Identification of novel QTLs controlling sugarcane smut resistance and yield traits

Abstract

Sugarcane yield depends upon various agro-morphological traits, viz., sugar recovery, stalk number, cane girth, cane height and smut resistance. Identification of Quantitative Traits Loci (QTLs) controlling these traits could greatly help sugarcane breeders in marker-assisted selection of sugarcane lines for various breeding programs. Structure and TASSEL software based integration of genotypic and phenotypic data of 103 sugarcane genotypes was resulted in the identification of eighty seven (87) highly associated alleles (p≤0.05), 34 alleles with smut resistance: 27 alleles with sugar recovery: 13 alleles with cane weight and 20 alleles with each of cane girth and height. The phenotypic variance (R2-values) explained by these linked alleles ranged 3.1-24.6% for smut resistance, 2.67- 22.5% for sugar recovery, 2.81-23.46% for cane height, 2.9-14.34% of cane weight and 1.75-12.8% for cane girth. The varying proportions of phenotypic variance explained by these linked alleles indicated that these traits were controlled by additive genetic effects of multiple genes. It also shows that these traits are the genuine quantitative traits. Moreover, the alleles depicting maximum degree of association for sugar recovery (51-131), cane girth (82-184), cane height (52-121), cane weight and smut resistance (51-145 & 51-146) could help in marker assisted selection of sugarcane lines for these traits.