1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Assessment of genetic variability in fodder oats (Avena sativa L.) for yield and quality(Department of Genetics and Plant Breeding , College of Agriculture, Vellayani, 2024-01-08) Annem Sethuvardhan Reddy; Gayathri, GThe current research program, entitled “Assessment of genetic variability in fodder oats (Avena sativa L.) for yield and quality.” involved the study of thirty fodder oat genotypes collected from AICRP Forage Crops and Utilization, Ludhiana Centre under Punjab Agricultural University. This research was conducted in the hill zone at the Regional Agricultural Research Station at Ambalavayal and the plains at the Instructional Farm in College of Agriculture, Vellayani, during Rabi 2022-23. The fodder oat genotypes were evaluated using a Randomized Block Design (RBD) with three replications. The primary objective of this investigation was to assess the genetic variability in fodder oats and develop a selection index for identifying accessions with high yield and nutritional quality. The fodder oat accessions were harvested during the milky stage of grain filling. Quantitative characters like days to first flowering, days to 50% flowering, number of tillers per plant, number of leaves per plant, green fodder yield per plot, dry matter yield per plot, leaf dry weight per plant, stem dry weight per plant, plant height, days to maturity, leaf-stem ratio, ratoon green fodder yield per plot, crude protein content, crude fibre content, total phenolic content, condensed tannin content, total antioxidant content and phytate content were recorded in all accessions. Statistical analyses, such as analysis of variance, genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability, genetic advance, correlation studies, path analysis, cluster analysis and discriminate function analysis were conducted to determine the extent of variation among the existing oat genotypes. The analysis of variance showed significant differences among the studied traits across different genotypes, indicating variability for effective selection. For green fodder yield in the hill zone, the genotypes OL-12, OL-1937, OL-1980, and OL-1963 performed the best with yield ranging from 8.78kg to 8.46kg per plot, while OL-13, OL-1949, and OL-1896 had the lowest yields ranging from 5.75kg to 6.15kg per plot. In case of plains, the highest green fodder yield was observed in JHO-822(3.5kg per plot). Regarding nutritional traits, OL-1931-1 had the highest crude protein content of 16.15 per cent, while OL-1963 had the lowest of 10.97 per cent. Maximum crude fiber content was in OL-1964 (28.02 per cent), and minimum in OL 1952 (15.97 per cent). Total phenolic content was highest in OL-11 and lowest in OL-1963. Condensed tannin content peaked in OL-15, and total antioxidant content was highest in OL 15 and lowest in OL-125. The anti-nutritional character phytate content was lowest in OL-1974 and highest in OL-1976-1. At Instructional Farm, Vellayani, only 12 genotypes managed to reach maturity stage, and their yield was significantly lower ranging from 3.5kg to 2.2kg plot, which was less than 50 per cent compared to the high ranges in Ambalavayal. Among these 12 genotypes, JHO 822 demonstrated superiority in all yield-contributing traits. Genetic variability parameters such as genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability (h2) and Genetic Advance (GA) were studied to find genetic variability present in the genotypes. In the present study, PCV is higher than GCV for all the characters that were recorded, indicating the role of the environment in the expression of these characters. High heritability coupled with high genetic advance was observed for the characters number of tillers per plant, number of leaves per plant, leaf dry weight per plant, stem dry weight per plant, plant height, leaf stem ratio, crude protein content, total phenolic content, condensed tannin content, total antioxidant content and phytate content, which indicates the presence of additive gene action and hence selection based on these characters will be effective for the genetic improvement of the genotypes. The correlation analysis revealed that the trait green fodder yield was correlated positively and significantly with number of tillers, number of leaves, dry matter yield per plot, leaf dry weight, stem dry weight and plant height was correlated negatively and significantly with trait leaf stem ratio. Path analysis divulged that a beneficial positive direct effect on green fodder yield was reported by days to 50% flowering, number of leaves, stem dry weight, leaf dry weight, plant height and days to maturity. While negative direct effect was recorded for days to first flowering, number of tillers, dry matter yield and