土壤干旱和外源脱落酸对冬小麦结实率的影响

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。

EFFECTS OF SOIL DROUGHT AND EXTERNAL ABA ON SEED-SETTING RATE OF WINTER WHEAT

The seed-setting rate of top floret in the mid-section of spikes in the grain deve- loping stage of winter wheat(during the 14 days after the florescence)can be reduced by soil drought and the application of external ABA.The ability to transport the storables in the vegetative organs of water stressed wheat plants to spikes has been strengthened.Although the accumulation of photosynthetes is reduced,they can ensure the supply of organic nutrients to wheat spikes in the early stage,yet the supply of them is not enough in the middle and late periods.Abscisic acid has the effects upon blocking or inhibiting the transportation of photosynthates to wheat grains.The increase of amount of ABA of water stressed wheat plants is likely to be one of important causes for the low seed- setting rate in grain developing stage.