and the procedures of the measuring were as follows:

Experiment I-Exactly weighted 50mg. pollens were poured into the respirometer vessels, and 1 cc sucrose media of each five concentrations (0, 10, 20. 30, 40%) was added respectively to them. The vessels set to the apparatus were vibrated in the water bath kept at 35°C constant.

Experiment II- The pollen were stored in parchment paper bags under four different rela­tive humidities (0, 30, 50, 80%) at room tempera­ture for 24 and 48 hours. The humidities of desicators in which pollens were stored. were re­gulated using different concentrations of sulphuric acid. Both the stored pollens in the desicators and the fresh ones sampled from field were measued, the latter being taken as a control. The rate of respiration was measured in the same manner as in the experiment r. but sucrose concentration in medium was 30%. which was proved to be the best in expeiment I.

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Experiment III-The rate of respiraton of pollen were examined at several constant tempera­tures (25, 30, 35, 40, 45, 50, 60 and 70°C). The sucrose concentration of medium was also 30% and other procedures were the same as in the above two experiments.

In the experiments I and II. the measurements were repeated 3 times, but in the experment III. 2 times at each temperatures. Replications in each experiments gave results hardly deviated from each other.

RESULTS AND DISCUSSION

I. Relation of sucrose concentration in medium to the respiration of pollen grains.

OKUNUKI{) (1933) found that the pollen germina­tion and pollen tube growth were promoted at a certain concentration of sucrose. According to his opinion. this promotion may be attributable to the adequate osmotic concentration of the medium rather than to the nutritive effect of sucrose. SHISA~) (1954). USing petunia pollen. also reported that the protuberance from the pollen grain is merely due to the osmotic pressure.

The results obtained in this experiment are given in Fig. 1.

___ lI ___

--1

~ 0 •

1<0. 2 0.

1 o. 0 ,

20 ,0 40 50 ~_ (.w... ....

Fig. 1. Graph showing the change of respira­tion rate of corn pollen in process of time under different concentrations of sucrose in media.

ScI. Rep. Hyogo Univ. Agric. \'01. 3. No. 1

According to Fig. 1. the increase of the respira­tion rate as time passages by was small under low concentrations (0. 10%) of sucrose in media. while those are large and Iiniar under high concentrations (20. 40%). And the respiration rate as the con­centrations increased up to 30%. decreasing a gain at 400/0.

These results may show that a 30% sucrose medium will give a favourable osmotic condition to the respiration of corn pollen.

II. Effects of humidity during storage on the viability of pollen grains.

In general. the viability of pollen remains longest under conditions of low temperature and low humidity. The corn pollen . however. loses their viability rapidly on exposure to low humidity.

According to ANDRONESCU1) (1915). corn pollen stored in a desicator. the viability remained only twenty minutes. SASAKI~) (1925) stated that favourable storage condition of corn pollen was given under a relative humidity of 50%. under which the viability remained for about three days. In those investigations. pollen viability was ex­pressed by the pollen germination power.

The results obtained are shown in Fig. 2. according to which the respiration rate per hour. when stored for 24 hours were as follows:

Storage humidity Respiration rate Compared to (%) (02 pl/mg) control(index)

Control 3.37 100 80 2.12 62.9 50 1. 33 39. 4 30 0. 53 15. 7

0 0.52 15.4

100

II ! 0 :. 407 .t ..... ,. -i -2 dql etoNp , G

~O

o ocntl'ol 8 0 5 0 ,0

500 .... hwa1d1tr ( " )

Fig. 2. Graph showing the effects of humidity during storage on the respiration of pollen grains. 02,uptake was measur­ed at 35°C and in 30% sucrose medium. and expressed as indices of respiration rate. representing as 100 for Q<>z of control.

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Thus. the corn pollen which were stored under high humidity conditions held higher respiration rate than those under low humidity. In addition when stored for 48 hours. the respiration rate became very low under a ll humidity conditions.

From these facts. it is evident that the viability of corn pollen reduced rapidly on exposure to low humidity. that is. the life of corn pollen are shortened strikingly.

II I. Effects of temperature on the respiration of pollen grains.

Temperature is one of the most important environmental factors affecting the respiration. In higher plants. the respiration is generally very low at temperatures close to O°C. it increases gradually with rising temperature. and shows a maximum rate when temperature reaches 40° to 50°C.

