Introgression and Mapping of Cotton Leaf Curl Disease Resistance from Wild <i>Gossypium armourianum</i> Kearney into Upland Cotton (<i>G</i>. <i>hirsutum</i>)

Cotton leaf curl disease (CLCuD), caused by the whitefly transmitted geminivirus complex (cotton leaf curl virus [CLCuV] and their satellite molecules), is a serious threat to successful upland cotton production in northwest India and Pakistan. The disease causes significant losses in fiber yield and the quality of cotton. Owing to the regular emergence of resistance-breaking strains of CLCuV, all the previously available CLCuD-resistant germplasms of upland cotton have become compromised, and none of the extant upland cotton cultivars is resistant to this disease. Therefore, alternate sources of CLCuD resistance need to be explored, as genetic resistance is the only pragmatic and tenable management strategy to combat this malady. Here, we report for the first time the introgression and mapping of CLCuD resistance from a related nonprogenitor wild diploid D-genome cotton species, <i>Gossypium armourianum</i>, into upland cotton. A backcross population (<i>G</i>. <i>hirsutum/G</i>. <i>armourianum</i>/<i>G</i>. <i>hirsutum</i>) was developed for this purpose. A single major QTL was found to be associated with resistance to CLCuD and was located on chromosome D01 through the genotyping-by-sequencing technique.