Anil KumarRawat, Vaishali2022-02-262022-02-262021-11https://krishikosh.egranth.ac.in/handle/1/5810182901Wheat (Triticum aestivum L.em. Thell) is one of the world’s largest cereal crop. It occupies high, productivity and the prominent position in the international food grain trade. The development of high yielding wheat cultivars is the main objective of any wheat breeding programme in the world. Identification of better genotypes with desirable traits and their subsequent use in breeding programme and establishment of suitable selection criterion can be helpful for successful varietal improvement programme. Analysis of variability among the traits and the association of particular character in relation to other traits contributing to yield of crop would be of great importance in planning a successful breeding programme. The present investigation was carried out in Rabi season, 2020-2021 at N.E. Borlaug Crop Research Centre, G. B Pant University of Agriculture & Technology, Pantnagar. The experimental material for the present investigation comprised of 200 germplasm accessions along with four checks, namely, HD 3086, UP 2855, WH 1080 and UP 2865. These genotypes were evaluated in Augmented Block Design and observations were recorded for 14 characters viz., days to 75% heading, days to maturity, flag leaf area, peduncle length, number of tillers per meter, plant height, spike length, number of spikelets per spike, number of grains per spike, grain weight per spike, 1000-grain weight, biological yield, grain yield per plot and harvest index. Variance (mean sum of square) was found to be highest for the biological yield followed by grain yield and number of tillers per meter and lowest for spike length. The coefficient of variability was found to be highest for grain yield and lowest for days to maturity. Highest genotypic coefficient of variation was observed for grain yield and lowest for days to maturity. High estimates of heritability in broad sense accompanied with high estimates of genetic advance (GA) as per cent of mean was recorded for the grain yield, which indicated the presence of additive gene effects. Grain yield was positively and significantly associated with the biological yield, number of tillers per meter, harvest index, 1000-grain weight, plant height, flag leaf area, peduncle length, grain weight per spike, spike length, number of spikelets per spike and number of grains per spike and non-significant and negatively correlated with days to 75% heading and days to maturity. The genotypes were grouped into 8 different clusters by non-hierarchical Euclidean cluster analysis. Cluster I had 39 genotypes, whereas cluster II comprised of 27 genotypes, cluster III had 39 genotypes, cluster IV had 4 genotypes, cluster V comprised of 14 genotypes, cluster VI had 37 genotypes, cluster VII had 15 genotypes and cluster VIII comprised of 29 genotypes. The intra cluster distance was maximum for cluster IV (23.27) and minimum for cluster I (13.00). The inter cluster distance was found maximum between cluster IV and cluster VII (92.05) and minimum between cluster I and cluster II (18.62). On the basis of findings of the study, five desirable donors for each character were identified on the basis of character mean. KACHU/SAUAL/3/TRCH/SRTU//KACHU [37 ESWYT-111], HD 3226, K 1805, WH 1182 and PRL/2*PASTOR[36 ESWYT-02] ware found to be most promising donor genotypes for grain yield. These genotypes can be used in future breeding programmes to improve the yield potential of the variety. For other characters, genotypes can be picked up from different groups, formed on the basis of their ranking.EnglishThesis