甘蓝型油菜叶中控制叶绿素含量性状的QTL定位及其候选基因鉴定

QTL mapping and candidate gene identification for controlling chlorophyll content traits in Brassica napus L.leaves

【目的】定位控制油菜叶片叶绿素含量的QTL,鉴定QTL区间的候选基因,为油菜高光效品种选育提供理论参考。【方法】在2种生态环境测定KN DH群体348份品系叶绿素含量性状,结合KN高密度遗传连锁图进行叶绿素含量QTL定位和QTL区间候选基因鉴定。【结果】在2个生态环境初步鉴定到34个叶绿素含量显著性QTLs,QTL区间整合获得31个叶绿素含量consensus QTLs,其中3个QTLs至少在2个种植环境鉴定到。2个QTL cqCC.A7-3和cqCC.A7-5在冬性和春性生态环境都能够鉴定到,属于冬性和春性环境稳定表达QTL;cqCC.A1-4在冬性生态环境中鉴定到,属于叶绿素含量性状的主效QTL。油菜叶绿素含量QTL置信区间共鉴定到66个潜在候选基因,其功能主要涉及叶绿素的生物合成和降解、光合作用中的光信号和电子传递,包括BnaA01g14880D(ACD1-LIKE)、BnaA07g29990D(AtWSCP)、BnaA01g22670D(LHCA3)、BnaC08g43200D(PSAO)、BnaC06g28800D(FTSH1)和BnaC08g19460D(SAUL1)等。【结论】控制油菜叶绿素含量的QTL定位及其候选基因鉴定可为油菜叶绿素调控基因的精细定位、遗传基础解析以及油菜高光效育种提供基因资源和理论依据。

【Objective】The present paper aimed to provide theoretical reference for the breeding of rapeseed varieties with high photosynthetic efficiency,and QTL mapping of chlorophyll content(CC)and candidate genes within QTL confidence interval were identified.【Method】The chlorophyll content of KN double-haploid(KN DH)population containing 348 lines was investigated under two ecological environments.Based on the KN high-density genetic linkage map and the phenotype data for chlorophyll content,QTLs for chlorophyll content and candidate genes within QTL confidence interval were identified.【Result】Thirty-four QTLs for chlorophyll content were detected.According to QTL integration,31 consensus QTLs were identified,among which three QTLs were detected in at least two plant environments.Two QTLs cqCC.A7-3 and cqCC.A7-5 were identified in winter and spring ecological environments,which were regarded as the environmental stably express QTLs.In particular,one major QTL for chlorophyll content was identified in winter ecological environment and regarded as one major QTL of the winter environmental stably.Sixty-six candidate genes within QTL confidence intervals were detected,and their function involved in chlorophyll biosynthesis and degradation,light signal and electron transport,etc,such as BnaA01g14880D(ACD1-LIKE),BnaA07g29990D(AtWSCP),BnaA01g22670D(LHCA3),BnaC08g43200D(PSAO),BnaC06g28800D(FTSH1),BnaC08g19460D(SAUL1),etc.【Conclusion】QTLs for chlorophyll content and potential candidate genes in rapeseed can provide gene resources and theoretical basis for fining mapping,genetic analysis and high photosynthetic efficiency of chlorophyll content.