孕穗期低温对冬小麦穗部及籽粒的影响

摘要

Under the condition of late spring low temperature in Qingdao in April 2013,the influences on spikes and grains of winter wheat were investigated.The results showed that the tested wheat spikes got frozen in different degrees,each wheat spike had several abnormal spikelets,and of which the anther was also abnor-mal in flowering period.The analysis on setting percentage of abnormal spikelets showed that the average grain number was 2.26,which were 1 ~2 grains less than that in ordinary year,and the emptygrain percentage was 4.0%.Further analysis revealed that compared with normal grains,the grains of abnormal spikelets were wiz-ened.There was no significant difference in grain length between normal and abnormal grains,while the grain width was significantly lower and the thousand grain weight was extremely significantly reduced than those of normal grains.The number of abnormal spikelets per spike (NASS)and the frequency of abnormal spikes (FAS)in 30 sample spikes were analyzed under no irrigation and irrigation once before low temperature.The results showed that under no irrigation condition,the average values of NASS and FAS were 4.86 and 92% re-spectively,while those under irrigation once condition were 3.96 and 78% respectively.It indicated that irri-gating before late spring low temperature at booting stage could reduce the injury degree on spikes of winter wheat.This study also listed the real time monitoring temperature and soil water regime in 5 days during the happening period of low temperature at booting stage,which could provide references for the setting of manual simulation environment in the further study of booting stage low temperature.%2013年4月小麦孕穗期出现低温，对其穗部及籽粒性状进行调查后发现，供试材料穗部不同程度地出现受冻现象，每个穗子有数个畸形小穗，畸形小穗的花药也出现异常。对畸形小穗的结实率进行分析表明，畸形小穗平均结实数为2．26，较常年减少1～2粒，空壳频率为4．0％。进一步分析发现，畸形小穗的籽粒较正常籽粒明显干瘪，粒长与正常籽粒无显著差异，但粒宽显著降低，千粒重极显著低于正常籽粒。对低温来临前浇水和不浇水处理的每穗畸形小穗个数（NASS）和畸形穗率（FAS）进行统计，结果为：不浇水条件下NASS 和 FAS 均值分别为4．86个、92％，浇一水条件下 NASS 和 FAS 分别为3．96个和78％，表明在孕穗期低温来临前浇水比不浇水能够在一定程度上减轻危害程度。本研究列出了孕穗期低温发生期间5天的实时监测温度和土壤水分状况，可对孕穗期低温研究中人工模拟环境的设定提供一定参考。