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ThesisItem Open Access Legume pod borer resistance and genetic divergence in domestic germplasm of yard-long bean (Vigna unguiculata ssp. sesquipedalis(L.) Verdc.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2000) Vidya, C; KAU; Sunny Oommen, KThe present study aimed at the evaluation of variability in domestic germplasm of yard-long bean for yield, and legume pod borer resistance was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Data for the investigation was collected from two field experiments conducted during the period 1998-2000. Fifty diverse genotypes of yard-long bean were evaluated for yield and related characters in a field experiment in randomised block design with three replications. Analysis of variance revealed significant differences among the varieties for all the twelve characters studied. High PCV and GCV were observed for yield of vegetable pods per plant, number of pods per plant, number of pods per inflorescence, length of main stem and pod weight. High heritability coupled with high genetic advance were also observed for these characters. Pod yield per plant showed high positive correlation with number of pods per plant, number of pods per inflorescence, pod weight and length of harvesting period. at genotypic level. Path analysis revealed that number of pods per plant and pod weight were the primary yield contributing characters owing to their high direct effect on pod yield. 2 So selection based on these characters will result in improvement of yield in yard-long bean. Based on Mahalanobis D2 statistic, the 50 cultivars were grouped into four clusters. Cluster I formed the largest cluster with 28 varieties while cluster IV had only a single cultivar. The genetic distance was maximum . ' between clusters I and IV and minimum between clusters III and IV. Cluster I had the highest intracluster distance. The single variety Vs 47 of cluster IV was identified as the highest yielder of green pods. Hybridisation of this variety with varieties having high pod number per plant or pod weight would be beneficial. The cultivars Vs 45 and Vs 49 belonging to cluster III possessed the highest pod weight and pod number per plant respectively. So hybridisation programmes utilising these varieties as parents is worthy of consideration for developing high yielding varieties in yard-long bean. In the field screening programme for legume pod borer resistance all the 50 yard-long bean cultivars were evaluated on the basis of overall plant resistance index (Ipr} computed using a combination of flower, pod and seed damage measurements viz., number of larvae in 25 flowers, percentage pod infestation and seed damage index (computed based on the number of damaged seeds in a sample of 25 pods) respectively. Cultivars showed significant differences among them for these damage . parameters as well as for resistance index computed based on them. The cultivars suffering least flower damage were Vs 5 and Vs 33. Lowest pod damage were recorded for the cultivars Vs 34, Vs 39 and Vs 42. Seed damage index value was the lowest for cultivar Vs 2. 3 Vs 34 with the lowest Ipr value was identified as the most resistant among the 50 yard-long bean varieties. The cultivars Vs 2, Vs 29, Vs 39 and Vs 42 were on par with Vs 34. Correlation analysis of the different damage parameters did not suggest any relationship between flower damage and pod damage or seed damage. However pod damage showed high positive correlation with seed damage. Cluster analysis based on the different damage parameters enabled to group varieties into seven clusters. Based on cluster means of the various damage parameters, cluster IV and I were those suffering least flower and pod damage respectively. So hybridisation programmes utilising varieties from these two clusters could lead to the production of varieties with higher level of legume pod borer resistance. Studies on relationship between pod damage and two pod characters viz., pod wall thickness and fibre content of pods indicated that these pod characters did not influence infestation and damage by legume pod borer. Based on superior yield performance and high level of resistance to legume pod borer, the cultivar Vs 42 is identified as a variety suitable for cultivation in legume pad borer endemic areas. Further, breeding programmes utilising the varieties with high yield and legume pod borer resistance identified in this study could help in evolving better yielding varieties with resistance to pod borer in yard-long bean.ThesisItem Open Access Genetics of bruchid (Callosobruchus sp.) resistance and yield in cowpea(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2001) Jyothi, C; KAU; Kanakamany, M TThe present study 'Genetics of bruchid (Callosobruchus sp.) resistance and yield in cowpea' was undertaken in the Department of Plant Breeding and Genetics, College of Horticulture, Kerala Agricultural University, Vellanikkara. The study was carried out to estimate the various genetic parameters of characters, to identify the yield components, to study association of characters related to pulse beetle resistance and to identify superior genotypes and hybrids having high yield and tolerance to pulse beetle. High variability among parents and hybrids was observed for most of the yield and bruchid resistance traits. The characters namely number of eggs laid, number of adult beetles emerged, number of bore holes produced, loss of weight per seed and tannin content exhibited higher values of heritability, genetic advance and genotypic coefficient of variation, indicating the preponderance of additive gene effects. A positive association was found to exist among yield attributes and also with yield in parents and hybrids. Genotypes having a thicker seed coat showed better resistance to pulse beetle attack and this character was found to be independent in gene action. Kanakamoni among the lines and EC 390231 among the testers were found to be the most promising genotypes for hybridization and selection since they recorded high positive gca. For heterosis breeding the crosses Kanakamoni x IC 201092 followed by C 152 x EC 390231 were found to be superior for pod yield. Kanakamoni and C 152 among the lines and EC 390231 and IC 201092 among the testers showed high tolerance to pulse beetle attack and are recommended for evolving resistant varieties using these genotypes through hybridization and selection. For evolving hybrids showing resistance to pulse beetle the crosses, C 152 x EC 367711 and V 240 x IC 201092 were rated supreme.ThesisItem Open Access RAPD analysis to assess the genetic stability in tissue culture derived black pepper plants(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 2000) Haneesh Babu, T P; KAU; Nazeem, P AAs part of the Post Graduate programme in the Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara experiments were conducted at the Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara during the period from 1997 to 1999; to standardise the method of DNA isolation and the protocol for RAPD analysis in- black pepper so as to assess the genetic stability and clonal fidelity of tissue culture derived black pepper plants. Three methods described by Dellaporta et at. (1983); Doyle- and Doyle (1987) and Rogers and Bendich (1994) were tried. Modification of these methods were tried to find out the effect of grinding the tissue in liquid N2 and use of jJ- mercapto ethanol. The method suggested by Rogers and Bendich (1994) was found better in terms of yield and quality of DNA. Grinding with liquid N2 and use of jJ~ mercapto ethanol was found effective. Tender leaves were found to be the best source for recovery of quality DNA. Different levels and possible combinations of dNTPs, primer and enzyme were tried to standardise optimum levels of reaction components for RAPD analysis of black pepper. Best thermal cycle was identified for the amplification of black pepper genomic DNA. Different concentration of template DNA tried was found not influencing the amplification pattern. Sixty decarner primers were screened for amplification of black pepper genomic DNA. Ten primers selected for good amplification were used to screen five varieties of black pepper. Three primers, which showed polymorphism and stability of amplification, were used for analysis of TC plants. Tissue culture regenerants derived by bud culture were subjected to RAPD analysis using three primers (OPP-l, OPP-8, OPP-14). All the regenerants studied gave a uniform RAPD profile except in two regenerants where there was difference in expression of two non-distinct bands. The present study was effective in optimizing the protocol for RAPD analysis in black pepper and is the first of its kind reported in this valuable spice crop. The primers identified for varietal screening and the RAPD profile developed for the five important varieties can be utilised for fingerprinting of these varieties. The results also ensure the genetic stability and clonal fidelity of the TC plants and the suitability of tissue culture protocol for commercialisation.ThesisItem Open Access Variability in morphological, physiological and biochemical characters in kalmegh (Andrographis paniculata Nees.