| Popis: |
Decoding the genetic mechanisms underlying disease resistance is of great importance for crop improvement. Rice false smut (RFS) is a major fungal disease caused by Ustilaginoidea virens that hampers the grain quality and yield of rice worldwide. It causes 2.8-49% global yield loss depending upon disease severity and varieties grown. In India, the severity of yield loss ranged from 2-75%. Keeping the economic importance of this disease, identification of the genes/QTLs governing disease resistance is of prime importance for the development of the linked markers and cloning of the genes. Here, we report mapping of QTLs using a recombinant inbred line (RIL) population derived from a cross between resistant line, RYT2668, and a highly susceptible variety, PR116. The population was evaluated for rice false smut disease under field conditions for three cropping seasons 2013, 2015, and 2016. A total of seven QTLs were mapped on rice chromosomes 2, 4, 5, 7, and 9 of rice using 2326 single nucleotide polymorphism (SNP) markers. Among them, a novel QTL qRFSr9.1 affecting total smut ball (TSB)/panicle on chromosome 9 exhibited the largest phenotypic effect. The prediction of putative candidate genes within the qRFSr9.1 spanned in 994.1Kb revealed four NBS-LRR domain-containing disease resistance proteins. We identified SNPs/Indels associated with the disease resistance which could be used for accelerating breeding programs using marker-assisted selection. In summary, our findings mark the ‘hot-spot’ region on rice chromosomes along with the identification of disease resistance genes in conferring resistance to the rice false smut disease. |
