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ThesisItem Open Access Combining ability in vegetable cowpea(Department of Plant Breeding, College of Agriculture, Vellayani, 1992) Rejatha, V; KAU; Ramachandra Nair, NA 6 x 6 diallel analysis was conducted at the Department of Plant Breeding, College of Agriculture, Vellayani, during 1990, aimed at analysing the combining ability, gene action and heterosis of six vegetable cowpea (Vigna unguiculata var-sesquipedalis) lines collected from the germplasm maintained in this department. The experiment I consisted of crossing the six parental lines in all possible combinations, without reciprocals. The material for experiment II consisted of the six parental lines and fifteen hybrids. They were grown in a Randomised Block Design with three replications.The combining ability analysis was carried out based on method 2 under model I as suggested by Griffing (1956). The treatments showed significant differences in most of characters except number of pods/plant and fruit yield/plant. The variance due to general combining ability was significant and higher in magnitude than specific combining ability for the characters days to flowering, mean weight of pod, mean length of pod, number of seeds/pod, length of internode and seed/pod ratio. It was found that the parent selection 104 and selection 145 were the best general combiners for most of the characters studied. The parent selection 129 was the best general combiner for earliness. The hybrids selection 145 x selection 129 was the best specific combiner for mean weight of pod and number of seeds/pod. The hybrid selection 145 x kurutholapayar was the best specific combiner for earliness. The significance of g.c.a. and s.c.a. variances for most of characters indicate the importance of additive and non-additive gene action in controlling the inheritance of these characters. But additive gene action played a major role suggesting that improvement could be made through selection. Heterosis was calculated over mid and better parental values. Maximum positive heterosis was found for the character fruit yield/plant. Since considerable heterosis was evident in most of the characters, heterosis breeding can be attempted in cowpeaThesisItem Open Access Induction of polyploidy in kacholam(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1996) Ajithmohan, N K; KAU; Pushkaran, KA trial on induction of polyploidy in Kaempferia galanga L. was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during the period 1994-'95. A local selection Vellanikkara collected from the genetic stock maintained at AICRP on M & AP was used for the study. The objective was to create variability in kacholam by developing polyploids. The rhizomes of the crop were treated with colchicine for inducing polyploidy. Five concentration of colchicine viz., 0.05, 0.15, 0.25, 0.35 and 0.45 per cent (C2 to C6, C1 being control i.e., 0%) was tried for two time durations viz., four hours and six hours (T1 and T2), the same treatment being repeated on two consecutive days. Two methods of treatment were tried the first (M1) being chemical application in a hole drilled close to the sprouting bud and the second (M2) being the ordinary cotton swab method. Rhizomes with two different stages of bud sprouting were used: (1) with just emerging buds (S1) and (2) buds at an advanced stage of sprouting (S2). The treated rhizomes were planted in the field and their growth was examined. In the end of the crop season, 18 variant plants were identified and they were put to detailed morphological and cytological study in the next growing season. Mitotic study of the parent material confirmed that the chromosome number of kacholam is 55. Of the 18 variants identified one was found to contain 110 chromosomes in the somatic cells. As kacholam is proposed to be a pentaploid the induced polyploid must be a decaploid. The polyploid was obtained from the treatment combination S1M1T1C6. It was characterised by small plant size and reduced vigour. The leaves were thick with reduced size. Stomatal size increased conspicuously with their numbers reduced. The rhizome development was found retarded and the per plant yield was also less. The rhizome morphology was on par with the normal plants. The plant flowered neither in the first season nor in the second. In addition to the polyploid, there other stable variants were obtained from the experiment. They were also characterised by reduced vigour and yield.ThesisItem Open Access Analysis of Maturity related Characters and Identification of Early Maturing Varieties in Groundnut(Department of Plant Breeding, College of Agriculture,Vellayani, 1990) Sunil Kumar, A C; KAU; Sverup JohnWith the intention of identifying suitable superior early maturing genotypes for intensive cultivation in the summer rice fallows of Kerala, a study was conducted for determining the time of optimum physiological maturity of twelve bunch type groundnut genotypes by analyzing the various maturity related component characters in staggered harvests. The twelve test genotypes and the yield and duration checks were staggered harvested at 70, 80, 90, 100 and 110 DAS. The characters that were put to study in each harvest included the height of plant, number and percentage of mature pods, pod yield, 100 pod