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ThesisItem Open Access Genetic analysis of productivity in relation to maturity in bunch groundnut(Department of Plant Breeding, College of Agriculture, Vellayani, 1991) Ramakrishnan, M; KAU; Gopinathan Nair, VA preliminary evaluation of 63 bunch type of groundnut revealed that the genotypic coefficient of variation was highest for number of immature pods per plant which indicated the maximum genetic variability for the trait and lowest for oil content which indicated low variability for the trait. High heritability along with moderate genetic advance was obtained for shelling percentage and 100 kernel weight which showed the importance of additive genes in their control. A maturity index was formulated and on its basis the 63 types were classified in to three groups namely, extra early, early and medium. In the extra early group, 100 pod weight and 100 kernel weight were important components for pod yield. In the early group. Number of mature pods per plant, shelling percentage and 100 kernel weight were important components for pod yield. In the medium group, number of mature pods per plant, shelling percentage and 100 kernel weight were important components for pod yield. For oil yield in all the three groups, pod yield and shelling percentage were the important components. Line x Tester analysis with six extra early types as lines and three high productive types as testers indicated predominance of sca variance over gca variance indicating pre ponderance of non – additive gene action over additive for the traits studied. Chico was the best general combiner for earliness and TMV 2 was the best general combiner for pod yield. High yielding extra early recombinants were selected at 80 days after sowing from the 18 Fz populations for further testing and selection.ThesisItem Open 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, Phe 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.ThesisItem Open 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, JA 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.
