恢复系和保持系RAPD分子标记与甘蓝型油菜杂种优势关系的研究

Studies on relations of RAPD markers and heterosisin Brassica napus L.

以6个甘蓝型油菜不育系及其同型保持系、5个恢复系及不育系同恢复系按NC (6×5)设计配成的30个杂交组合为材料,利用RAPD分子标记研究油菜遗传距离与杂种产量、杂种产量优势、特殊配合力的关系。结果表明:23个RAPD引物在6个保持系和5个恢复系间共扩增出89条多态性条带,据此计算出亲本间的相似系数为0.2706～0.6164。聚类分析将参试的6个保持系和5个恢复系分为4组,第1组包括6个保持系和1个恢复系C5,第2组包括C1和C42个恢复系,第3组包括1个恢复系C2,第4组包括1个恢复系C3,亲本分组结果与其地理来源关系不大;方差分析表明,组合间产量差异达极显著水平。特殊配合力与产量、产量杂种优势的相关关系达显著水平,但亲本遗传距离与杂种产量、产量杂种优势、特殊配合力的相关关系都未达显著水平,表明不能根据亲本RAPD遗传距离的大小预测杂种产量及产量杂种优势。

The relationship between genetic distance and F_1 yield /yield heterosis/special combining ability were analysed using RAPDs technique.The materials consisted of 6 cytoplasmic male sterile lines and their maintainers,5 restorers and their 30 crosses by NCⅡ (6×5) mating design.The results of this study showed as following:A total of 89 polymorphic bands were generated by 23 RAPD primers.Based on the polymorphisms generated by the markers,calculated similarity index values ranged from 0.270 6 to (0.616 4).Cluster analysis placed 6 maintainers and 5 restorers into 4 groups.The first group included all 6 maintainers and one restorer C5,the second group included two restorers C1 and C4,the third and fourth group only included C2 and C3 respectively.The grouping of the lines was not in agreement with the available pedigree date on their geographic origin.Analysis of variance among 30 F_1 hybrids revealed significant difference for seed yield.There existed significant relationship between special combining ability and F_1 yield/yield heterosis,but the correlation between genetic distance of parents and F_1 yield/yield heterosis/special combining ability failed to reach significant level,which meant RAPD genetic distance can not be used to predict the heterotic performance of hybrid cross.