芥菜型油菜每角籽粒数QTL的上位性互作和环境互作分析

QTL epistatic effects and its interaction with environment in Brassica juncea L.

【目的】为揭示芥菜型油菜及芸薹属作物每角籽粒数形成的分子机理,提高和改良芥菜型油菜产量和育种工作奠定基础。【方法】研究以包含221个芥菜型油菜株系的重组自交系(recombinant inbred line,RIL)群体为材料,在5个环境条件下对每角籽粒数性状进行加性QTL、加性×加性上位互作及环境互作分析。【结果】(1)共检测到7个与每角籽粒数相关的加性QTL,主要分布在芥菜型油菜A02、A03、A05、A08、B02和B03等染色体上,其加性效应分布在(-11.6424)~4.5246之间,其中qSS2-71的加性效应和遗传率均最大,分别达到-11.6424和14.44%,其余6个加性QTL的加性效应和遗传率均较小;(2)检测到7对影响每角籽粒数的加性×加性QTL上位互作效应及其与环境的互作效应,上位性QTL互作效应值分布在(-4.9308)~4.1936之间,7对上位性QTL与不同环境互作的遗传力均接近0;(3)每角籽粒数性状的广义遗传率为80.98%,狭义遗传率为30.98%。【结论】综合分析,芥菜型油菜每角籽粒数受一定环境影响,但控制该性状的加性效应受环境影响较小,且其加性×加性上位性QTL互作效应不明显。

[Objective]The study aims to reveal the molecular mechanism of the formation of seed numbers per pod in Brassica juncea L.and Brassica crops,and lay a foundation for improving the yield and breeding of B.juncea.[Methods]In this study,221 recombinant inbred lines(RILs)were engineered using the B.juncea L.We analyzed the additive quantitative trait loci(QTL),additive/additive epistatic effects,and genotype/environment interaction effects on the seed numbers per siliqua in mustard-type rapeseed across five distinct environmental settings.[Results]We identified a total of seven additive QTL associated with the number of seeds per siliqua,predominantly localized on chromosomes A02,A03,A05,A08,B02,and B03 of mustard-type rapeseed.The magnitude of additive effects ranged from-11.6424 to 4.5246,among them,qSS2-71 had the highest additive effect and transmission rate,reaching-11.6424 and 14.44%,respectively.The remaining six additive QTL exhibited less pronounced additive effects and heritabilities.Moreover,the study detected seven pairs of additive/additive QTL interactions influencing the number of seeds per siliqua and their corresponding interactions with the environment.The effects of these epistatic QTL interactions ranged from-4.9308 to 4.1936,with the genetic effects of these interactions across different environments was approximately zero.Broad-sense heritability of the number of seeds per siliqua trait was 80.98%,while the narrow-sense heritability was 30.98%.[Conclusion]Although the number of seeds per siliqua in mustard-type rapeseed is influenced by environmental factors,the additive effects governing this trait appear to be minimally impacted by the environment,and the epistatic QTL interactions are not substantial.