leaf stem ratio. The residual effect in path analysis (phenotypic) was 0.3644, so about 63% of the total variation in GFY can be explained by the ten characters taken for study. The genetic diversity analysis classified the 30 genotypes into seven clusters following the Euclidean square method, with cluster I being the largest (14 genotypes), followed by clusters II (8 genotypes), IV (3 genotypes), III (2 genotypes), and clusters V, VI, and VII (1 genotype each). The maximum intra-cluster distance was observed in cluster IV, followed by clusters II, I, and III. The highest inter-cluster distance was observed between clusters IV and VII, followed by clusters I and VII. For a successful breeding program, genotypes should be chosen from clusters with the highest degree of divergence. The study found significant genotypic variation for all the examined characteristics. Based upon Selection Index score the genotypes OL-15, JHO-822, and OL-9 exhibited superiority in terms of yield and yield-attributing characteristics, ranking in the top three positions. These superior genotypes can be considered as potential parents for future breeding projects after assessing their combining ability or advanced to further trials for variety development.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 Genetic variability and correlation studies in pumpkin (Cucurbita moschata Poir)(Department of Horticulture (Olericulture), College of Horticulture, Vellanikkara, 1979) Gopalakrishnan, T R; Gopalakrishnan, P KEighteen diverse pumpkin genotypes were grown in a randomized block design with three replications during 1978-79 at the Instructional Farm of College of Horticulture, Vellanikkara to estimate the extend of genetic variability, association among polygenic characters and its partition into direct and indirect effects. A discriminant function analysis was also carried out to find out the efficiency, if any, of selection through discriminant function over straight selection vice versa. The 18 genotypes were significantly different for the 32 polygenic characters studied. The genotype C.M. 17 and C.M.14 emerged as high yielders with other desirable qualities (16.10 kg. and 15.38 kg. fruit yield / plant respectively). Selection of plants considering yield per S E was observed to be efficient than selection of component characters. Fruit yield /plant was positively correlated with length of main vine, average fruit weight and weight of first mature fruit. Leaves /plant and intermodal length had maximum direct effects on length of main vine. Weight of first mature fruit was positively correlated flesh thickness and circumference of fruit. Number of female flowers/plant and number of fruit /plant had no correlation with fruit yield/plant. This aberrant behaviour requires further physiological studies to define the physiological sink in pumpkin. The line C.M.18 is observed to contain the maximum amount of carotene(0.527%) among the 18 genotypes studied. The carotene content was observed rather independent fruit yield /plant.Item Genetic variability and correlation studies in cocoa (Theobroma cacae L.)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1983) Gregory Zachariah; Kumaran, KInvestigation on the generic variability and correlation studies in cocoa were undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during the period from July 1980 to August 1981 in a well established cocoa garden at Alpara in Trichur district, to elucidate information on the extent of variability and the degree of association existing among the 26 important plant, pod and bean characters, in a group of 135 cocoa tress, variety Forastero. Considerable variability was noted among all the characters of the sexually reproduced population of cocoa trees. Number of flowers per unit length on the trunk, number of pods per tree per year, weight of pod, volume of pod and wet weight of beans per pod showed maximum variability. Shell percentage and seed index manifested considerable variability among the bean characters. Phenotypic coefficient of variation (P.C.V.), genotypic coefficient of variation (G.C.V.) and heritability were estimated for 7 pod and bean characters. Both (P.C.V.) and (G.C.V.) were highest for attributes such as thickness of pod husk, number of beans per pod and weight of pod. Moderately high heritability was observed for weight of pod, thickness of pod husk and number of germinated beans. Volume of beans showed the lowest heritability. Yield from trees was found to be positively correlated with 6 of the characters studied, while number of germinated beans per pod and pod value were negatively correlated with yield. Out of the eight characters, pod value had the maximum contribution to yield. Number of pods per tree per year was found strongly