Mapping Cotton Fiber Quality Trait QTLs Using Random-Mated Recombinant Inbred Population.

The objective of this research is to identify molecular markers associated with quantitative trait loci controlling fiber quality traits using a random-mated recombinant inbred (RI) population. Five hundred fifty RILs derived after 6 cycles of random mating of 11 parental varieties were previously developed at USDA-ARS, Mississippi State. About 18000 SSR markers were screened among the 11 parents for their polymorphisms. A total of 1488 polymorphic SSR markers were selected based on their mapped positions, and cover the entire cotton genome. These markers were analyzed among 11 parental varieties and 275 RILs, and revealed 2571 loci. Of them, 1683 are polymorphic loci that cover all 26 chromosomes, and the average marker locus interval is about 1.5 cM. The 550 RILs were planted in Starkville, Mississippi between 2009 and 2011 to obtain fiber quality data. Marker-trait associations were conducted using JMP Genomics and TASSELL software packages. Markers that were identified as associated with fiber quality QTLs were tested in the other 275 RILs to confirm the associations. Detail marker-fiber quality QTL associations will be presented in the conference.