油菜种子次生休眠遗传多样性的研究
Study of Genetic Diversity of Secondary Dormancy in Three Types of Oilseed Rape

种子因生理代谢改变继而诱导产生次生休眠。研究选育次生休眠性特强和特弱的品种，对防治产区中大量长期存在的地下油菜种子库、田间混杂以及油菜自生苗的泛滥，均具有重要意义。采取实验室聚乙二醇6000诱导次生休眠和4种不同大田埋藏处理相结合的方法，比较甘、白、芥3类油菜共计54个品种(系)在次生休眠特性方面的遗传多样性。结果显示：在大田埋藏处理中休眠特性差异表现显著，次生休眠特性的变异为 0~96.75%，广义遗传率为87.56%~92.56%。所用54个品种(系)中休眠率大于45%的占14.81%，休眠率处于20%~45%的占14.81%，休眠率处于5%~20%的占29.63%，休眠率处于1%~5%的占31.48%，休眠率小于1%的占14.81%。经聚乙二醇6000诱导的种子次生休眠特性的广义遗传率为92.73%。相关性分析表明：田间4种处理方法两两之间均呈极显著相关，与其休眠率结果表现一致；在聚乙二醇诱导法与埋藏处理中，除6个月25 cm处理外的其余3种处理均表现出极显著相关特性。综合比较不同品种（系）类型的休眠率为芥菜型>白菜型>甘蓝型，休眠性受遗传因素的影响程度为白菜型>芥菜型>甘蓝型。
Secondary dormancy is induced by certain metabolism changes.To breed new rapeseed variety with high and low secondary dormancy trait is meaningful to control the long-standing underground seed pool, varietal complexity, and widespread of volunteer seedlings in the field.In this study, genetic diversity of secondary dormancy was evaluated in 54 oilseed varieties using four burial depths in soil or PEG 6000 treatment.In burial treatment, significant differences in secondary dormancy were observed among different varieties of rapeseed.Secondary dormancy varied from 0 to 96.75% based on values was obtained using four burial methods, with broad sense heritability ranging from 87.56% to 92.56%.Varieties exhibiting more than 45% secondary dormancy accounted for 14.81% of the 54 varieties, with 14.81% of the varieties having secondary dormancy rates of 20%-45% and 29.63%,31.48% with secondary dormancy rates of 5%-20% and 1%-5%, and 14.81% with secondary dormancy rates of less than 1%.Broad sense heritability obtained under PEG treatment was 92.73%.Using correlation analysis, we found a significant positive correlation between different periods and depths in the burial treatments.For the PEG-induced seed secondary dormancy data, significant correlations were also found within three of the burial treatments except for 6 month-25 cm depth.The results showed that the secondary dormancy is stronger in the type of Brassica juncea then followed by Brassia campestris and Brassica napus successively.But the comparative analysis of broad sense heritability data showed that the genetic effect of seed secondary dormancy is sequenced in Brassia campestris, Brassica juncea, and Brassica napus in a descending order.