Marker Assisted Selection for Nitrogen use Efficiency in Bread Wheat Triticum aestivum L

Abstract

Study was conducted for genetic characterization of bread wheat genotypes, newlinevalidation of reported nitrogen use efficiency (NUE) linked molecular markers, marker newlineassisted selection in segregating generations of bread wheat and to study the effect of newlineQTLs for NUE and NUE attributing traits in the background of popular varieties. Pooled newlineanalysis of variance among 50 genotypes over the two years (during rabi 2016-17 and newline2017-18) exhibited significant amount of variation for all the traits at two levels of newlinenitrogen (50 and100 kg N ha-1). Harvest index and nitrogen utilization efficiency newlinesignificant and positively correlated with NUE at both levels of Nitrogen (N). newlineOut of fifty genotypes, twelve parents were crossed in half diallel fashion and newlineevaluated under 50 per cent N condition. Combining ability studies indicated that the newlineparents namely, 3SATYN9402, K9107, HD2967 and 46IBWSN1005 were the best newlinegeneral combiners and the specific crosses namely, 3SATYN9402 × K9107, newline3SATYN9402 × HD2967, 3SATYN9402 × 46IBWSN1005, 3SATYN9402 × DBW14, newlineHD2967 × 46IBWSN1005 and WH1022 × K9107 as the best specific combiners for yield newlineand NUE related traits. Based on combining ability analysis six cross combinations newlineadvanced to F2 generation. Among six F2 populations evaluated, 3SATYN9402 × newlineDBW14 found to be more promising. newlineTen primers were found polymorphic between parents. Validation by using 44 newlineSSR markers in the three F2 populations showed that the SSR marker wmc720 showing newlinesignificant association with NUE and its related traits in particular and hence, it can be newlineused for improvement of NUE in wheat. Further to pyramid four QTLs, two F2 newlinepopulations {(UAS323 × K9107) and (GW322 × 2WYCYT34)} were intercrossed to newlineobtain F1s. The intercross F1s were genotyped and showed positive for GLN1, m308, newlinewmc162 and gpw7452. Thus, generated intercross hybrids pay the way for development newlineof varieties with enhanced NUE and high yield. newline