| Summary: | Peanut is susceptible to <i>Aspergillus flavus</i> infection, and the consequent aflatoxin contamination has been recognized as an important risk factor affecting food safety and industry development. Planting peanut varieties with resistance to aflatoxin contamination is regarded as an ideal approach to decrease the risk in food safety, but most of the available resistant varieties have not been extensively used in production because of their low yield potential mostly due to possessing small pods and seeds. Hence, it is highly necessary to integrate resistance to aflatoxin and large seed weight. In this study, an RIL population derived from a cross between Zhonghua 16 with high yield and J 11 with resistance to infection of <i>A. flavus</i> and aflatoxin production, was used to identify quantitative trait locus (QTL) for aflatoxin production (AP) resistance and hundred-seed weight (HSW). From combined analysis using a high-density genetic linkage map constructed, 11 QTLs for AP resistance with 4.61–11.42% phenotypic variation explanation (PVE) and six QTLs for HSW with 3.20–28.48% PVE were identified, including three major QTLs for AP resistance (<i>qAFTA05.1</i>, <i>qAFTB05.2</i> and <i>qAFTB06.3</i>) and three for HSW (<i>qHSWA05</i>, <i>qHSWA08</i> and <i>qHSWB06</i>). In addition, <i>qAFTA05.1</i>, <i>qAFTB06.3</i>, <i>qHSWA05</i>, <i>qHSWA08</i> and <i>qHSWB06</i> were detected in multiple environments. The aflatoxin contents under artificial inoculation were decreased by 34.77–47.67% in those segregated lines harboring <i>qAFTA05.1</i>, <i>qAFTB05.2</i> and <i>qAFTB06.3</i>, while the HSWs were increased by 47.56–49.46 g in other lines harboring <i>qHSWA05</i>, <i>qHSWA08</i> and <i>qHSWB06</i>. Conditional QTL mapping indicated that HSW and percent seed infection index (PSII) had no significant influence on aflatoxin content. Interestingly, the QT 1059 simultaneously harboring alleles of aflatoxin content including <i>qAFTA05.1</i> and <i>qAFTB05.2</i>, alleles of PSII including <i>qPSIIB03.1</i>, <i>qPSIIB03.2</i>, and <i>qPSIIB10</i> and alleles of HSW including <i>qHSWA05</i>, <i>qHSWB06</i>, <i>qHSWA08</i> had better resistance to <i>A. flavus</i> infection and to toxin production and higher yield potential compared with the two parents of the RIL. The above identified major loci for AP resistance and HWS would be helpful for marker-assisted selection in peanut breeding.
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