1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Intervarietal heterosis in Capsicum annuum L. and evaluation of a set of clustered bell peppers(Department of Olericulture, College of Horticulture, Vellanikkara, 1987) Girijadevi, T; Peter, K VThe present studies ‘Intervarietal heterosis in Capsicum annuum L. and evaluation of a set of clustered bell peppers’ were conducted at the College of Horticulture, Kerala Agricultural University, Vellanikkara during July 1985 - December 1986. The materials for the study comprised of five bell pepper varieties, two hot chillies and their 10F1 hybrids. Evaluation of these materials revealed considerable variation for most of the economic characters. Phenotypic coefficient of variation was maximum for fruits/plant. High heritability coupled with high genetic advance was also observed for frults/plant. The F1 hybrids Involving bell peppers and hot chillies were found suitable for warm humid tropical conditions of Kerala. All the F1 hybrids yielded more than the better parent. The F1hybrids showed desirable heterosis for plant height, primary branches/plant, tap root length, primary roots/plant, days to flower, days to green fruit harvest, days to fruit ripening, fruit length, fruit perimeter and green fruit yield/plant. The F1 hybrid Hungarian Wax x KAU Cluster was the most promising yielding 482.8 g/plant (fruits/plant - 92) followed by Sweet Red Cherry Pickling x KAU Cluster and Hungarian Wax x Pant C-l. Combining ability analysis revealed the preponderance of additive gene action for primary branches/plant, days to flower, fruits/plant and green fruit yield/plant. A preponderance of non-additive gene action was observed for plant height, tap root length, primary roots/plant and days to green fruit harvest, days to fruit ripening and fruit perimeter. Preponderance of additive and non-additive gene action was observed for fruit length. The parental lines were grouped into three and four clusters during first and second seasons respectively, based on Mahalanobis D2 statistics. The line KaU Cluster was found resistant to bacterial wilt. Primary roots/plant was positively correlated with yield. In segregating generations of Hungarian Wax x KaU Cluster and Sweet Red Cherry Pickling x KAU Cluster considerable variation was observed for all the characters studied. Elite clustered bell pepper lines were Identified and progressed.Item Estimation of genetic parameters in green gram (Phaseolus aureus Roxb.)(Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Presanna Kumari, K T; Mary K GeorgeBiometric studies on fifteen divergent green gram varieties (Phaseolus aurreus Roxb. syn. Vigna radiata (L.) wilzeck.) was conducted at the College of Agriculture , Vellayani , during November- January, 1979-80, to estimate the important genetic parameters like mean, range, genotypic and phenotypic coefficientsof variation , heritability, genetic advance and genetic gain and to find out the direct and indirect contributions of various component characters on yield by path coefficient analysis. There were significant differences among the varieties for all characters studied. Genotypic coefficient of variation was maximum for number of branches per plant followed by 100 seed weight and minimum for days to 50 per cent flowering . High heritability estimates were observed for pod length , 100 seed weight, plant height, number of seeds per pod days to 50 per cent flowering and number of pods per plant. Genetic gain was maximum for number of branches per plant followedby 100 seed weight and minimum for days to 50 per cent flowering. The number of branches per plant 100 seed weight, number of pods per plant and pod length had high heritability and genetic gain indicating the presence of additive gene action and hence they can be relied upon in selection programmes.Item Genetic variability, path analysis and stability parameters in sesame(Department of Plant Breeding, College of Agriculture, Vellayani, 1985) Sverup John; Gopinathan Nair, VBiometric analysis in a varietal collection of sesame was undertaken to study the genetic variability, correlations, path analysis and stability parameters. One hundred sesame types were evaluated in replicated trials at Vellayani in uplands during rabi and at Kayamkulam in rice fallows during summer. Genetic variability and correlations were estimated and path analysis worked out independently as both the locations. Location trials for estimating stability parameters were conducted at three places viz. in uplands during rabi at Pattambi and Vellayani and in rice fallows during summer at Kayamkulam. Large values for genotypic coefficients of variation were obtained for characters such as number of capsules on branches, number of capsules perplant, number of capsules on main stem and number of branches during rabi as well as summer. The lowest genotypic coefficient of variation was obtained for number of days to maturity during both rabi and summer. High values of heritability were recorded by seed protein content , seed oil content, height upto first capsule and weight of 1000 seeds under both conditions.Item Induced mutagenesis for delayed flowering and high tillering in guinea grass (Panicum maximum Jacq.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Sudrik Bibhishan Popat; Mareen AbrahamItem Genetic analysis of yield attributes in Cocoa (Theobroma cacao L.)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1993) Homey Cheriyan; Vijayakumar, N KGenetic analysis of yield attributes in cocoa (Theobroma cacao L.) was undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara, Trichur during 1992-93, with an objective to assess the extent of variability present in the population and to get an insight into the genetic behaviour and mode of inheritance of yield and the different yield attributes in cocoa. A total of 244 steady bearing trees consisting of 19 hybrids and 15 parents were taken for the study. Observations were recorded on 16 characters including yield and yield attributes. Statistical analysis of the data led to the following conclusions. Variability in most of the characters followed the same trend in both the hybrid and the parent populations.Item Genetic analysis in red gram (Cajanus cajan L.)