SHARMA, V.K.GHOSH, SAIPAYAN2024-09-242024-09-242023D/AB/408/2018-19https://krishikosh.egranth.ac.in/handle/1/5810214906Thirty two genotypes of chickpea were evaluated for various morpho-biochemical characters and molecular characterization was utilized to screen and select drought tolerant chickpea genotypes. Experimental materials were evaluated in randomized block design with three replications during three consecutive years. Molecular characterization was done by targeted amplification of the genomic DNA using a panel of thirty four primer pairs. Statistical methods and parameters used for deriving inference were analysis of variance, range, mean values, principal component analysis drought tolerance indices. An analysis of variance revealed significant differences among the genotypes for all the characters evaluated during present study. The results were found to be consistent across the years and the interactive effect because of environmental variations during the above mentioned years was found to be non-significant. Among the genotypes evaluated in the present study, ICCX-161047, IVT (MH) C-22970, ICCX-161078 and ICCX-161055 recorded remarkably higher mean performance for biological yield, yield per plant, number of pods per plant, 100-grains weight and harvest index under both drought and normal conditions. Similarly, genotypes like ICCX-161037, ICCX-161055, ICCX-161078, ICCX-161080, ICCX-161085, IVT (MH) C-22957, and ICCX-161100 exhibited superior performance in respect of root length, plant height, root volume, number of nodules per plant under both conditions. Enzyme activity in the genotypes under evaluation with respect to peroxidase, proline and catalase was, in general, found to be higher under drought stress. However, per cent augmentation in peroxidase activity, proline content and catalase activity under drought stress was not found to be related with degree of drought tolerance among the genotypes. Principal component analysis based distribution pattern of chickpea genotypes evaluated for Drought Tolerance Index (DTI), Drought Susceptibility Index (DSI) and Tolerance Index (TI) clearly indicated that the genotypes were accommodated in into two clusters encompassing 16 genotypes in each cluster. Using four candidate genes based 15 synthesized genic microsatellite primers and 19 reported generic microsatellite markers for molecular characterization of a set of 32 genotypes, amplification was successfully achieved with all the primer pairs. Overall 235 alleles were observed including 182 shared alleles and 53 unique alleles. The amplified product size depicted the variation in the length of amplified products and all the primer sets generated one polymorphic amplified product in every genotype. Polymorphism information content (PIC) varied numerically from 0.65 in the case of primer pairs RPCM CAP2 AP2 G IV to 0.93 in the case of primer pair H2I10, with an average of 0.77 among the combinations of primer pairs. Dice similarity coefficient between ICCX-161082 and GNG-1558 (0.5672) as well as between ICCX-161077 and ICCX-161098 (0.5672) was found to be the maximum amongst pair-wise combinations of genotypes. Dice similarity coefficient between ICCX-161082 and GNG-1558 (0.5672) as well as between ICCX-161077 and ICCX-161098 (0.5672) was found to be the maximum amongst pair-wise combinations of genotypes. Results of cluster analysis using microsatellite markers inferred that 15 drought tolerant genotypes identified on the basis of drought tolerance index among 32 chickpea genotypes in the present investigation were clustered together. The genetic composition of 32 chickpea genotypes was found to be admixture of two ancestral components present in different combinations. The molecular profiling of chickpea genotypes, along with the morphological and biochemical screening based on drought tolerant indices helped to categorize and screen out 15 drought tolerant genotypes from among 32 chickpea genotypes under study in screening of genotypes in relation to drought tolerance.EnglishThesis