强耐冷性籼粳亚种间杂种后代孕穗期的耐冷性研究

Cold Tolerance at the Booting Stage of the Hybrids of Indica and Japonica with Strong Cold Tolerance

以云南稻种资源昆明小白谷与大理早籼配制的杂种F2 、F3、F4 、F5和F6等为材料 ,分别在高原粳稻区、籼粳交错区和冬季籼稻区进行强耐冷性籼粳亚种间杂种后代孕穗期的耐冷性研究。结果表明 :(1)昆明小白谷×大理早籼F3、F4 分离群体在不同稻作区每穗实粒数、总粒数与结实率均呈极显著的正相关 ,尤其是昆明点高达 0 .5 86 ～ 0 .776 。 (2 )遗传研究表明 ,可能有 1～ 2对基因影响着籼粳杂种结实率 ,其中有 1对主效基因控制着耐冷基因的表达。利用该群体已选育出了稳定的耐冷性籼粳重组近交系。 (3)不同稻作区不同世代育性分布规律的总趋势是一致的 ,即随着世代的增加耐冷主效基因有累加趋势 ;不同之处在于不同世代的耐冷主效基因和微效基因表达上有差异。 (4 )同世代昆明小白谷×大理早籼杂种后代结实率分布规律为籼粳交错区与冬季籼稻区相似但与与高原粳稻区差异较大。

Cold tolerance at the booting stage of hybrids of indica and japonica rice was analyzed under highland japonica region,cross area of indica and japonica,and indica region in winter by using Kunmingxiaobaigu and Dalizaoxian,Yunnan rice landrace,and their F 2,F 3,F 4,F 5 and F 6 generation. The results showed that (1) Filled grains per panicle,total grains per panicle and seed setting rate of F 3 and F 4 populations were significantly positive correlated in various rice regions, especially in Kunming(0.586 ** ～0.776 ** ). (2)Genetic analysis showed that there were one or two loci of gene affecting the seed setting percentage of hybrids of indica and japonica probably, and one major gene controlling the cold tolerance. A RIL population for cold tolerance in rice was bred from this population. (3)The general trend of fertility distribution of differerent generations at different rice regions is consistent, i.e. the higher generation,the stronger of major gene of cold tolerance,but there are some differences on major gene of cold tolerance and minor gene in various generations. (4)The seed setting rate of the hybrids is similar between cross area of indica and japonica,and indica region in Winter,but different from highland japonica region.\;