QTL mapping of some productivity and fibre traits in Gossypium arboreum

Authors: TAYYABA SHAHEEN, YUSUF ZAFAR, MEHBOOB-UR RAHMAN

Abstract: This study explains the construction of an intraspecific genetic linkage map of the A-genome diploid cotton with simple sequence repeat (SSR) and randomly amplified polymorphic DNA (RAPD) markers, using 180 F_2 plants derived from the cross of 2 Gossypium arboreum cotton cultivars (Ravi × Entry-17). Polymorphisms between the 2 parents were detected using 1089 pairs of SSR primers and 520 RAPD primers. In total, 34 pairs of SSR primer-amplified and 18 RAPD primer-amplified polymorphic loci were selected to survey the F2 population. In total, 52 polymorphic DNA fragments were generated and used to construct a linkage map with JoinMap 3.0. A total of 45 loci and 5 phenotypic traits were mapped at a logarithm of odds ratio of >=3.0 on 10 linkage groups. The total length of the map was 346 cM, and the average distance between adjacent markers was 7.7 cM. Chromosome assignments were made according to previous studies. In total, 7 quantitative trait loci (QTLs), including 5 for productivity traits and 2 for fibre traits, were mapped. Identification of these QTLs will set the stage for initiating marker-assisted selection and map-based cloning in cotton.

Keywords: Diploid cotton, Gossypium arboreum, simple sequence repeats, genetic map, quantitative trait loci, fibre, productivity traits

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