Katageri, I.S.Ramesh2019-09-232019-09-232015-11http://krishikosh.egranth.ac.in/handle/1/5810129026Based on four testing trials, in three years, DHBR-25, DHBR-43, DHBR-81, DHBR-161, DHBR-128, DHBR-156, DHBR-20, DHBR-88, DHBR-58 and DHBR-153 recorded significantly higher seed cotton yield than best parent DS-28 (853.56 kg/ha) and commercial check, Sahana (1025.63 kg/ha). The genotype DHBR-20 (1313.78 kg/ha; 24.18 g/tex) recorded significantly higher seed cotton yield with significantly higher fibre strength and on par with commercial checks, Sahana (1025.63 kg/ha; 21.52 g/tex) and MCU-5 (659.49 kg/ha; 23.13 g/tex) on other traits like ginning out turn and boll weight. It indicates the possibility of simultaneous improvement for both seed cotton yield and fibre strength through interspecific hybridization. Using CottonSNP63K array BeadChip, 178 recombinant inbred lines were genotyped. Average success call rate was 70.17 per cent. Among them, 83.26 and 16.73 per cent alleles were in homozygous and heterozygous status respectively. The genetic linkage map constructed with 2188 SNP marker loci segregating in 1:1 ratio in mapping population, covered a genetic distance of 2162 cM with an average marker density of 0.98 cM on each chromosome. The largest chromosome was Chr.D19 followed by Chr.D24 which spans 517 cM with 518 marker loci and 288 cM with 289 loci respectively. The shortest were Chr.A04, Chr.D17 and Chr.D23 each covered 11 cM with 12 marker loci. The largest gap length was observed on Chr.A11 (41.1 cM) and lowest on Chr.D19 and Chr.D22 (3 gaps) with mean of 7.45. Using four season mean data, 295, 137 and 19 QTLs were identified by single marker analysis, interval mapping and composite interval mapping respectively. Their contribution to phenotypic variance range from 7.81 to 14.24 per cent in single marker analysis, 7.59 to 39.49 per cent in interval mapping and 9.29 to 24.82 per cent composite interval mapping. QTLs with higher contribution to phenotypic variation (>10 per cent) are useful in genetic enhancement of yield, yield contributing and fibre quality traits.ennullThesis