甘蓝型油菜遗传多样性及其与杂种表现的关系

Relationships between Genetic Diversity and Hybrid Performance in Oilseed Rape (Brassica napus)

以 3个双低甘蓝型油菜自交不亲和系、 2 2个不同来源的父本品种及其按 NC 法配制的 6 6个杂种为材料 ,应用 AFL P及 RAPD标记技术研究亲本的遗传多样性及遗传距离与杂种产量、含油量的关系。结果表明 ,根据遗传距离可将 3个自交不亲和系分为 2组 ,SI- 130 0和 SI- 1310为一组 ,SI- 132 0单独为一组 ;父本品种分为 5组 ,中国品种为 1组 ,国外品种分属另 4组。各父、母本组间在产量性状及种子含油量上存在明显差别 ;两组自交不亲和系与不同组父本配制的杂种间大多数产量性状的表现不同 ,来源于国外品种的杂种平均优势明显强于国内品种。分子标记遗传距离与杂种单株产量极显著正相关 ,而与种子含油量极显著负相关 ,但两者的决定系数均较小 ,分子标记遗传距离难以预测甘蓝型油菜自交不亲和系杂种的产量。

double low self incompatible lines and 22 male parent varieties of Brassica napus from different origins, together with their 66 hybrids produced in a North Carolina mating design Ⅱ(NCⅡ), were used to detect genetic diversity among parents and estimate genetic distance (GD) and analyze the relationship between hybrid performance and GD with the utilization of amplified fragment length polymorphism (AFLP) and random amplified polymophic DNA (RAPD). The results indicated that 3 self incompatible lines and 22 male parents might be divided into two and five groups, respectively, based on GD S Among 22 male parent varieties, those from China were clustered into one group, and those from foreign countries were clustered into other four groups. Significant differences in yield traits and seed oil content were observed among the two female and the five male parent groups. Hybrids produced by foreign male parents exhibited higher mid parent heterosis for seed yield per plant than those produced by Chinese male parents. Hybrid yield per plant and seed oil content showed significant positive and negative correlations with genetic distance, respecively, but the determination coefficients ( R 2) were low. It appeared to be unsuitable for using AFLP and RAPD based genetic distance to predict hybrid performances of self incompatibility in Brassica napus.