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2000) Laju Paul, K; KAU; Ibrahim, K KAn experiment ID kalmegh (Andrographis panicu/ata Nees.) was conducted in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara during 1998-2000, with the objectives of understanding the morphological variability, growth pattern, optimum stage of harvest and the variation in different biochemical compounds among the accessions. The accessions were collected from Kerala and neighbouring states. Ten accessions were compared based on 50 morphological, 16 physiological and 3 biochemical characters. In general, accessions showed uniform root, inflorescence, flower and fruit characters. However a limited variation for habit, stem and leaf characters existed among most of the accessions. In general, accessions showed variability for characters namely total plant dry weight, stem dry weight, leaf dry weight and root dry weight when observed at 1, 2, 3 and 4 months after transplanting. Ranking of the accessions was not consistent on the various dates of harvest. Optimum stage of harvest is recommended as 3 months after transplanting. At this stage maximum herbage yield was recorded by accession Ac-4. Physiological parameters namely Leaf area and LAI showed steady increase up to three months after transplanting and thereafter it declined. LAR, RGR, CGR and NAR recorded higher values at earlier dates. Heritability (broad sense) of characters showed inconsistency at various dates of harvest. However leaf dry weight showed higher heritability on all dates. At 3 months after transplanting i.e. the optimum stage of harvest, heritability was high for all the characters relating to herbage yield and most of the physiological parameters. Biochemical studies revealed that the total phenol content and andrographolide content varied considerably among the accessions. Phenol content in the plant increased with an increase in dry weight while Andrographolide content increased with a proportionate increase in moisture content.ThesisItem Open Access Combining ability and heterosis in bittergourd (Momordica charantia L.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2000) Iswara Prasad, C M; KAU; Manju, PThe present investigation "Combining ability and heterosis in bittergourd (Momordica charantia L.)" was conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, involving seven parents, 21 hybrids without reciprocals and the check variety Preethi with a view to assess the general and specific combining abilities, the nature of gene action and to estimate the extent of heterosis for 13 characters in bittergourd. Significant differences were noticed among the 29 genotypes for all the characters studied with respect to the mean performance. Among the parents MC 17 (P,) and MC 40 (P6) and among the hybrids MC 18 x MC 40 (P2 ~ P6) had the high mean performance for yield and most of the yield attributes. The estimates of PCV and GCV for most of the traits were comparatively high with very high estimates of heritability and genetic advance indicating the scope of improvement through selection. The combining ability analys.is revealed that both GCA and SCA variances were significant for all the characters indicating the involvement of both additive and non-additive gene action. However, the ratio of additive to dominance variance was less than unity for most of the characters indicating the predominance of non-additive gene action and thereby suggesting the importance of heterosis breeding programme in crop improvement. The parent MC 40 (P6) and the hybrid MC 18 x MC 40 (P2 x P6) were the best general and specific combiners respectively for yield and most of the yield related components. Several )1ybrids possessed significant relative heterosis, heterobeltiosis and standard heterosis for all the characters except significant standard heterosis for 100 seed weight. The hybrid MC 18 x MC 40 (P2 x P6) recorded the maximum positive standard heterosis for yield and most of the yield attributes. However, the hybrids MC 17 x MC 40 (PI x P6), MC 17 x MC 53 (PI x P7) and MC 18 x MC 53 (P2 x P7) also exhibited good performance with regard to yield and related characters.ThesisItem Open Access Variability analysis of allogamous traits in rice(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2000) Deepa, K P; KAU; Radhakrishnan, V VThe research project entitled "Variability analysis of allogamous traits In rice (Oryza saliva L.)" was carried out in the College of Horticulture, Vellanikkara, Thrissur and the Agricultural Research Station, Mannuthy, Thrissur during the period 1998-99. The major objective of the study was to estimate the amount of variability for floral traits influencing out-crossing in high yielding, local and wild genotypes and CMS lines. It also evaluated the association of these floral traits to out-crossing and identified the genotypes with good morphological traits favouring out-crossing, which can be utilized for restructuring rice flower to suit hybrid seed production. Statistical analysis revealed significant variation in all the 18 characters studied viz, plant