GENETIC AND MOLECULAR ANALYSIS OF FALSE SMUT RESISTANCE IN LANDRACES Of RICE

Abstract

newline A set of total 206 landraces were artificially screened for false smut disease at ICARIIRR farm during Kharif 2020 and Rabi 2021. Out of 206 landraces screened, two genotypes newlineIC126295 and IC379047 were identified as resistant and genotype IC134486 as moderately newlineresistant. Genetic variability, correlation and path analysis among the various quantitative newlinetraits was also carried out. Among the twelve traits studied productive tillers, number of total newlinegrains per panicle and single plant yield exhibited high GCV and PCV. Phenotypic newlineCorrelation results showed the presence of a positive and significant correlation between newlinegrain yield and most of the traits except non-productive tillers and number of chaffy grains newlineper panicle and at genotypic level all the studied characters exhibited high positive and newlinesignificant correlation with grain yield per plant. For disease inheritance study against false newlinesmut, the identified resistance accession IC379047 was crossed with the popular cultivar newlineBPT-5204. The inheritance pattern for the false smut resistance was recorded as 9:7 in F2 newlinepopulation which indicated the presence of complementary gene interaction. Further, QTL newlinemapping for false smut was carried out where two QTLs i.e., qIP2-1 and qSB2-1 were newlineidentified between the marker intervals of A02P10359 - A02P28165 on chromosome 2 with newlineLOD score of 5.34 and 2.72 and contributing 2.56 % and 1.04 % to the phenotypic variance newlineand two QTLs i.e., qIP3-1 and qSB3-1 were identified between the marker intervals of newlineA03P29401 - A03P30243 on chromosome 3 with LOD score of 4.66 and 7.64 and newlinecontributing 1.66% and 2.19 % to the phenotype variance for number of infected panicles and newlinesmut balls. A total of 39 digenic interaction between marker loci and significant positive newlineinteraction between qSB2-1 and qSB3-1 with explaining 10.36% phenotypic variance was newlinedetected in F2 population