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Subject: Plant Breeding × Author: Biswas, Ardita × Start date: 2013 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    EMS and Gamma ray induced quantitative variation in black gram (Vigna mungo (L). Hepper)
    (AAU, Jorhat, 2021) Biswas, Ardita; Sarma, Akashi
    An investigation was carried out with black gram (urdbean) genotype SBC-40 to determine the effects of gamma rays (250Gy, 300Gy, 350Gy, 400Gy, 450Gy and 500Gy) and ethyl methane sulphonate (0.2%). The data was collected on seed germination and survival percentage, shoot length, root length, fresh weight, dry weight in the first generation i.e. in M1 generationThe LD50 value was recorded at 456Gy and GR50 value was recorded at 362Gy for shoot length and 372Gy for root length. The progressive reduction in germination and survival percentage with increasing doses of gamma radiation was observed in the mutagenic treatments. In M2 and M3 generations, the traits viz., days to 50% flowering, days to pod initiation, days to maturity, plant height, number of branches, number of clusters per plant, number of pods per cluster, pod length, number of seeds per plant, hundred seed weight and seed yield per plant were calculated to estimate the genetic variability, character association, path coefficient, mean performance of the genotypes among the nine treatments of black-gram genotypes for eleven quantitative characters. Analysis of genetic variance revealed moderate to high level of genetic variability among all the genotypes in majority of the characters. High to moderate PCV and GCV were recorded for the traits viz., seed yield per plant, number of clusters per plant, number of pods per plant, plant height and number of branches per plant. The high heritability along with the genetic advance as per cent of mean was recorded in 100 seed weight, clusters per plant, plant height and branches per plant and seeds per pod in M2 generation and in M3, the traits viz., branches per plant, number of clusters per plant, number of pods per plant recorded high heritability along with high genetic advance. In M2 and M3 generations, variation in leaf arrangement like pentafoliate and hexafoliate were observed in different treatments along with variation in leaf colour, leaf shape and structure.Correlation studies showed that seed yield per plant exhibited positive significant association with the traits viz., days to 50% flowering, days to pod initiation, days to maturity, clusters per plant, pod length and 100 seed weight.Path coefficient analysis identified that 100 seed weight, days to pod initiation, clusters per plant and pod length had positive direct effect and indirect effect via days to 50% flowering, seeds per pod, days to maturity and branches per plant. Hence, simultaneous selection of the above traits would be more rewarding to bring improvement in black-gram.