水稻亚种间杂种不育性的遗传分析

Genetic Analysis for the Hybrid Sterility of Intersubspecific Crosses in Rice

利用4个亚种间亲和性品种(ICV)配制单交(F_1和F_2)及三交组合,研究了水稻籼粳杂种不育性(亚种间亲和性)的遗传。结果表明:籼稻IR58和二九丰之间、粳稻秀水117和T8340之间存在不育座位的分散(或不等位)分布。不同类型三交组合结实率的变异表明,亚种间亲和性基因具有重组和累加效应。无论F_1结实率高低,其F_2群体均存在较大的育性分离,含有3个ICV的三交组合F_1亦如此,这种分离可能是由于亲本中不育座位分散分布及基因重组的结果。3对糯-非糯近等基因系与ICV的三交组合分析表明,亚种间亲和性基因与糯质基因间不存在明显的连锁关系。认为籼粳亚种间F_1的不育性(亚种间亲和性)由多基因控制,基因的加性和上位性效应可分别用于解释两种类型的亲和性——一般(广谱)亲和性和特殊(狭谱)亲和性。

To examine the genetic mechanism of indica-japonica hybrid F_1 sterility of rice, single crosses (F_1 and F_2) and three-varietal crosses (TVC) were made, using 4 intersubspeciflc compati- ble varieties (ICV) as parents. The results indicated that there were some dispersed (nonallelic) sterility loci between indica IR 58 and Erjiufeng and between japonica Xiushui 117 and T8340. The variation of fertil- ity within each TVC of different types revealed the recombination and accumulation effects of IC genes. The great segregation of sterility was found in both F_2 populations, from either high or low fertile F_1 s, and the TVCs from three ICVs, which could be attributed to the dispersive distribution and recombination of sterility loci of parents. By use of three pairs of waxy and isogenic nonwaxy lines to make TVCs with ICVs, a further research indicated that there was no evidence of linkage relationship between wide compatible genes and waxy gene. A polygenic system with more than one locus was considered to be responsible for the F_1 sterility (compatibility). Two kinds of gene actions, additive and epistasis, could be respectively used to explain the two kinds of compatibilities, general (wide) and special (narrow) compatibilities.