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Subject: Plant Breeding × End date: 1991 × Start date: 1991 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Genetic analysis of productivity parameters in horsegram
    (Department of Plant Breeding, College of Agriculture,Vellayani, 1991) Elizabeth, Mathew; Ramachandran Nair, N
    A study on the parameters of variability, correlation and path coefficient were undertaken in forty eight horsegram varieties. The study was conducted at the Department of Plant Breeding, College of Agriculture, Vellayani during Rabi 1989. The varieties showed significant differences in all the characters studied. Genotypic coefficient of variation was maximum for days to flowering and minimum for length of pod. High heritability estimates were observed for hundred seed weight and days to flowering. Genetic gain was maximum for days to flowering. Hundred seed weight and days to flowering recorded high heritability and high genetic gain indicating the presence of additive gene action. At the genotypic level seed yield showed high positive correlation with harvest index and number of pods per plant. Path coefficient analysis projected number of pods per plant, length of pod and number of branches as the traits exerting high positive direct effect on seed yield. The study indicated that the model for plant selection in horsegram should be one with more number of branches, long pods and more number of pods per plant. The varieties P. Palayam, CODB-1, Calicut local, PLS-6056 and No.447 were found to fit in this model.
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    ThesisItemOpen Access
    Genetic evaluation of M2 V1 guinea grass (Panicum Maximum Jacq) clones under partially shaded conditions
    (Department of Plant Breeding, College of Agriculture, Vellayani, 1991) Santhi Priya, G; KAU; Manikantan Nair, P
    he top ranking ten clumps from the open pollinated seed progeny of each of the four mutant clones of guinea grass variety FR - 600 viz., MC - 2, MC - 14, MC - 16 and MC-23 and two control varieties FR – 600 and Makueni were studied in terms of green fodder yield, dry matter yield, tiller count and root length and were evaluated to identify genetically superior clones. The six clones comprising of 60 progenies were evaluated in a field trial in a compact family block design with four replications. Analysis of variance carried out for ten characters revealed significant differences among the six families for seven characters. The familywise analysis of variance carried out displayed significant differences among the progenies in either one or more of the families for eight out of the ten characters, indicating that sexual reproduction is prevalent in the crop at least to some extent. As genetic variability existed within the families, selection will be effective within the families too. Genotypic coefficient of variation was maximum for inflorescence count and minimum for height of grasses. High heritability estimates were recorded for inflorescence count, height of grasses and free proline content of leaves, indicating that its genetic improvement can be effected through selection. Moderate heritability values were recorded for root length, leaf area and dry matter yield while tiller number. Leaf/stem ratio, green fodder yield and reaction to collar rot recorded low heritability values. Genetic advance expressed as percentage of mean was high for free proline content of leaves and inflorescence count and low for all the other characters. A selection index based on plant height, tiller number, leaf area, leaf/stem ratio and green fodder yield identified six of the progenies as genetically superior from among the sixty progenies studied, when ten per cent selection was exercised. The top ranking six progenies belonged to the families MC – 23 and Makueni.
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    ThesisItemOpen Access
    Correlation and path analysis in sesamum (Sesamum Indicum L.) under rainfed conditions
    (Department of Plant Breeding, College of Agriculture, Vellayani, 1991) Kuriakose Conil; KAU; Sreekumari Amma, J
    A research programme was carried out at the College of Agriculture, Vellayani with twentyfive varieties of sesamum during the rabi season of 1989, in order to identify superior sesamum genotypes possessing high oil content and to asses the relationship between yield oil content and to assess the relationship between yield and other plant characters through correlation and path analysis under rainfed conditions in the rabi uplands. The design adopted was a randomised block design with three replications and observations were recorded from randomly tagged plants on 13 plant characters and the major weather parameters. Significant differences existed among varieties with respect to six characters studied. The variety C-6 had the maximum seed oil percentage of 56.96 per cent. The variation in oil content of seeds was largely due to genotypic differences. The highest estimate of 94 per cent heritability was shown by the character oil content of seeds, while the highest genetic advance under 5 per cent selection was shown by the character number of seeds per capsule. At the genotypic level, seed yield was positively correlated with plant height, length of the capsule, breadth of the capsule, root-shoot ratio, number of seeds per capsule, days to first flowering and oil content of seeds and negatively with number of leaves per plant and number of capsules per plant. The oil content of seeds showed positive genotypic correlations with number of seeds per capsule, days to first flowering and seed yield and a negative correlation with root- shoot ratio. Path analysis technique was not found to be satisfactory to explain the direct and indirect effects of plant characters since the residual values obtained were high. The variety ACV-2 ranked first among the five varieties identified as superior genotypes at 20 per cent selection. The expected genetic gain was estimated as 37.25. The maximum amount of drymatter was produced by the variety ACV-1. The variety NPG-3 had the highest amount of proline in its leaves. None of the varieties could be regarded as a 'proline accumulating' genotype. The highest percentage of soil moisture available was at 56 days after sowing. The sesamum crop received the highest amount of 25.5 mm rainfall during the 42nd standard meterological week and the lowest amount of 1 mm rainfall during the 50th standard meterological week.