weight, 100 kernel weight, shelling percentage, percentage of sound mature kernels, haulms yield, harvest index and oil percentage. Analysis of the various parameters in different genotypes indicated that peak pod yield and time of optimum maturity were closely associated with peak performances of components like number of mature pods, 100 pod weight, 100 kernel weight, sound mature kernel percentage and shelling percentage. It was also noted that the genotypes gave fairly high oil percentage at the time of optimum maturity. The genotypes IES 882, IES 883. IES885, ICGS(E) 21, ICGS(E) 52, ICGS(E) 121, Dh(E) 20 and Dh(E) 32 attained optimum physiological maturity at 90 DAS due to attainment of peak values for the various maturity related component characters. A critical appraisal however showed that the genotypes ICGS (E) 52 and IES 883 exhibited significantly superior performance over the remaining genotypes and the yield and duration checks at 90 DAS. The genotypes ICGS (E) 52 and IES 883 may be recommended for intensive cultivation in the summer rice fallows of Kerala owing to realization of high yield and yield attributes, combined with early maturity. ICGS (E) 52 ranked first with a pod yield 12.85 g per plant, 100 pod weight of 88.6 g and 100 kernel weight of 38.1 g. The genotype IES 883 stood second in performance with a pod yield of 12.00 g per plant, 100 pod weight of 88.3 g and 100 kernel weight of 36.2 g. Both the genotypes exhibited appreciably high performance for shelling percentage and sound mature kernel percentage also.ThesisItem Open Access Combining ability for yield and drought tolerance in cowpea(Department of Plant Breeding, College of Agriculture,Vellayani, 1993) Anilkumar, S G; KAU; Sreekumar S G, S GA research programme was carried out at the Department of Plant Breeding, College of Agriculture, Vellayani during 1991 to 92 with five lines, three testers and their fifteen F1s'. The data on sixteen characters were collected and subjected to line x tester analysis for estimating combining ability and gene action in the inheritance of drought tolerance, yield and related characters. Analysis showed that the line DPLC-198 had a positive and significant gca for leaf area index, grain filling period, number of pods per plant, hundred seed weight, grian yield per plant and biological yield. The line IC-38956 showed negative and significant gca for duration upto first flowering and duration upto maturity. The line DPLC-216 had positive and significant gca for grain filling period and hundred seed weight. The line V-240 for number of seeds per pod and VCM-8 for duration upto maturity showed significant gca. The tester C-152 showed significant positive gca for number of seeds per pod, grain yield per plant and biological yield and showed significant gca for duration upto maturity. The tester Chharodi-1 showed significant negative gca for duration upto first flowering and duration upto maturity. The tester Kanakamany showed significant positive gca for grain filling period, hundred seed weight and biological yield. DPLC-198 x chharodi-1 and IC-38956 x C-152 showed significant and negative sca for duration upto first flowering while DPLC-198 x Kanakamany, IC-38356 x Chharodi-1 and VCM-8 x Kanakamany showed significant negative sca for duration upto maturity. Significant negative sca for proline content was recorded by IC-38956 x C-152, V-240 x Chharodi-1 and DPLC-216 x Kanakamany. DPLC-216 x C-152 and DPLC-216 x Kanakamany recorded significant positive sca for filling period. A significant positive sca for number of pods per plant, grain yield per plant and biological yield was recorded by DPLC-198 x C-152. Leaf area index, number of seeds per pod and hundred seed weight which had additive gene action can be improved by selection. Number of pods per plant and proline content had non-additive gene action.Presence of additive and non- additive gene action with preponderance of non-additive gene action was noticed for duration upto first flowering, duration upto maturity, grain yield per plant and biological yield while preponderance of additive gene action was noticed for grain filling period. The characters that are controlled by non-additive genes or predominantly under the control of non-additive gene can be improved by recurrent selection and recombination breeding. Based on the gca estimates the lines DPLC-198 and IC-38956 and the testers C-152 and Chharodi-1 and the hybrids such as DPLC-198 x C-152, DPLC-198 x Chharodi-1, IC-38956 x C-152 and IC-38956 x Chharodi-1 were recommended for further utilization. Exploitation of heterosis normally is not a viable proposition in cowpea in the absence of easy methods of large scale production of hybrid seeds.ThesisItem Open Access Morphological Effect of Gamma Rays and EMS on Winged Bean [Psophocarpus tetragonolobus (L.)](Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1993) Reeja Dharan, S; KAU; Kamalam, NSeeds of winged bean [Psophocarpus tetragonolobus (L.)] variety PT-62 were subjected to induced mutagenesis using six doses of gamma rays (100 to 500 Gy) and six doses of EMS (40 to 200 mM) to obtain information on the extent of genetic variability that can be induced in the M1 generation. The germination percentage was observed to be decreased by both the mutagens, however the