Physiolgoical Studies on the Vernalization of Wheat Plants. : IV The effects of temperature and photoperiod on the progress of vernalization in growing plant.

[摘要] The experiments were conducted in order to find out the effects of daily alternating temperature and photoperiod on the progress of vernalization, that is defind as the process leading to ripeness-to-flower, in the growing plant of wheat, Norin No. 64, medium cold requiring variety. The relation beween the progress of vernalization in plant as manifested by the vernalization test, and the turn-over of morphogenetic ability in shot apex, revealed by the excised stem tip culture, were also determined. From the results of these eyperiments, following inferences may be drawn; 1), The rate of vernalization depends on temperature and not on photoperiod. The vernalization in growing plant may complete within one month even under as high a mean temperature as 19°C. These facts may be explained by the information contained in the following paragraphs, 2) and 3). 2). The daily lower temperature at night apparently controls the rate of vernalization, while higher temperature during daytime has little effect on the rate. The fact that the daily day temperature above 30°C permits the rapid vernalization, when the daily night temperature is below 10°C, suggests the devernalization in the plants grown under field conditon to be improbable. 3). Althogh low temperature promotes the onset of vernalization, it is not a requisite for its completion. The turn-over of morphogenetic ability in shoot apex occurs in the earlier cold-requiring phase of vernalization.

[学科分类] 农业科学（综合）