甘蓝型油菜耐盐和耐旱相关性状的QTL分析

QTL mapping of salt and drought tolerance related traits in Brassica napus L.

盐胁迫和干旱胁迫是非生物胁迫中影响作物产量的重要因素,检测与耐盐和耐旱相关的QTL,可为抗逆油菜品种的选育提供理论依据。本研究利用德国冬性甘蓝型油菜Express和中国半冬性甘蓝型油菜SWU07为亲本构建的包含261个株系的双单倍体(doubled haploid,DH)群体,分别以1.2%NaCl溶液和20%PEG-6000溶液作为培养液模拟盐胁迫和干旱胁迫,去离子水为对照,对2个亲本和DH群体进行发芽试验。播种后7 d测定幼苗根长、鲜重及发芽率,计算各性状在盐胁迫和干旱胁迫下的相对值,并作为评价耐盐和耐旱的指标。根据已构建的遗传连锁图谱进行QTL定位。盐胁迫下,在3次重复中共检测到与盐胁迫相关的QTL 12个,分布在A02、A03、A05、A09、C01和C09染色体上,单个QTL可解释的表型变异为3.61%~10.59%,其中5个QTL在不同的重复中被检测到。干旱胁迫下,共检测到与干旱胁迫相关的QTL 9个,分布在A01、A02、A03、A05、A09、A10和C03染色体上,单个QTL可解释的表型变异为3.94%~12.90%,其中2个QTL在不同的重复中被检测到。此外,在A02和A03染色体上检测到与2种胁迫都相关的相互交叠的QTL。这些结果可为油菜耐盐和耐旱性改良提供更多遗传信息。

Salt and drought stresses are main abiotic stresses affecting crop yield.Detecting the QTLs related to salt and drought tolerance can provide theoretical basis for stress resistance breeding in rapeseed.In this study,a doubled haploid population(DH population),which included 261 lines constructed using the German winter rapeseed cultivar‘Express’(female)and the Chinese semi-winter line‘SWU07’(male),were used to detect QTLs related to salt and drought tolerance.The seeds were germinated in Petri dishes under 1.2%NaCl and 20%PEG-6000,respectively.The control was under the sterile dH2O.Three tolerance related traits,root length,fresh weight and germination rate of each line were measured on the 7th day after planting.The relative value of root length,fresh weight and germination rate under the salt and drought tolerance condition were calculated.Composite interval mapping(CIM)was used to identify the related QTLs according to the constructed genetic map.A total of 12 QTLs were detected for salt tolerance related traits and located on A02,A03,A05,A09,C01,and C09 chromosome,explaining phenotypic variation ranging from 3.61%to 10.59%.Five of these QTLs were persistently expressed in different repetitions.A total of 9 QTLs were detected for drought tolerance related traits and located on A01,A02,A03,A05,A09,A10,and C03 chromosome,explaining phenotypic variation ranging from 3.94%to 12.90%.Two of these QTLs were persistently expressed in different repetitions.In addition,the overlapped QTLs,located on A02 and A03,were detected under salt stress and drought stress.These results provide more genetic information for improving salt and drought tolerance in rapeseed.