开花期低温胁迫对四川攀西稻区水稻开花结实的影响

以3种籼稻品种和3种粳稻品种为试验材料, 利用人工气候室在开花期进行低温胁迫处理, 研究了低温胁迫对攀西稻区籼、粳稻开花和结实及两者间关系的影响。结果表明, 开花期低温胁迫下籼稻和粳稻的开花习性、花药和花粉特性和结实表现不同。常规粳稻开花对低温有较高的耐冷性。低温胁迫下籼稻品种(组合)花药体积、花药开裂率、可育花粉率、柱头着花粉数和柱头花粉萌发率较对照降低幅度均比粳稻品种(组合)大; 籼稻品种(组合)各产量构成因素较对照降低幅度比粳稻品种(组合)大。相关分析表明, 结实与水稻花药和花粉主要性状有密切关系。开花期低温胁迫影响花药和花粉发育成熟, 使花药不能正常开裂、散粉不足, 可育花粉率和柱头花粉萌发率降低, 直接影响受精结实, 成为结实率降低的主要原因之一。

Effects of Low Temperature Stress during Flowering Stage on Flowering and Seed Setting of Rice in Panxi Region,Sichuan Province

An experiment was conducted in growth chamber with low temperature treatments during flowering stage using three indica and three japonica rice varieties(combinations)to study the effects of low temperature stress on flowering and setting.The results showed that there were different responses and characteristics of flowering,anther,pollen,setting,and their relationship between indica and japonica to low temperature stress during flowering stage.The conventional japonica rice had high cold tolerance to low temperature.In comparison with control,the reduction range of the anther volume,anther dehiscence rate,pollen fertility rate,pollen number on stigma and germination rate of pollen on stigma of indica rice varieties(combinations)under low temperature stress was larger than that of japonica rice varieties(combinations).Under low temperature stress during flowering stage,the reduction range of yield components of indica rice varieties(combinations)was greater than that of japonica rice varieties(combinations).The correlation analysis showed a close relation between the seed setting of rice and the main characters of anther and pollen.It is clear that low temperature stress affects the development and maturation of anther and pollen,further blocks anther dehiscence,resulting in insufficient pollen dissemination on stigma.Meanwhile,low temperature stress also reduces pollen viability and germination ability,and directly affects fertilization and seed setting,which is one of the major reasons for reducing seed setting rate.