Kumar, RajeevPankaj, Yaswant Kumar2020-02-282020-02-282019http://krishikosh.egranth.ac.in/handle/1/5810143903The inheritance of tolerance to high temperature stress at grain yield was investigated via a QTL analysis based on 167 doubled haploid progeny of a cross between the cultivar PBW 343 and KSG 1186. Performance data were collected from three different date of sowing in the month of 28 November, 22 December and 15 January, followed by almost one month gap period at the farm of Rajendra Prasad Central Agricultural University, Pusa, Bihar. Significant differences were observed among the genotypes for all the traits under consideration namely grain yield and canopy temperature. Exploitable extent of correlation amongst the entries between both the characters for different date of sowing was present as revealed by considerably higher estimates correlation coefficient up to the value of (R = 0.88). Using composite interval mapping, a total no. of eight QTLs were identified for both the characters viz. canopy temperature and grain yield. QTL.ct2-6B was flanked by the marker barc127-cfd135 was having largest LOD score of 4.36 with the highest phenotypic variance (R2 = 23.28%). QTL.yld2-1A was flanked by gdm33-gwm136 was having the lowest LOD score of 2.54 with the lowest phenotypic variance (R2 = 11.66%). This scenario has indicated that LOD score and phenotypic variance are proportional to each other. Two QTLs viz. QTL.ct1-2A and QTL.ct2-6B related to canopy temperature has sown negative additive effect with the value of -0.92 and -1.20. The reason behind the negative additive effect is the mostly alleles contributing from the poor parent PBW 343 which is susceptible to heat stress. These information's can be used further for fine mapping and marker assisted selection in the near future.ennullThesis