小麦幼穗分化的温光反应研究──春化对小麦幼穗分化的效应

在生长箱控制条件下，利用６个春麦品和３个冬小麦品种进行春化实验，着重研究了春化处理对小麦穗分化各个阶段的效应．结果表明，①伸长期：春化处理使伸长期所需积温值降低，叶龄值减少，但延长出苗－伸长期持续天数；②伸长－二棱初期：该期的实际天数、所需积温值及二棱期的叶龄值均随春化处理而降低，其实际天数与出苗至抽穗期的相关系数达到０．９７０８；③二棱初期－护颖期：该期实际天数、所需积温值及护颖期叶龄值也随春化处理而降低，其实际天数与出苗至抽穗期天数的相关系数达到０．７９８６．因此，春化效应不仅表现在促进小穗原基分化的开始，而且加快小穗分化的完成．春化处理对护颖期以后的穗分化过程影响很小．本文认为．应将护颖分化期视作春化效应结束期而非春化阶段结束的标志。

STUDIES ON THE RESPONSE OF WHEAT SPIKE DIFFERENTIATION TO TEMPERATURE AND DAYLENGTH──Ⅰ.Effect of vernalization on differentiation of wheat spike

In Conviron phytotrons, six spring wheats and three winter wheats were used to investigate the effect of vernalization on differentiation of wheat spike. The result showed that:(1)The thermal time needed for appearance of apex elongation was reduced by vernalization. so was the leaf-age at this stage. However, the calender days from emergence to apex elongation increased.(2) Both the calender days and the thermal time from apex elongation to appearance of double ridge(DR) were reduced, so was the leaf -age at DR. The correlation coefficient between the duration of this stage and days to heading is 0.9708￣** .(3) From DR to glume differentiation, the same tendency was obtained as in the last stage, and the correlation coeffeient between the duration and days to heading is 0.7986￣**.Therefore, vernalization had enhancing effect not only on the appearance of spikelet primordia, but also the fulfillment of their differentiation process.On the other hand, vernalization hardly affected the differentiation stage after glume differentiation . It is suggested theat the stage of glume differentiation be taken as the expiration of vernalization effect rather than the remark of the fulfillment of vernalization phase.