height, flag leaf angle, panicle exsertion at flowering and maturity, per cent out-crossing, anther length, filament length, pollen fertility, pollen viability, residual pollen, stigma length, stigma diameter, stigma hair length, angle between stigmatic lobes, stigma exsertion per cent, glume angle, duration of spikelet opening and flowering period in thirty three genotypes of rice. Highest genotypic coefficient and phcnotypic coefficients of variations were observed for STigma exsertion followed by per cent out-crossing and residual pollen. Correlation studies revealed significant positive correlation between out- crossing and the floral traits flag leaf angle and spikelet opening-closing duration. All the traits except residual pollen showed high heritability coupled with genetic gain. Statistical studies showed V20A and V20B, Jaya, Kanchana, Bharathi, Neeraja, Kairali, Nandyar, Chennellu, Oryza longistamina, Oryza oJjicinalis and Oryza spontanea with good floral traits favouring out-crossing.ThesisItem Open Access Evaluation of vegetable cowpea (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt) for legume pod borer, maruca vitrata (fab) resistance and yield(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2000) Pournami Panicker, R; KAU; Sunny Oommen, KThe present study aimed at screening vegetable cowpea germplasm for legume pod borer resistance and evaluation of partially resistant cultivars thus identified for yield was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. Data for the investigation were collected from two field experiments conducted during the period 1997-1999. In the field screening programme for legume pod borer resistance, 51 diverse cultivars were evaluated on the basis of overall plant resistance index (Ipr) computed using a combination of flower, pod and seed damage measurements. The damage parameters employed in the computation of lpr were number of larvae in 25 flowers, percentage pod infestation and seed damage index (Jackai, 1982). Significant differences between cultivars were observed for these damage parameters as well as the resistance index computed based on them. Differences among cultivars in the severity of pod damage assessed as number of entry / exit holes on pod samples were also significant. The cultivar suffering least flower damage was Vs 27. The cultivars Vs 2 and 28 recorded the lowest percentage pod infestation as well as pod damage severity. Cultivar with the lowest seed damage was Vs 13. Lower Ipr values indicate higher levels of plant resistance. Consequently Vs 27 with the lowest Ipr value was identified as the most resistant among the 51 cultivars. Other cultivars on par with Vs 27 were Vs 2, Vs 7, Vs 8, Vs 10, Vs 19, Vs 28, ys 31 andVs35. Correlation analysis of different damage parameters did not suggest any relationship between flower and seed damages. Percentage pod infestation and pod damage severity showed highly significant positive correlation between . them but were uncorrelated with larval count in flowers. Seed damage was found to be positively correlated with pod damage. Despite differences in total leaf chlorophyll content among the cultivars, the correlation between total leaf chlorophyll content and plant resistance index was non-significant indicating the absence of any relationship between them. Similarly peduncle length did not show any relationship with Ipr as well as the different damage parameters. However, pod width was found to be positively correlated with Ipr, pod damage severity and percentage pod infestation. Non-glandular trichome density on pods recorded significant negative correlation with Ipr and pod damage indicating that plant resistance increases with increase in non-glandular trichome density on pods. Fifteen top ranking cultivars with respect to legume pod borer resistance were chosen and evaluated for yield and its components in a field experiment in RBD with three replications. Analysis of variances revealed significant difference among the varieties for eleven out of the fourteen characters studied. The cultivar Vs 14 was the top yielder of vegetable pods with Vs 24 on par with it. Highest pod length was recorded by Vs 28 and highest pod weight by Vs 2. High heritability and genetic advance were recorded for number of pods per plant, yield of vegetable pods per plant and pod weight. Number of pods per plant had high direct effect on vegetable pod yield. Its correlation with yield was significant and positive. This suggested that number of pods per plant is a character important in selection programmes for yield in vegetable cowpea. The cultivars Vs 14 and Vs 24 which were high yielders among the partially resistant accessions were identified as varieties suitable for cultivation in legume pod borer endemic areas.