前言 最近十年来,国内外所报导的资料证明:水稻和其它谷类作物—样,在个体发育的后期(特别是第三发育阶段)是一个转捩时期。此时正是从花粉母细胞出现到四分体形成时期,对低温、强光,暴风和阵雨所引起的大气振荡,及营养物质的供应不良等不适宜的因素,直接或间接地导致花粉母细胞 Foreword In the recent decade, the data reported at home and abroad have proved that rice and other cereal crops are in the later stages of development (especially the third stage of development) as a turning point. At this time, it is from the period when pollen mother cells appear to tetrad formation. The unfavorable factors such as low temperature, strong light, atmospheric oscillation caused by storm and shower, and poor supply of nutrients directly or indirectly lead to pollen mother cell