基于BSA-seq技术对甘蓝型油菜矮秆性状的显著关联区域和候选基因分析

Analysis of significantly associated regions and candidate genes for dwarf stem trait in Brassica napus based on BSA-sequencing

【目的】解析油菜矮秆性状调控遗传位点及关键基因,为油菜株高性状改良和抗倒伏油菜品种选育奠定基础。【方法】利用矮秆油菜DW1分别与高秆油菜WH14和WH20进行正反交,探究F_(1)代和F_(2)代矮秆性状遗传规律。同时,利用BSA-seq技术对油菜DW1和WH20的F2分离群体中极端高秆和极端矮秆2个DNA混池测序并鉴定矮秆性状的显著关联区域和候选基因。【结果】(1)油菜DW1矮秆性状为质量性状,由1对不完全显性基因控制。(2)在A06染色体21.78—23.88 Mb鉴定到22个与矮秆性状显著关联区,其中置信区间最大为46.71 kb,最小为0.64 kb。(3)在A06染色体上与矮秆性状显著关联区域鉴定到BnaA06g27050D、BnaA06g34100D、BnaA06g34810D、BnaA06g35080D和BnaA06g36480D,其功能涉及植物生长素调控和赤霉素信号转导。【结论】油菜DW1的矮秆性状属于质量性状,由1对不完全显性基因控制。A06染色体上的21.78—23.88 Mb区域为矮秆性状显著关联区域,该区域包含5个候选基因,其功能与植物生长素生物合成和赤霉素信号转导相关。

[Objective]The study aims to reveal the genetic loci and candidate genes associated with the dwarf trait in Brassica napus,laying a foundation for the improvement of plant height and the breeding of lodging resistant B.napus varieties.[Methods]Rapeseed dwarf stem DW1 was used to cross with tall stem lines WH14 and WH20,respectively,and the F_(1)and F_(2)generations were used to analyze the genetic mechanism behind the dwarf trait.Meanwhile,two mixed DNA pools,one from extremely tall and the other from dwarf stem lines,constructed from F2 segregated population of dwarf stem DW1 and tall stem WH20 hybrid combination,were sequenced and analyzed base on BSA-seq technology,and the significant association regions and candidate genes associated with dwarf trait were identified.[Results](1)The dwarf trait of B.napus DW1 was a quality trait and was controlled by one pair of incomplete dominant genes.(2)Twenty-two genomic regions significantly associated with dwarf trait were identified within the 21.78-23.88 Mb region on chromosome A06,with the maximum interval of 46.71 kb and the minimum interval of 0.64 kb.(3)Potential candidate genes,including BnaA06g27050D,BnaA06g34100D,BnaA06g34810D,BnaA06g35080D,and BnaA06g36480D,were identified in significantly associated regions on chromosome A06,which were related to the regulation of auxin and gibberellin signal transduction,respectively.[Conclusion]The dwarf trait herein is a quality trait controlled by one pair of incomplete genes.One significantly associated region was identified in the region from 21.78-23.88 Mb on chromosome A06.Five candidate genes within the significantly associated regions were identified and involved in the regulation of plant auxin synthesis and gibberellin signal transduction.