Genetic Studies on Abiotic and Biotic Stress Resistance in Maize Zea mays L

Abstract

Maize inbreds with drought and turcicum leaf blight (TLB) resistance were used in newlinethis study conducted at the Department of Genetics and Plant Breeding, College of newlineAgriculture, Dharwad. Thirty one superior inbreds and two testers were crossed in line × newlinetester design to derive 62 test hybrids. Parents, test hybrids and checks (Bio9631, Bio9681, newlineSuper 900M) were evaluated for drought tolerance and yield under stress and non-stress newlineconditions during summer 2016 and 2017. newlineInbreds PDM6529, HKI163 and PDM6576 under stress and HKI163, PDM6518, newlinePDM6529 under non-stress condition were found to be best general combiners while, the newlinecrosses PDM4211 × LM13, PDM6547-1 × LM13 and PDM6547-2 × LM13 under stress and newlinePDM6516 × LM17, PDM6547-1 × LM13 and MLB28-1 × LM13 under non-stress condition newlinewere best specific combiners for traits related to drought tolerance and yield. Mean yield of newlinethe cross PDM4211 × LM13 under stress and non-stress conditions (81.46 q ha-1) was 12.79 newlineper cent superior over best commercial check Bio9631 (72.22 q ha-1). newlineSix generation mean analysis using susceptible (BM125) × resistant (BM135) parents newlineindicated non-additive gene action for TLB resistance. Heterosis breeding approach is suitable newlineto develop resistant hybrids. Of the 146 SSR markers used in the study, three markers viz., newlinebnlg1045, bnlg1940 and mmc0411 were identified to be associated with TLB resistance apart newlinefrom validating the linkage of marker phi109642 with TLB resistance. newlineThe best three general combiners viz., PDM6529, HKI163 and PDM6576 for drought newlinetolerance and yield can serve as donor parents in breeding for drought tolerance these lines newlinecan be crossed in diallele fashion to derive superior hybrids. The test hybrid PDM4211 × newlineLM13 with yield superiority has potential for commercial cultivation. New markers bnlg1045, newlinebnlg1940 and mmc0411 linked to TLB resistance can be utilized in marker assisted selection newlinefor TLB resistance. newline