effect was more severe with gamma rays in the field study. But gamma rays caused a stimulation of germination and an earlier germination, at all the doses in the laboratory trials. Number of days taken to complete germination was not much affected by either of the mutagens in the field. The growth of root and shoot were reduced by gamma rays linearly with increase of dose and by EMS drastically at its highest dose, however gamma rays showed greater inhibition of shoot growth and EMS caused greater inhibition of root growth. Survival percentage was observed to be reduced by both mutagens, but EMS was of not much effect. Gamma rays caused a stimulatory effect at its lowest dose. Plant height was beneficially affected by gamma rays at the lowest dose and drastically reduced at higher doses. EMS caused not much variation in plant height. Chlorophyll chimeras and morphological variations were mostly observed in gamma rays treated populations. Morphological variations mostly included alteration in number, size and shape of leaves and size and colour of seeds. Earlier flowering was observed in lower doses of gamma rays, but higher doses caused delayed flowering. Days taken to first flowering was not affected by EMS treatments. Both mutagens exhibited not much effect on the number of days to last flowering. However gamma rays treated populations were in reproductive phase for longer period than EMS treated populations. Number of pods per plant and fruit yield per plant were not affected by EMS treatment. But lower dose of gamma rays caused a stimulatory effect, and thereafter a gradual reduction with increase in dose. Weight and length of pod were slightly increased by EMS treatment, and decreased linearly with increase in dose of gamma rays treatment. EMS caused no significant effect on number of seeds per pod, whereas gamma rays showed an inverse relationship with dose. Both the mutagens showed not much variation in hundred seed weight. Greater pollen sterility was induced by gamma rays treatments, but the effect of EMS was not pronounced. An insignificant increase in seed sterility was exhibited by both the mutagens. In the present investigation greater variability for morphological characters was produced by gamma rays than EMS in the M1 generation of winged bean.ThesisItem Open Access Combining ability studies in tomato (lycopersicon esculentum mill)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Seeja, G; KAU; Chandramony, DAn experiment in tomato (Lycopersicon esculentum Mill.) was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1993-94, with the objective of estimating the combining ability of parents and gene action, involved in the inheritance of different yield attributes. The study was conducted in a line x tester model, using three bacterial wilt resistant varieties as lines and five popular varieties as testers. The three bacterial wilt resistant varieties (lines) were Arka Abha, Arka Alok and Sakthi. The five popular varieties (testers) were LE 312, LE 370, LE 373, RFH-1 and PKM-1. These eight parental varieties and 15 hybrids were planted in the field in RBD, with three replications. Observations recorded were plant height, number of branches/plant, growth habit, spread of the plant, period of harvest, individual fruit weight, number of fruits/plant, fruit yield/plant, number of leaves/plant, pericarp thickness, locules/fruit, size of fruit and pest and disease incidence. Analysis of variance revealed highly significant differences among the genotypes for all the characters. Gca alone was significant for number of branches/ plant while sca alone was significant for spread of the plant and pericarp thickness. Both gca and sca were significant for the remaining characters such as plant height, period of harvest, individual fruit weight, fruits/ plant, fruit yield/plant, leaves/plant, locules/fruit and size of fruit. The additive to dominance variance ratio indicated a preponderance for non additive gene action in the above characters. Combining ability analysis showed that all the three lines viz., Arka Abha, Arka Alok and Sakthi were good general combiners with respect to fruit yield and other yield attributes whereas the testers were good general combiners, for the different vegetative characters such as plant height, branches and leaves/plant. Among the 15 hybrids combinations, significant sca and heterosis were observed in the hybrids such as Arka Abha x LE 370, Arka Alok x PKM-1, Arka Alok x LE 312, Arka Abha x RFH-1 and Sakthi x RHF-1. Among these hybrids, Arka Abha x LE 370 showed significance for fruit yield, individual fruit weight, size of fruit, plant height, leaves/plant, branches/plant and also showed resistance to mosaic, leaf cur1 and fruit borer. This hybrid exhibited indeterminate growth habit. The hybrid Arka Alok x PKM-1 showed significance for fruits/plant, fruit yield/plant, plant height and leaves/plant. The combinations Arka Alok x LE 312 and Arka Alok x RFH-1 showed high sca and heterosis for individual fruit weight, fruit size and pericarp thickness, and also high heterosis for fruit yield/plant. Among these, Arka Aloka 312 showed indeterminated growth and Arka Alok x RFH-1 showed semi determinate growth habit. Sakthi x RFH-1 exhibited high sca for fruit yield/plant and heterosis for fruit number and