甘蓝型油菜轮回选择研究　Ⅱ．基础群体的合成和选择效果的初步评价

RECURRENT SELECTION IN BRASSICA NAPUSL. Ⅱ. SYNTHESIS OF A BASIC POPULATION AND PRELIMINARY EVALUATION OF SELECTION TO THE POPULATION

以显性核不育基因Ｍｓ为异交媒介，用７５个具有期望农艺和品质性状的甘蓝型油菜育种材料，配制了含有１２种细胞质类型的杂交组合，将这些组合在隔离条件下随机交配２次，合成了供轮回选择用的基础群体（Ｃｏ）。随机交配群体各代有约４０％的不育株。群体内稳定的低芥酸基因型频率表明，各代个体间随机交配是充分的。Ｃｏ群体的可育、不育亚群体间单株种子重和品质性状存在差异。首轮对品质性状的选择进展明显。Ｓ１家系评价表明，Ｃｏ群体具有较高的产量潜势。所得结果初步显示，利用Ｍｓ基因进行甘蓝型油菜产量改良是一条有效的育种途径。

A basic(Co) population originated from 72 crosses produced from 75 breeding materials with desired quality and agronomic traits has been synthesized after two times of random mating mediated by a dominant male sterile allele,Ms,in Brassica napus. The population contained 12 different types of cytoplasm. There were about 40% sterile piants segregating each generation in random mating populations,and assessment based on the frequency of low erucic acid genotypes showed that random mating was complete in each generation. The differences of seed weight and quality traits were observed between sterile and fertile sub-populations in Co population. Obvious progress of selection for quality was obtained after one cycle of selection.Test of S1 family lines selected from fertile plants in Co population showed that the synthesized population had wide variation and relative high potential in seed yield. The study provided evidences that recurrent selection facilitated by Ms allele is a practical and promising approach for the improvement of seed yield potential in Brassica napus.