Molecular characterization of genetic basis of Sugarcane Yellow Leaf Virus (SCYLV) resistance in Saccharum spp. hybrid

Sugarcane (Saccharum Spp.) produces 80% of the world's sugar along with other by-products. The production of sugarcane is vulnerable to infestation of sugarcane yellow leaf virus (SCYLV) worldwide. A study was conducted using an F-1 segregating population derived from CP95-1039xCP88-1762 to identify the genetic factors underlying SCYLV resistance. The disease infection data were measured using tissue blot immunoassay after 6 years of exposure to the virus under natural field conditions. Genetic maps were created using genotyping by sequencing-based markers for each parent separately following a pseudo-testcross approach. Two quantitative trait loci (QTL) were detected for SCYLV resistance accounting for 28% of the phenotypic variation. A major QTL qSCYLR79 located on linkage group 79 and linked with marker 3PAV3154 appears to be unique for SCYLV resistance in sugarcane. Progeny having a combination of two major alleles had 31% less SCYLV incidence than progeny with a combination of major and minor alleles in the genomic region of qSCYLR79. Thus, selection against the minor allele may decrease the SCYLV incidence in sugarcane.