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1990) Achamma Oommen; Narayanan Namboodiri, K MThe research project "Genetic analysis in red gram" was carried out in the College of Horticulture, Kerala Agricultural University, Vellanikkara, Trichur during the period 1985-90. A 5 x 5 diallel cross, excluding reciprocals conducted in red gram revealed the predominance of additive gene effect for all the characters except days to first flowering. The combining ability analysis showed PLA-550 as the best general combiner; and the F 1 of the cross UPAS-120 x I.C. 15708 to have good specific combining ability. Negative heterosis over both the parents was exhibited by UPAS-120 x I.C. 15708 and PLA-550 x PLA-600 for days to first flowering and days to maturity which showed that early maturing segregants could be obtained from these crosses. The same crosses showed relative heterosis for yield also. The analysis of generation means by using six parameter model revealed the importance of both additive and dominance gene effects in the expression of most of the characters. Additive x additive and dominance x dominance effects showed influence in the expression of the characters. Among the components of variances dominance variance was higher for most of the characters. Heritability in narrow sense was found to be low. Number of clusters per plant and number of pods per plant were highly correlated with yield in parents, F 1 's and F2's. As the yield and yield components in the present study were under all the three types of gene action viz., additive, dominance and epistasis, reciprocal recurrent selection procedure seems to be the best suited method of breeding for improvement of this crop.Item Variability and hetrosis in green fruited brinjal(Department of Olericulture, College of horticulture, Vellanikkara, 1995) Sathya Varma, P C; Nirmala Devi,SThe present investigation on “Variability and heterosis in green fruited brinjal (Solanum melongena L.)”was conducted at the Vegetable Research Farm, College of Horticulture, Thrissur during 1992 – 94. Twenty three genotypes of brinjal collected from different parts of the country were grown in a randomised block design with two replications to assess the extent of genetic variability for fifteen characters viz., plant height, plant spread, number of primary branches per plant, days to first flowering, number of flowers per cluster, days to first fruit set, days to first harvest, average fruit weight, total fruits per plant, percentage of productive flowers, fruiting period and fruit yield per plant. The genotypic and phenotypic coefficients of variation, heritability, genetic advance and genetic gain were estimated. Correlation studies and path coefficient analysis were conducted to study the association among yield and its component characters and to estimate the direct and indirect effects of component characters on yield. Based on genetic divergence the 23 genotypes were grouped into five clusters. Seven superior genotypes were selected from these clusters based on their field performance and bacterial wilt resistance. The seven genotypes were crossed in a 7 x 7 diallel pattern to get 21 F1 hybrides. These F1 hybrids were evaluated along with their parents to derive information on general and specific combining ability and heterosis. Significant variation was observed among the genotypes for all the 12 characters studied, indicating scope for improvement. High heritability along with high genetic advance was observed for the characters fruit yield per plant, total fruits per plant, average fruit weight and percentage of productive flowers, indicating the action of additive genes. From the correlation studies, it was observed that yield had positive significant correlation with total fruits per plant, fruiting period, average fruit weight and number of flowers per cluster and negative significant correlation with days to first flowering, fruit set and harvest. Path coefficient analysis revealed that the character total fruits per plant had the maximum direct effect on yield. From the combining ability analysis it was noticed that the parental lines SM 247, SM 246 and SM 6 – 6 were good combiners for yield. The best combination for yield was SM 246 x SM 262 and that for earliness was SM 6 – 6 x SM 141. Significant heterosis was observed in many of the hybrids for most of the characters. SM 141 x SM 262 was the hybrid showing significant positive heterosis for plant height, plant spread, number of primary branches, average fruit weight and fruit yield per plant. Similarly SM 6 – 6 x SM 141 was the earliest hybrid to flower, set fruits and be harvested. This also showed the lowest percentage of bacterial wilt incidence. Another hybrid which showed significant heterosis for total fruits per plant, fruit yield and percentage of wilt incidence was SM 6 – 6 x SM 197. The study of heterosis thus revealed that the three hybrids viz., SM 141 x SM 262, SM 6 – 6 x SM 141 and SM 6 – 6 x SM 197 are promising combinations showing superiority in most of the economic characters considered for the study.Item Varietal evaluation and compatibility studies in sapota (Manilkara achras (Mill). fosberg(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 2003) Rajasekar, P; Laila Mathew, KItem Male sterility and its utilization for crop improvement in ridge gourd Luffa acutangula (L.)Roxb.(Department of Olericulture, College of horticulture, Vellanikkara, 2009) Vijeeth C Hegade; Predeepkumar, TThe present investigation on male sterility and its utilization for crop improvement in ridge gourd is undertaken with the objective of investigating the stability of male sterility in ridge gourd Luffa acutangula (L.) Roxb. and expression of male sterility on combinations with different pollen parents of diverse groups. Micropropagation was effective in maintaining the male sterile line. Standardized protocol was followed for in vitro maintenance of male sterile line. In vitro regenerated plants exhibited stable male sterility all round the flowering season. Pollen fertility found to be zero in all the male sterile plants. Cytological analysis of pollen mother cells revealed normal meiosis in form of tetrad formation and pollen degradation found to be in post meiotic stage. Fourteen ridge gourd genotypes were collected from different parts of the country and evaluated for variability with respect fourteen traits. The genotypes exhibited significant variability for the characters studied. Genotypes were grouped into five clusters based on Mahalanobis’s D2 statistics. Five pollen parents from diverse groups were selected for hybridization with the male sterile female parent. Heterosis values were estimated over mid, better and standard parents. Out of five hybrids, four were male sterile and one was partially fertile. Inheritance of male sterility and restoration of fertility is a complex mechanism and the available information on male sterility is not sufficient to explain this unique mechanism. Available result points towards the presence of partial dominant gene action in controlling male sterility. The pattern of inheritance of male sterility and restoration of fertility can only be explained by studying the F2 and back cross generations and the three way cross involving male sterile hybrids and the pollen parent which restores the fertility.Item G x E interaction of semi- erect cowpea genotypes(Department of Olericulture, College of Horticulture, Vellanikkara, 2005) Ampily, M; Salikutty Joseph