多效唑对水稻生长发育及其作用机制的研究

STUDIES OF MECHANISM OF ACTION OF MET ON RICE GROWTH AND DEVELOPMENT

多效唑(MET)处理水稻植株后,使株高降低,分蘖增多,穗粒数下降,与此相应,植株体内的赤霉素(GA_3),生长素(IAA)、玉米素(Z)显著下降,脱落酸(ABA)显著增加。用生长调节剂 GA_3和氮肥可逆转多效唑的抑制作用而便株高增加,给受抑制植株施用GA_3和 IAA,可使植株内 GA_3和 IAA 含量相应上升。因此 MET 可通过调节植株体内 GA_3、IAA、Z、ABA

Field and pot experiments were carried on to study the effects of MET on rice growth and development and its mechanism of action. The results showed that MET was to inhibited shoot elongation,to increase ti- llers,and to decreas the number of grains per spike. The machanism of action of MET was not only to suppress the biosynthesis of gibberllin(GA_3),indole acetic acid(IAA)and zeatin(Z),but also to increas the content of ABA in rice.Application of exogenous GA_3 and nitrogen fertilizer could reverse the retardation effects of MET,increase plant height of rice.In the meanwhile,application of exogenous GA_3 and IAA on rice plant which was inhibited by MET could increase the contents of endogenous GA_3 and IAA. Therefore,it is suggested that the actions of MET on growth and development of rice are through regulating the levels of endogenous GA_3,IAA,Z and ABA in rice plant.