Genotyping and Association Analysis of Gossypium Hirsutum Lines for Resistance in Reniform Nematodes.

The objective of this research is to perform association mapping in allotetraploid cotton. Molecular marker-assisted selection (MAS) has provided the potential for efficient development of disease and pest resistant plants. Association mapping is used to identify chromosomal regions containing disease-susceptibility loci or loci involved in other phenotypic traits of interest. It has been advocated as the method of choice for mapping complex-trait loci. In cotton, association studies are very limited, although they may be important to improve fiber traits and understand the complex cotton genome along with its evolution. G. hirsutum accessions from the USDA collection were evaluated for resistance to reniform nematodes and genotyped with SSR markers. Most of the SSR markers were polymorphic.  Software STRUCTURE and TASSEL were used to analyze the data. Additional primers should be screened in order to strengthen the association analysis. The results provide preliminary insight into the cotton genome and are very useful as a framework for future ‘association studies’ in cotton that will accelerate development of superior cotton cultivars through a MAS program.