PHENOTYPIC AND GENETIC STUDIES FOR IDENTIFICATION OF ELITE CLIMATE RESILIENT PREBREEDING MATERIALS IN RICE Oryza sativa L FROM BACK CROSS POPULATION OF ADTR 45 X APO AND ADTR 45 X WAY RAREM

Abstract

newline The present experiment was conducted using two sets of back crossed inbred line newline(BILs) derived from two crosses viz., ADT(R) 45 x Apo with QTLs qDTY 1.1, qDTY 3.1 newlineand qDTY 4.1 and ADT(R) 45 x Way Rarem with QTLs qDTY 12.1. The BILs and their newlineparental lines were evaluated in an irrigated (EI) as well as two drought environments newline(EII and EIII) to study the nature and extend of variation and stability of genotypes for newlinephysio morphological traits viz., days to 50 per cent flowering, plant height, panicle newlinelength, number of grains per panicle, spikelet fertility per cent, 1000 grain weight and newlinesingle plant yield to identify stable BILs with high yield under both irrigated and drought newlineenvironments. Also, the BILs carrying qDTY QTLs along with a set of genotypes were newlinesubjected to intensive phenotyping for root traits, anaerobic germination tolerance and newlinein vitro screening for drought tolerance to understand the genetic makeup of the newlinegenotypes and to identify elite pre-breeding materials for future breeding programme. newlineThe potentiality of a genotype by measure of mean performance and extent of newlinevariability present in the population revealed that per se performance of the traits were newlinehigh in irrigated environments when compared to drought environments. In spite of huge newlinevariations observed between the irrigated and drought environments, the BILs carrying newlineQTLs have registered less reduction in yield and other contributory traits like panicle newlinelength, number of productive tillers per plant, spikelet fertility per cent and 1000 grain newlineweight when exposed to stressed environments. newlineThe difference between the phenotypic and genotypic coefficients of variation newlinewas narrow for all the traits studied in a both irrigated and drought environments newlineindicating greater contribution of genotype towards the expression of the traits. newlineHeritability coupled with genetic advance as per cent of mean were recorded high for newlinesingle plant yield, number of productive tillers per plant, panicle length, number of grains newlineper panicle, spikelet