重组型白菜的细胞学及分子遗传解析

Cytological and molecular genetic analysis of restituted Brassica rapa

异源四倍体甘蓝型油菜(Brassica napus,AACC,2n=38)是研究异源多倍体植物起源、进化的一种模式植物。先前的研究中,通过甘蓝型油菜与近缘种植物杂交,诱导C亚基因组染色体优先消除,重建了祖先种白菜类型(restituted B.rapa,RBR,AA)。本研究通过雌蕊细胞染色体压片技术,扩增片段长度多态性(AFLP)技术对已获得的2个重组白菜及其连续自交后代进行细胞遗传及系统聚类分析。结果显示:2个重组白菜及其自交后代的染色体数稳定在2n=20;与天然白菜相比,RBR在表型上表现一些特有的性状;经AFLP分子标记分析RBR Oro与白菜"Chiifu"聚为一类,RBR ZS11与本土的白菜型油菜"白油1号"亲缘关系紧密。结论:重组白菜在染色体组水平上具有稳定性,且重组白菜主要依赖于亲本甘蓝型油菜的起源。

The allotetraploid oilseed rape（Brassica napus L.,AACC） had been taken as a model to decipher the formation and evolution in allopolyploid plants.In previous study,two ancestral B.rapa had been restituted（restituted B.rapa,RBR,AA） in intertribal crosses between B.napus and and its relative species via inducing the preferential elimination of C-subgenome chromosomes.Here,counting chromosome number of pistil cells and Amplified Fragment Length Polymorphism（AFLP）technology were performed to analyze the genetic stability and phylogenetic analysis of RBRs and their descendants.The results demonstrated that：RBRs and their descendants maintained a stable chromosome number with 2n=20;Comparing to nature B.rapa,RBRs showed some special characteristics at morphology;RBR Oro shared a similar cluster with B.rapa ＂Chiifu＂ and RBR ZS11 showed the most closest relationship with native B.rapa ＂baiyou1hao＂which were determined by AFLP.We concluded that RBR can maintain the stability at chromosome level and the phylogenetic analysis of RBRs was proved to depend on the origin of its parental B.napus.