在冬小麦籽粒形成期(开花后约14天内),土壤干旱和施用外源 ABA 均可降低穗中部高位小花的结实率。受旱植株营养器官贮存物向穗调运能力增强。植株光合积累物为下降,可以保证穗部在初期的有机营养供应,但中后期供应不足。ABA 有阻抑光合产物向籽粒运输的作用。受旱植株 ABA 含量增大,可能是籽粒形成期干旱降低结实率的重要原因之一。 During the grain-forming period of winter wheat (within about 14 days after flowering), soil drought and application of exogenous ABA reduced the seed setting rate of the upper middle florets. Drought plant vegetative organs storage capacity to transfer to the ear enhanced. Plant photosynthetic accumulation is decreased, can ensure that the spike in the early organic nutrient supply, but the lack of supply in the late. ABA has the effect of inhibiting photosynthetic products transport to grain. The increase of ABA content in drought-stressed plants may be one of the important reasons for the decrease of seed setting rate in drought-induced grain-forming period.