大白菜蜡质缺失突变体YW71的遗传及序列变异分析

Inheritance and sequence variation analysis of a wax-less mutant YW71 in Chinese cabbage(Brassica rapa L.ssp.pekinensis)

以大白菜蜡质突变体YW71为对象,研究其亮绿无蜡粉性状的遗传规律和调控基因。通过遗传分析,表明YW71中的亮绿无蜡粉性状由隐性单基因控制。通过等位基因互补实验证明YW71的亮绿性状是BrWAX2等位突变引起的。序列分析表明,在YW71中BrWAX2基因在第3个外显子末端发生了39 bp的缺失,进而引起转录水平的可变剪切和翻译水平的提前终止。表达模式分析表明,BrWAX2基因在YW71茎和叶中表达量显著下降。此外,研究针对39 bp的变异开发并验证了共显性标记BrWAX2-In Del1。研究结果丰富了白菜类蔬菜蜡质突变遗传资源,将为亮绿无蜡粉品种的分子育种提供理论指导和技术支持。

In this study,we identified a wax-less Chinese cabbage(Brassica rapa)mutant YW71,the inheritance and the controlling gene for the glossy trait were studied extensively.Genetic analysis indicated that the glossy trait in YW71 was controlled by a single recessive locus.Allelic complementary experiment showed that the glossy trait in YW71 was caused by mutation of the gene BrWAX2.Sequence analysis revealed that a 39 bp deletion was identified at the end of the third exon of BrWAX2,resulting in alternative splicing at the transcription level and finally leading to a premature stop codon at the translation level.Expression analysis showed that BrWAX2 was significantly down-regulated in stems and leaves of glossy YW71.Furthermore,a co-dominant marker BrWAX2-InDel was developed and validated.Overall,these results enrich the genetic resources of glossy mutants and provide applicable markers for marker-assisted selection(MAS)-based breeding of Chinese cabbage,which has pivotal significance in theory and practice.