高温对光敏水稻与普通水稻结实率降低方式的分析

报道了对农垦５８Ｓ、农垦５８等６个光敏水稻及常规稻进行光周期反应特性分析中，武昌夏季的自然温度对水稻穗发育及结实率的影响。观察到在较高温度下，５ｄ的ＳＤ处理即可使晚粳穗分化启动并抽穗，表明高温对短日诱导穗分化有明显促进作用；同时还观察到在穗分化启动后，温度对幼穗发育进程的光周期效应也有影响，表现为高温可加强长日对幼穗发育的延迟和短日对幼穗发育的促进，而低温则减弱这种作用。在短日照下，对其在不同温度条件下的结实率与温度的相关性分析发现：光敏不育系的结实率均与幼穗发育期的平均温度呈显著负相关，而常规品种的结实率则主要与抽穗扬花期的平均温度呈显著负相关。因此温度在水稻光敏不育中具特殊效应，这种效应与光周期反应基本无关。

Effects of High Temperature on Decreasing Seed Setting Rate of Photoperiod-Sensitive Genic Male Sterile (PGMS) Rice and Ordinary Rice

The effects of temperature on panicle development and seed setting rate of both photoperiod-sensitive genic male sterile (PGMS) rice and ordinary rice were studied under the natural summer conditions of Wuchang, Hubei using three PGMS lines Nongken 58S, 8902S and C407S and their normal varieties Nongken 58, Nongken 58S (r) and Zhubo 2 as the materials. The results showed that five days of short daylength (10 h) treatment under a relatively high temperature could activate panicle initiation of late japonica rice, and after the starting of panicle initiation, higher temperature could strengthen the delaying effect of long daylength or the enhancing effect of short daylength on panicle development. Under short daylength conditions, it was found that the seed setting rate of the PGMS lines was negatively correlated to the temperature of young panicle developmental stage while that of the normal varieties was negatively correlated to the temperature of heading and flowering stage. It is concluded that temperature has a special effect on seed setting rate of PGMS rice and the effect is independent of photoperiodical reaction.