associated with yield. Seed index and trunk girth also were positively and significantly correlated with yield. Phenotypic (rp) correlations among seven characters indicated that number of beans per pod was positively correlated with weight of pod. Positive correlations were also established between volume of beans and wet weight of beans per pod. Among the seven characters observed for genetypic (rg) correlations, wet weight of beans showed positive correlation with diameter of the pod and pod weight. Positive phenotypic as well as genotypic correlations were established in the case of wet weight of beans per pod with number of beans per pod and volume of beans. Number of beans per pod in turn, showed positive correlation with weight of pod at both levels. From the present studies it was evident that characters like diameter of pod, wet weight of beans per pod, number of beans per pod, number of germinated beans per pod, volume of pod, volume of bean, pod value, number of cushions on trunk, trunk girth, number of pods per tree per year and seed index have direct influence on the yield of cocoa. These traits can be considered while selecting cocoa trees for using in breeding programmes.Item Genetic analysis of high yielding rice varieties of diverse origin(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Vanaja, T; Luckins C BabuItem Development of tropical gynoecious lines in cucumber (Cucumis sativus L.)(Department of Olericulture, College of Horticulture, vellanikkara, 2016) Karthika, A K; Pradeepkumar, TThe present study ‘Development of tropical gynoecious lines in (Cucumber sativus L.) was carried out at Department of Olericulture, College of Horticulture, Kerala Agricultural university, Vellanikkara, Thrissur during August - November 2014 and February - May 2015 to evaluate the F1 hybrids and their F2 population for identifying stable tropical gynoecious lines of salad cucumber. Twelve hybrids produced by crossing gynoecious line EC 709119 with selected tropical monoecious parents were evaluated for gynoecy under rainshelter. Observations on important quantitative and qualitative characters were recorded. These hybrids were selfed to generate F2 population. F2 population was evaluated for expression of gynoecious character, viz., days taken for female flower anthesis, node at which first female flower emerged and total number of female flowers. The data was subjected to analysis of variance and variability among the genotypes was calculated. Most of the characters exhibited high heritability except for fruit parameters like fruit length, fruit girth and flesh thickness. For gynoecy F2 population from the cross EC 709119 x IC 538186 was observed as the most promising one. This population took only minimum days to form female flower and took minimum number of nodes to form female flower with highest number of female flowers and minimum male flowers. Sex ratio was estimated for parents, F1 hybrids and F2 population. Some of the parents having high sex ratio failed to transmit the same to its hybrid progenies. Among the parents, IC 538186 exhibited highest sex ratio. The highest sex ratio among the F2 population was for EC 709119 x IC 538186. Two populations viz., EC 709119 x IC 527427 and EC 709119 X IC 538186 exhibited a sex ratio of more than 2. The 4 F2 population evaluated for gynoecious trait were classified into monoecious and gynoecious character and tested for goodness of fit based on chi square test with monohybrid ratio of 3:1 being monoecy dominant over gynoecy. Out of the 4 populations, 2 populations were found to express significant value and fit in 3:1 ratio for dominant monoecious trait. The other 2 populations failed to fit in the 3:1 ratio. Bitterness was an important quality character which was absent in most of the parents except three of them during initial harvest. The crosses involving parents prone to bitterness were found to be bitter during later harvest, though all crosses were free of bitterness during initial stage. During later harvests, five parents were found to be bitter. Downy mildew incidence on parents and F1 hybrids were analyzed and Percentage of Disease Intensity (PDI) was estimated. Among parents, IC 538186 exhibited minimum infection and falls under the category of moderate resistance. Hybrid, EC 709119 x IC 538186 exhibited minimum infection and falls under the category of moderate resistance. Among 12 F2 populations, EC 709119 x IC 538186 produced maximum number of true gynoecious plants whereas eight F2 populations failed to produce even one true gynoecious plant. This population also exhibited moderate resistance against downy mildew disease and could be selected for developing true breeding stable gynoecious line for future breeding programme. Present investigation proved the scope of developing tropical gynoecious line from temperate lines by crossing with potential-monoecious lines and making selection in advance segregating generations for gynoecy.Item Heterosis in snakegourd (Trichosanthes anguina L.)