Molecular Characterization and Genetic Diversity Analysis in Bread Wheat (Triticum Aestivum L.)

Abstract

An experiment was carried out to assess genetic diversity at DNA level and at morphological level for yield and its contributing characters in 40 bread wheat genotypes at Technology Park, Meerut, Sardar Vallabhbhai Patel University of Agricultural and Technology, Meerut, (U.P.) in randomized complete block design with 3 replications during Rabi 2017-18. Analysis of variance revealed substantial amount of variability among the genotypes for all the characters under study. The estimate of PCV in all the traits studied were greater than those of the GCV. Considering heritability, most of the characters showed high values. High heritability coupled with high genetic advance (as % mean) were recorded for spike length, grains per spike, biological yield per plant and grain yield per plant, showing that heritability might be due to additive gene effects and direct selection for these traits may be successful. Genotypic correlation coefficients were higher than the corresponding phenotypic correlation coefficients in most of the traits under study. Path coefficient analysis showed that among the different yield contributing characters days to 50% flowering, spikelets per spike, biological yield per plant and harvest index had positive and direct effect on grain yield per plant. The distribution pattern of genotypes in different clusters was random. The highest numbers of genotypes were founded in cluster IV (ten) whereas, cluster I had only one genotypes. The highest intra cluster distance was observed within cluster IV. Highest inter cluster value was observed between cluster I and VII and the lowest inter cluster value observed in cluster between IV and VI. Genotypes from the same geographical region fell into different clusters and vice-versa. This suggested that selection of parents for hybridization should be on genetic diversity rather than on the geographical areas. The SSR markers detected a total of 40 alleles with an average of 2 alleles per locus and the allelic polymorphism information content (PIC) value ranged from 0.09 for WMC 149 to 0.97 for the WMC 224. Resolving power varied from 0.09 to 5.78 with an average of 2.61. These values indictedd a relatively high level of genetic diversity. GS values ranged from 0.47 to 0.95. The dendrogram based on SSR marker analysis grouped the genotypes into six major clusters. These markers are valid and will make a contribution to the studies in hexaploid wheat.