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19883
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Subject: Plant Breeding × Author: KAU × End date: 1988 × Start date: 1988 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Yield and its components in groundnut under partial shade in coconut garden
    (Department of Plant Breeding, College of Agriculture, Vellayani, 1988) Rajasree, M R; KAU; Gopimony, R
    A study on the parameters of variability, heritability and genetic advance and correlation of pod yield with other components were undertaken in thirtyone varieties of groundnut to select genotypes having good yield and adaptability under partially shaded conditions of coconut gardens. The study was conducted during kharif 1987 at the Department of Plant Breeding, College of Agriculture, Vellayani, by raising the varieties in a randomised block design with four replications. Analysis of variance revealed significant differences among varieties for the characters like plant height, first date of flowering , flowering duration, pod yield per plant on fresh weight basis, pod number per plant, mature to immature pod ratio, pod yield per plot on fresh and dry weight basis, 100 pod weight, 100 kernel weight, shelling percentage, halum yield per plant and per plot on fresh and dry weight basis, harvest index, photosynthetic efficiency at reproductive phase, leaf area index at reproductive phase and Cercospora leaf spot disease score. Analysis of variance for chlorophyll-a, b and total pigments revealed that there was no significant difference among the varieties with respect to chlorophyll pigment content. Analysis of variance for shade intensity measured in each plot during vegetative and reproductive phase indicated the presence of uniform shade in the experimental field. High genotypic and phenotypic coefficients of variation, heritability and genetic advance were observed for hundred pod weight and mature to immature pod ratio, suggesting the reliability of these characters during the selection programme for the improvement of this crop. Correlation analysis of dry pod yield per plot with twentyfour characters revealed that fresh pod yield per plot, fresh and dry pod yield per plant, pod number per plant, halum yield per plot on fresh and dry weight basis, harvest index and photosynthetic efficiency during reproductive phase showed relatively high genotypic correlation with dry pod yield per plot. The study indicated that for selecting an ideal plant type of groundnut for partially shaded conditions we have to look for the tallest, earliest flowering and vegetatively maximum vigorous individual plant.
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    ThesisItemOpen Access
    Gene recombination for resistance to bacterial wilt and yield components in brinjal
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1988) Jayalekshmy, V G; KAU; Gopinathan Nair, V
    Brinjal (solanum melongena) is an important vegetable crop of India. It's cultivation is threatened by the bacterial wilt disease caused by Psuedomonas solanacaarum in many places. The cultivation of resistant high yielding varieties is the only effective method of controlling the disease. But the assocation of bacterial wilt resistance with poor yield has obstructed conventional breeding approaches aimed at, deriving useful' recombinations. The present study explores the possibility of developing a resistant high yielding variety by selection in the segregating generation of inter varietal crosses. The plants of the crosses between three resistant varieties, SM-6, SMI-10 and Pusa purple cluster with the susceptable variety Pusa purple long as the male parent, were selfed. The seeds were sown and seedlings raised under two environments, (i) in the field where there is chance for natural incidence of bacterial wilt. (2) in pots with sterilised soil under healthy condition, in both the experiments, mean, variance and correlation coefficients of yield and yield contributing characters were estimated. Study of f2 variability has revealed that, the characters plant height number of fruits per plant and weight of fruit are governed by polygenes. The characters, number of days to first harvest, number of days to final harvest and weight of fruits per plant were governed by major genes with late bearing and low yield dominant over early bearing and high yield respectively. Comparison of means and variances under healthy and infected condition gave an insight into the influence of selection on the expression of these characters. Natural selection for resistance eliminated the early bearers and high yielders leading to directional selection in favour of late bearers and poor yieldes.
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    ThesisItemOpen Access
    Genetic analysis of open pollinated seed progeny of guinea grass clones
    (Department of Plant Breeding, College of Agriculture, Vellayani, 1988) Sally Joseph, V; KAU; Gopimony, R
    Open pollinated seeds collected from six guinea grass clones were used for genetic evaluation of progeny through analysis of variance and covariance, coefficient of variation, heritability, genetic advance, simple correlation studies and D2 analysis. The progeny of pubescent clones were found segregating into pubescent and glabrous types indicating the possibility of producing superior hybrid guinea grass clones using glabrous the character as marker gene. The study on the mean performance of individual traits revealed the overall superiority of the mutant clone MC-16 over others in green fodder yield, tiller counts, leaf-stem ratio and dry matter yield. But MC-2, which was on par with MC-16 in green fodder yield, was found superior over MC-16 in quality characters like crude fibre content and crude protein content. The estimates of GCV and PCV were low for all characters. Among the nine characters studied the highest estimates of GCV and PCV were obtained for dry matter yield indicating scope for improvement of that character through selection. Highgest fodder yield showed positive correlation with all the other characters except leaf-stem ratio and inflorescence count. Dry matter yield was found contributing maximum towards green fodder yield. Plant height and tiller counts have also shown positive correlation with green fodder yield. The data on interrelations among different characters have shown that the different characters have shown that the different associations among tiller counts, dry matter yield, plant height, width of leaves and crude fibre content were positive. This has suggested the possibility of simultaneous improvement of these characters in a selection programme involving any one of these traits. Through divergence analysis of the six varieties were grouped into three genetic constellations with the assumption that the varieties within the cluster had smaller D2 values among themselves than varieties between the clusters. The intercluster distance was maximium between cluster II and III showing considerable genetic distance between these groups. The inflorescence count contributed maximum towards divergence followed by crude protein content, tiller counts and height of plants indicating that selection of parents differing in these characters will result in the production of divergent material.