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Theses

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19953
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Subject: Genetics and Plant Breeding × End date: 1995 × Start date: 1995 ×
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Now showing 1 - 3 of 3
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    ThesisItemOpen Access
    Combining ability in bhindi (Abelmoschus esculentus (L) Moench)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Rajani, B; KAU; Manju, P
    The study was carried out in the Department of Plant Breeding and Genetics, College of Agriculture , Vellayani during 1994-95 to estimate the combining ability of six genetically divergent parental strains of bhindi and their 30 F1 hybrids obtained by crossing the six parents in a diallel pattern. The magnitude of heterosis and nature of gene action governing the yield of fruits and other important yield attributes was also elicited through Hayman's numerical and graphical approach. The combinig ability analysis by the Method 1 of Griffing's (1956) approach revealed that the parent P4 (NBPGR/TCR 864) was the best general combiner for yield and a few yield related characters. Among the hybrids P1 X P4 (NBPGR/TCR 893 x NBPGR/TCR 864) exhibited outstanding s.c.a effects for yield. Non addictive gene action was found to govern days to first flowering number of flowers per plant, length of fruit, girth of fruit, weight of single fruit, weight of fruits per plant and number of seeds per fruit while the remaining characters were governed by addictive gene action.
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    ThesisItemOpen Access
    Gene action and combining ability in grain cowpea (Vigna unguiculata (L.) Walp) in relation to aphid borne mosaic virus resistance
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Smitha, S; KAU; Kamalam, N
    Two lines, five testers and ten hybrids of cowpea were evaluated in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 94-95, with the objective of estimating the combining ability of parents and gene action involved in the inheritance of different yield attributes and CAMV resistance. The lines and testers were selected based on their previous performances and crossed in line x tester manner to get ten hybrids. Observations were made on ten characters, of which nine characters showed significant difference among the 17 treatments. It was seen that nonadditive gene action was predominated for the inheritance of number of pods/plant, number of seeds/pod, 100 - seed weight and seed yield/plant and aphid borne mosaic resistance and additive gene action for days to flowering, days to maturity and number of branches/plant. The varieties Pournami, V - 317, V - 276 and Charodi were the best general combiners and the cross combinations V - 317 x CO4 and V-276 x Pournami were the best specific combinations for yield and CAMV resistance. Hence they can be utilized for further crop improvement programme.
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    ThesisItemOpen Access
    Genetic analysis of productivity and quality parameters in ricebean (Vigna umbellata [Thunb] Ohwi & Ohashi)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Suresh Kumar, N S; KAU; Nair, N R
    A study on the variability, correlation and path coefficient analysis was undertaken in 21 varieties of ricebean along with the cooking qualities. The study was conducted at the Department of Plant Breeding, College of Agriculture, Vellayani during kharif 1993. The varieties showed significant difference in all the characters studied except number of primary branches, pods/plant and seeds/pod. Genotypic coefficient of variation was maximum for haulm yield and minimum for days to maturity. At genotypic level grain yield per plant showed positive correlation with plant height, number of primary branches, pods/plant, seeds/pod, days to maturity, nodule weight and protein content. High heritability estimates were observed of 100 seed weight, protein content, root weight and haulm yield. High genetic advance with high heritability was observed for haulm yield, root weight and protein content indicating the presence of additive gene action. Path coefficient analysis indicated that number of primary branches, pods/plant, days to maturity, nodule weight and protein content exerted positive direct effect on seed yield. Cooking quality studies showed that optimum cooking time ranged between 40-70mts, water uptake ranged between 0.79 g/g to 1.2 g/g and volume of extraction ranged between 58.33% to 68.42%. Organoleptic studies revealed that the variety 23Lg is the most acceptable. The study indicated that the model for selection for ricebean varieties should be one with more number of primary branches and pods per plant, more number of days to maturity, high nodule weight and protein content.