(Department of Olericulture, College of Horticulture, Vellanikkara, 1991) Philip Varghese; Rajan, SThe present investigation "Heterosis in snakegourd" was conducted at the College of Horticulture during 1988-1990. Assessment of genetic variability showed significant differences of 25 characters in 48 snakegourd genotypes. The highest phenotypic coefficient of variation was observed for fruiting nodes on main vine, male flowers/plant, sex ratio and fruits/plant. The pcv was lowest for total crop duration. The gcv resulting in high heritability was high for majority of the characters. High heritability coupled with high genetic gain was noticed for male flowers/plant, sex ratio and fruiting nodes on main vine. The 48 genotypes were grouped into 10 clusters. The combing ability analysis revealed significant gca variances for all characters. The sca variances were also significant for all characters. The sca variances were also significant for all characters except for total crop duration, sex ratio and fruits/plant.Item Genetic variability in Chinese potato (solenostemom rotundifolius (poir) J K Morton) for yield and nematode tolerance(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2019) Ankitha, M O; Lekha Rani, CThe present study entitled “Genetic variability in Chinese potato (Solenostemon rotundifolius (Poir) J.K. Morton) for yield and nematode tolerance” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2017-2019, with the objective to identify high yielding Chinese potato genotypes having nematode tolerance. Chinese potato is a minor tuber crop of the tropics in which heavy yield loss occurs due to root knot nematode infestation. The study comprised of two experiments. In the first experiment thirty accessions of Solenostemon rotundifolius (Poir) J.K. Morton, collected from ICAR - CTCRI Sreekariyam, local markets and farmers’ fields of major coleus growing tracts were evaluated for yield and nematode tolerance under field condition. These accessions were evaluated in Randomized Block Design (RBD) with thirty treatments and three replications during August 2018- January, 2019. Analysis of variance was conducted for all the thirteen characters studied. For all characters except for point of tuberization and susceptibility to nematode infestation, ANOVA revealed significant differences among all the genotypes evaluated. The genotype Kenichira local (T17) recorded the highest tuber yield plant-1 (295.37g) followed by CP9 (261.67g), Suphala (258.10g) and CP 8 (254.05g) which were on par whereas the lowest yield of 123.32g was recorded by Thottamkulam local (T10). Minimum days to flowering, maximum number of tubers plant-1 and maximum harvest index were observed for the genotype Kenichira local (T17). High genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were observed for tuber yield plant-1 and harvest index. Thus, selection for these characters would result in improvement of the genotype. High heritability coupled with high genetic advance was observed for number of tubers plant-1, tuber girth, tuber volume, average tuber weight, tuber yield plant-1, biological yield and harvest index. These characters, if selected for, would improve over generations. Tuber yield plant-1 was significantly and positively correlated with number of tubers plant-1, tuber girth, average weight of tubers and harvest index both at genotypic and phenotypic levels. So an improvement in these characters would enhance the tuber yield plant-1. Path coefficients were found out using tuber yield plant-1 as the dependent character and other correlated characters as independent variables. Path analysis revealed that number of tubers plant-1, average weight of tubers and days to flowering had positive direct effect on tuber yield plant-1. Mahalanobis’ D2 statistics was employed to study genetic divergence among the 30 genotypes which were grouped into ten clusters on the basis of relative magnitude of D2 values using Tocher’s method. Cluster I accommodated maximum number of genotypes and in sequence Clusters were having 7, 4, 4, 3,4, 3, 2, 1, 1 and 1genotypes respectively. The maximum inter-Cluster distance was observed between Clusters IV and VII. No close correspondence between geographical distribution and genetic divergence was observed. The second experiment was pot culture study for varietal reaction to root knot nematode. The same thirty genotypes evaluated in experiment I were raised in Completely Randomized Design with three replications during July, 2018 to September 2018. All the pots were artificially