Genomic Characterization of Modern Sugarcane (Saccharum spp) Cultivars in Terms of Drought Tolerance Using Microsatellite Markers.

ABSTRACT

Genomic characterization of modern sugarcane (Saccharum spp) cultivars in terms of drought tolerance using microsatellite markers

V.Sharma^1*, N.S.Gracia¹, M.de.A.Silva¹, J.L.Jifon¹,  and J. A. da Silva¹

Texas AgriLIFE Research , Texas A&M University system, 2415 E. Hwy. 83, Weslaco (TX), 78596

*Corresponding author: vsharma@tamu.edu

Population based association studies in crops that were established by domestication and early breeding, can be a valuable basis for identification of QTLs. A case control design in a population is an ideal way to identify maximum candidate sites contributing to a complex polygenic trait like drought. In the current study, we identified marker loci associated with drought related QTLs in sugarcane (Saccharum spp), one of the most complex crop genomes, with its polyploidy nature (>8), chromosome number (>100) and interspecific origin. Using 55 microsatellite markers, we have scored 39 polymorphisms among 80 modern sugarcane genotypes. Homogeneity of the population was confirmed through random genomic microsatellite markers. Phenotypic data to evaluate drought tolerance among the genotypes was collected by measuring chlorophyll content, chlorophyll fluorescence, leaf temperature and relative water content. Generalized linear model in SPSS was used to find association between marker loci and phenotypic data. Significant association (0.05 level) has been obtained between 15 marker loci and physiological parameters.