[Changes of wheat seed vigor at different development stages and their response to environmental temperature].

Two wheat cultivars (Jimai 22 and Shannong 23) were selected to investigate the changes of seed vigor at different development stages in different years by standard germination test, and the effect of environmental temperature on it was also analyzed, which would provide a theoretical basis for the utilization of early wheat seeds and the production of high vigor seeds. The results showed that the germination ability of fresh seeds appeared around 26 d after anthesis, and then the germination rate of fresh seeds displayed an overall upward trend with the development of wheat seeds. The germination energy, germination rate and germination index of dry seeds rapidly increased from 5 d to 8 d after anthesis, and then remained relatively stable, while the vigor index increased continually and reached the peak 4-6 days before the end of ripening due to the increase of seedling dry mass.