According to a review of literature by BARILEY and GURJAR1) (1918). PFEFFER (1 878) observed that the intensity of respiration increases with the rising temperature until the plant begins to retard all the vital processes. HOFF (1896) stated that the respirat ion rate increases two or three times for each 10°C rise in temperature. but it is true within a certain limit. ZIEGENBEIN (1893) found that temperatures above 45°C were disturbing for the respiration. CLAUSEN (1890) studied the respiration of germinating wheat seeds at different temperatures and found the optimum to be about 40°C. The average increase was as 2.71 times as in initial for each 10°C increase between 0° and 40°C. BAILEY and GURJAR1) (1918). having used

4 45' C

r --v-- 40'c

:. - x- , 5' C

-a: ,0·0

~ O-C

j --- 2 ~·o , 5 5'0

~ ---2

•

,.-- .....--.P

1

"Ullie la1n\lt. .. )

Fig. 3. Graph showing the effects of tempera­tUJ:e on the respiration of pollen grains. 0 2-uptake was measured in 30% sucrose medium. and expressed pi per mg.

XII, 1957 Series: Agriculture

Table 1. Rffects of temperature on the respiration of pollen grains.

Tempera- Rete of respiration (O~ til per mg)

tures (0C) -Time (Minutes) Index of

10 20 30

25 0.30 0.63 0.88 30 , 0.52 1. 00 1. 49 35 0.66 1. 27 1. 86 40 0. 62 1. 40 2.03 45 0.81 1. 42 2.12 50 0.91 J. 39 1. 75 55 0.44 0.60 0.67 60 0.24 0. 33 0. 45

Fig. 4. Graph showing the effects of tempera­ture on the 'respiration of pollen grains . Oz-uptake was measured in 30% sucrose medium, and expressed as indices of respiration rate per one hour. reo presenting as 100 for 45°C.

wheat plants. also showed that the respiration rate reached its maximum at 55°C.

The results of this experiment were as shown in Table 1 and in Fig. 3 and 4.

The graph in Fig. 3 and 4 shows that the respiration rate increases gradually and uniformly with rising temperature between 25° and 45°C ; while at 50°C and over. the rate falls rapidly and shows the zero at 70°C.

As seen above. the relation of temperature to the respiration of corn pollen was parallely circumstanced with those observed in the tissue or plant itself by others.

SUMMARY In contrast with many detailed studies having

hitherto been made on various aspects of the pollen germination. rather very few reports OKUNUKI1)4) (1932. 33) in lily (Lilium auraturn. LINDL) and tea (Thea sinensis . L.» are found on problems of respiration of pollen. The author

, has made experiments on pollen respiratiration I of c;orn plants.

Pollens were collected from plants of a newly bred variety Choko·202. In collecti~g pollens. the method of YAMASAKI7) (1943) was used. and the

. respiration rate of pollens were measured by

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40 50 60 Q0 2 - -----1.10 1. 40 1. 57 39.0 1. 94 2. 42 2.82 70.1 2.40 2. 93 3. 37 83. 8 2.72 3.37 3.99 99.2 2. 96 3. 44 4.02 100 1. 78 1. 81 1. 81 45.0 0. 72 0.72 0.72 17.9 0.50 0.52 0.52 12.9

WARRURG respirometer. The main results were as follows:

(1) The respiration rate was small under low concentration (0. 10%) of sucrose. and it rose as the concentration increased up to 300/0 decreasing again at 400/0.

(2) As to the effects of humidity during storage on the viabil ity of pollen grains. when stored for 24 hours, pollens which were stored under high humidity (50,80%) held higher respira­tion rate than those under low humidity (0.30%) and the maximum rate was observed at a relative humidity of 80%. In addition. when stored for 48 hours , the respitation rate became very low under all humidity conditions.

(3) The respiration rate increased gradually as the temperature rose from 25° to 45°C, and it reached maximum at 40° to 45°C. Then. the rate fell rapidly at 50°C and became zero at 70°C.

(Laboratory of _ Food Crop Science, Received Aug. 28, 1957.)

LITERATURE CITED

1) ANDRONESCU. D. I. (1915): The physiology of the pollen of Zea mays with special regard to vitality. Thesis Univ. 3. (Cited from YASUDA, S.)

2) BAILEY, C. H. and GURJ'AR, A. M. (1918): Respiration of stored wheat. Jour. Agr. Res. 12, 685- 713.

3) OKUNUKI. K . (1932): Uber den Gaswechsel der Pollen. (Japanese) Bot. Mag. 47.45-62.

4) --(1933): Uber den Gaswechsel des Pollens von Thea sinensis. L. (Japanese) Bot. Mag. 47, 300-312.

5) SASAKI, T. (1925): On the storage of pollen of cereals. Jour. Scient. Agr. Soc. 275. 259-287.

6) SHISA. M. (1954): Physiological Studies on Pollen I. The influence of carbohydrate substances in media on the germination of petunia pollen. Jap. Jour. Breed. 4, 164-170.

7) YAMASAK I. Y. (1943): A method for collect­ing pollens in corn. Ikushu-Kenkyu 2, 65-66.