淹水胁迫条件下甘蓝型油菜发芽期耐湿性的配合力分析

【目的】研究甘蓝型油菜发芽期耐湿抗性的遗传机制,为合理选配亲本和选育耐湿品种提供理论依据。【方法】选择6个耐湿性不同的甘蓝型油菜品种配制完全双列杂交组合,在水淹胁迫条件下萌发亲本及F1代种子,测定萌芽种子的相对根长、相对茎长、相对单株鲜重、相对芽苗率、相对电导率和相对活力指数,用GriffingⅠ方法对发芽性状的一般配合力和特殊配合力进行遗传分析。【结果】在30个组合间,各性状的一般配合力方差达到极显著水平,特殊配合力方差除了单位电导率外也达到极显著水平。遗传效应分析表明:相对于其它5个性状,作为最能代表甘蓝型油菜耐湿性的相对活力指数,其狭义遗传率最大,而广义遗传率相对较小。品种中双9号和P79相对活力指数的一般配合力效应最高,具有较大的利用潜力。【结论】分析发芽期相对活力指数的配合力和遗传效应,可以有效地鉴定甘蓝型油菜种子萌发期的耐湿性,为耐湿育种进行早期世代选择提供理论依据。

Combining Ability and Genetic Effects of Germination Traits of Brassica napus L. Under Waterlogging Stress

[Objective] Cross combinations from six rapeseed cultivars and lines were investigated under waterlogging stress in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L. and to provide reasonable improvement programs. [Method] Six germination traits were investigated under waterlogging stress on the combining ability and heritability using complete diallel crossing method designed for 30 combinations from six cultivars and lines. The traits include relative root length, relative stem length, relative fresh weight per plant, relative survival rate, electrical conductivity and relative vigor index. After flooding treatment, the six traits of parents and F_1 were measured and the general combining ability (GCA) and special combining ability (SCA) of germination traits were analyzed using Griffing Ⅰ method. [Result] Among 30 cross combinations, the GCA was significantly different among the 6 waterlogging resistance traits. The SCA of these traits was significantly different except the SCA of electrical conductivity. As the representative trait of rapeseed tolerance to waterlogging, relative vigor index had the highest narrow beritability and relatively low broad heritability. Cultivar Zhongshuang 9 and P79 had high tolerance potential to waterlogging. [Conclusion] The combining ability and genetic effects analysis of relative vigor index during germination stage can be used to identify the waterlogging tolerance of rapeseed and improve the breeding program.