前言在小麦生产中,穗粒数是产量的构成因素之一,研究提高穗粒数的途径对增产有着重要的意义。穗粒数的增减与小花的分化和退化的关系密切。每穗所形成的小花总数大大超过开花数,然而,大部分小花于开花前退化;开花后又有部分小花不实而继续退化,可见增加穗 Introduction In wheat production, the number of grains per spike is one of the components of the yield. It is of great significance to study ways to increase the number of grains per spike. There is a close relationship between the increase and decrease of grains per spike and the differentiation and degeneration of floret. The total number of florets formed per panicle greatly exceeded the number of flowering, however, most of the florets degenerated before flowering; some florets did not grow but continued to degenerate after flowering,