高结实率多倍体水稻杂种F_2代分子标记的分离分析

Segregation Analysis of Molecular Markers in F_2 Generation of Polyploidy Rice Hybrid with High Seed-setting Rate

[目的]为多倍体水稻的育种提供理论基础。[方法]测定高结实水稻杂交组合PSR120 F2代群体的结实率,利用SSR分子标记分析其遗传多样性。按结实率和分子标记基因型对PSR120 F2单株进行动态聚类,研究结实率与标记基因型的关系,并探索标记的杂合度与结实率的相关性。[结果]PSR120的F2代结实率的变异范围较大,而F1代的结实率变异范围不大,这表明与结实率有关的基因在F2代发生了分离。结实率的分布不对称,结实率较高的单株所占比例较大。根据结实率,可将PSR120 F2单株分为高结实率组和低结实组。水稻植株的杂合度越高,平均结实率就高。在低结实率组中,杂合度与结实率呈线性正相关,而在高结实率组中二者呈负相关。[结论]PSR120 F2代具有较强的杂种优势。

[Objective] The aim of the research was to provide the theoretical foundation for the breeding of polyploid rice. [Method] The seed- setting rate of F2 population of rice hybrid combination PSR120 with high seed-setting rate was determined and its genetic diversity was analyzed by SSR molecular marker. The dynamic clustering was made on F2 single plants of PSR120 according to the seed -setting rate and molecular marker genotype. The relationship between the seed -setting rate and the marker genotype was studied and the correlation between the marker heterozygosity and the seed-setting rate was discussed. [Result] The seed-setting rate in F2 generation of PSR120 had larger variation range, while that in Ft generation was not large. This indicated that the related gene with the seed-setting rate was separated in F2 generation. The distribution of the seed -setting rate was not symmetrical and the single plants with higher seed -setting rate took greater proportion. According to the seed - setting raie, F2 single plants of PSR 120 could be divided into the group of high seed-setting rate and the group of low seed-setting rate. The higher the heterozygosity of rice plants was, the higher the average seed-setting rate was. The heterozygosity showed a linear positive correlation with the seed -setting rate in the group of low seed -setting rate, while the two showed a negative correlation in the group of high seed -setting rate. [Conclusion] F2 generation of PSR120 had stronger heterosis.