individual fruit weight. This hybrid also showed resistance to leaf curl and mosaic. This hybrid showed determinate growth habit. Therefore these hybrids can be utilized for further crop improvement programme.ThesisItem Open 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, RA 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.ThesisItem Open Access Genetics divergence in bhindi (abelmoschus esculentus (L.) moench)(Department of Plant Breeding, College of Agriculture, Vellayani, 1993) Bindu, K K; KAU; Manju, PA study was conducted in the Department of Plant Breeding, College of Agriculture, Vellayani during the period 1991-93. The main aim was to estimate the magnitude of genetic divergence in a collection of bhindi varieties to select suitable ones for use as parents for developing commercial hybrid varieties. The estimation of genetic parameters of important economic characters, the association among these characters, direct and indirect effects and D2 values were undertaken. Seventy genotypes of bhindi were evaluated in a RBD with three replications. The genotypes showed significant differences in most of the characters studied except fruiting phase and leaf axil bearing the first flower. Genotypic coefficient of variation was maximum for weight of fruits per plant and minimum for days to first flowering. Heritability estimate was maximum for length of fruit while it was minimum for leaf axil bearing the first flower. Genetic advance as percentage of mean was maximum for weight of fruits per plant. High hertibility coupled with high genetic advance was recorded for length of fruit, leaf area, weight of single fruit, height of the plant and weight of the fruits per plant. At genotypic level yield per plant showed positive correlation with all the characters studied. Path coefficient analysis at genotypic level revealed that the number of fruits per plant, weight of single fruit and number of branches exhibited high direct influence on yield. The study indicated that the model for selection of high yielding varieties of bhindi should be based on the number of fruits per plant, weight of single fruit and number of branches. D2 analysis revealed that the 70 genotypes were grouped into six clusters. Cluster I, II, III, IV, V and VI contained fifty seven, four, three, two, three and one genotypes respectively. The maximum divergence was obtained between clusters II and VI and the minimum between clusters I and IV. The intra cluster distance was maximum in cluster III and minimum in cluster IV. In future breeding programme for the development of heterotic hybrids parent may be selected from cluster II and VI for hybridization.ThesisItem Open Access Induced mutations in interspecific hybrids of abolmochus(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1996) Animon, G; KAU; Gopimony, RThe F1 seeds of the cross between Abelmoschus esculentus cv Kiran and the semi- wild species, Abelmoschus manihot were exposed to four different doses (10, 20, 30 and 40 KR) of gama rays and their effects in the first generation were studied. The percentage of seed germination decreased with increasing doses of gamma rays. The treated hybrids have shown delyed germination compared to the control. The survival of plants was found to decrease with increase in dose of the mutagen. The rate of growth of plants and plant height were found to decrease by the treatment with gamma rays. Various chlorophyll and morphological varients were observed in the irradiated population. An increase in pollen fertility was noticed in the irradiated hybrids. But the increased pollen fertility did not show any effect on the seed set. Irradiation delayed the formation of flowers and fruiting. The mean values for number and weight of fruits did not differ significantly among irradiated treatments and was on par with the control F1. The treated hybrids were found to be on par with the control F1 for yellow vein mosaic disease incidence and the important diseases affecting bhindi. The hybrids irradiated at higher doses had become more susceptiable to fruit borer incidence. The hybrids represented more towards the semi-wild parent and have shown considerable heterosis over the cultivated parent and semi-wild parent for most of the economic characters. The hybrids were vigorous in growth habit compared to the parents. The hybrid treatments exhibited significant positive heterosis for days taken to first flowering and last fruiting over the cultivated parent. The hybrids treatments exhibited significant positive heterosis for number of flowers, number of fruits and weight of fruits over both the parents. Significant negative heterosis over the cultivated parent was shown for fruit length by the hybrid treatments. Significant negative heterosis over the cultivated parent for fruit borer incidence was shown by the control and the hybrids irradiated at 10 and 20 KR. All the hybrid treatments manifested significant negative heterosis over the cultivated parent for YVMD incidence. The mutagenic effectiveness in inducing chlorophyll mutations was found to increase with increase in dose of the gamma rays. The mutagenic efficiency estmated on the basis of lethality and injury increased with increase in dose of gamma rays. On sterility basis, the 30 KR treatments was the most efficient.
