genetic and genomic analysis of drought tolerance using doubled haploid lines in tropical maize zea mays l

Abstract

newline Maize doubled haploid lines were developed using six populations which are newlinerelatively drought tolerant and good general combiners for grain yield, at Corteva newlineAgriscience facility at Bangalore during 2016 to 2017. A total of 300 hybrids were newlinegenerated using doubled haploid lines crossed to single known tester. The test hybrids and newlinechecks (DKPDKC 9133, EUAS6668, P3550 and P3401) were evaluated for drought newlinetolerance, yield and yield attributes under well-watered and water stress at flowering newlineconditions during rabi 2018 at Hyderabad and Aurangabad locations (Corteva Agriscience newlineResearch farms). The study was further deep dived to identify QTLs for secondary traits newlineand practiced genomic selection using 3352 SNP markers. newlineThe analysis for variance revealed significant differences among the genotypes for newlinemost of the characters studied. This indicated that, the genotypes under study exhibited newlinesufficient variability which is the basic requirement for selection of superior genotypes. newlineThe combined analysis of variance across locations revealed that out of seventeen traits newlinestudied, twelve were significant for genotype by environment interaction and hence these newlinetraits were further analyzed for stability. newlineA total of 34 hybrids found superior over one of the check hybrids under water newlinestress at flowering conditions for yield of which the hybrids viz., H148, H70, H79, H111 newlineand H145 were identified as high yielding and widely adoptable to both water stress at newlineflowering and well water conditions. The Mean grain yield of 7.82 t/ha was recorded by newlinethe hybrid H 148 under water stress condition which was 19 per cent superior over the best newlinecheck P3550 under water stress at flowering condition. newlineThe QTL analysis revealed that there are 48 QTLs identified using SNP markers newlinefor yield attributing traits under stress for anthesis silking interval, ear weight, ears per newlineplant and chlorophyll content on different chromosomal regions during combined location newlineanalysis. The common QTLs were identified for anthesi