Drought is one of the most important factors to decrease the yield of sunflower.The BC3F2 selected backcrossing introgression lines of oil sunflower population including 45 lines were developed by drought-tolerance screening for yield using Helianthus annuus K55 with excellent comprehensive characters and drought sensitivity as recurrent parent and K58 with drought-tolerance as donor parent.The genotypes of selected backcrossing introgression lines were obtained with the whole genome SSR and SNP markers.QTLs affecting five yield traits were detected under both drought stress and well watered conditions in Hohhot and Wuchuan respectively by one-way ANOVA and Chi-square test based on the Genetic Hitchhiking Effect.The QTLs detected by one-way ANOVA were grouped into three types based on their behaviors:type Ⅰ was the QTLs detected in both watered conditions,including four QTLs affecting hundred-seed weight (HSW) in Wuchuan and two QTLs affecting seed yield (SY) and three QTLs affecting filled seeds per plant (FSP) in Hohhot,which were considered to be able to directly contribute to drought tolerance;type Ⅱ was the QTLs detected only under drought stress,including 30 QTLs in Hohhot and 27 QTLs in Wuchuan;type Ⅲ was the QTLs detected only in well watered condition,including 38 QTLs in Hohhot and 64 QTLs in Wuchuan.There 274 loci were detected by chi-square test,among them 14 loci could be detected by ANOVA and chi-square test simultaneously,which might be the key loci for drought tolerance of sunflower.The results lay a foundation of efficient drought tolerance molecular breeding and provide useful drought tolerance materials for sunflower.%干旱是造成向日葵减产的最主要因素之一.利用综合性状优良的自交系K55作为轮回亲本与抗旱自交系K58杂交构建回交导入系,在干旱条件下进行单株产量筛选,得到45个BC3F2抗旱定向选择导入系.通过全基因组SSR及SNP标记扫描,以方差分析和基于遗传搭车原理的卡方检验对呼和浩特市及武川县两点、两种水分条件下的5个产量性状进行QTL检测.方差分析检测到的QTL根据不同环境下的表达情况分为三类,第一类在两种水分条件下稳定表达,包括武川的4个百粒重QTL及呼和浩特的2个单株产量QTL、3个单株实粒数QTL,这些QTL可能对向日葵抗旱性有直接贡献;第二类受干旱胁迫表达,包括呼和浩特的30个和武川的27个;第三类仅在正常供水条件下被检测到,包括呼和浩特的38个和武川的64个.卡方检验检测到极显著位点274个.用两种方法共检测到一致性位点14个,可能是与向日葵抗旱性相关的关键位点.本研究结果可为向日葵高效抗旱分子育种奠定基础并提供相关材料.
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