inoculated with second stage juveniles of Meloidogyne incognita obtained from pure culture, at the rate of 1000 juveniles plant-1. Nematode characteristics in both soil and root samples were studied. Maximum nematode population in soil was found in the genotype T8 (Parassala local 2). Root-knot index was calculated for each genotype based on scoring method suggested by Heald et al. (1989). According to this scoring method, the genotypes having 0-25 root knots per five gram of root was categorized as resistant. Fifteen genotypes were found to be in the category resistant. The genotype T11 (Pattambi local) showed highest mean values for number of larvae, root knot count, number of females and number of egg masses per five g root. The results of the current study showed the presence of wide range of variability in the thirty Chinese potato genotypes. Characters such as number of tubers plant-1 and average weight of tubers had positive significant correlation and direct association with tuber yield plant-1. Considering superior yield with nematode resistance, Kenichira local ranked first. It was followed by Suphala, CP8 and Edayur local. Kenichira local, CP 28 and Edayur local can be forwarded for further yield trials for variety development.Item Breeding for lodging resistance in rice (Oryza sativa L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2019) Keerthiraj, B; Biju, SThe research work ‘Breeding for lodging resistance in rice (Oryza sativa L.)’ was conducted in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during the academic year 2017-2019. The research work was divided into three experiments. Experiment 1, consisted of screening of twenty-one rice genotypes for lodging resistance which was conducted at Agricultural Research Station (ARS), Mannuthy. After screening, three lodging resistant rice genotypes were selected and crossed in Line x Tester pattern with four lodging prone high yielding varieties, in experiment 2. In experiment 3, progenies were evaluated along with parents for lodging resistance. Lodging and other characters were measured based on Standard Evaluation System of Rice, developed by International Rice Research Institute (SES-IRRI), 2014. Wide variability existed among twenty-one genotypes for yield and most of the yield attributes studied, indicating ample scope for the improvement through selection. High heritability coupled with high genetic advance as per cent of mean indicating the influence of additive gene action in the expression of trait were observed for all the traits viz., days to fifty per cent flowering, plant height, flag leaf width, flag leaf length, tillers per plant, internodal length, culm diameter, culm wall thickness, days to maturity, panicle length, panicles per plant, panicle weight, seeds per panicle, test weight, silicon content, potassium content, seed yield per plant, and lodging per cent. Seed yield per plant recorded positive correlation at genotypic level with number of tillers per plant, number of panicles per plant, test weight, and silicon content. Lodging per cent exhibited positive correlation at genotypic level with days to fifty per cent flowering, plant height, flag leaf length, internodal length, culm diameter, days to maturity, and panicle length. At the same time, it was negatively associated with culm wall thickness, silicon content and potassium content. Based on experiment 1, four genotypes viz., Swetha (L1), Prathyasha (L2), Vaisakh (L3) and Ponmani (L4) were selected as lines. Three genotypes viz., Uma (T1), Gouri (T2) and Pournami (T3) were selected as testers. Evaluation of hybrids based on mean performance revealed that, hybrids H3, H5, H6, H9, and H12 recorded reduced lodging and H7, H8, H10, and H11 recorded moderate lodging. Based on scoring, for all the characters, the hybrids H1 (L1 x T1), H3 (L1 x T3), H5 (L2 x T2), H7 (L3 x T1), H8 (L3 x T2), H10 (L4 x T1), H11 (L4 x T2), and H12 (L4 x T3) showed high values. Estimation of gca effects of parents indicated that, L4, T1 and T3 were better combiners for reduced lodging. Based on all eighteen characters, L4, T1 and T2 were found as better combiners. Considering the scores, of mean performance and combining ability effects for all the characters together, L4, T1, T2, and T3 were found as the most promising parents. Specific combining ability effects studied among the cross combinations and scores indicated that, out of the twelve hybrids, H3 recorded high lodging resistance, and except H1 all others recorded moderate lodging resistance. Based on all the characters considered together, H1, H3, H5, H6, H8, and H10 recorded as better cross combinations. When scores of mean performances and sca effect were considered together for all the characters, hybrids H1, H3, H5, H8, H10, and H11 had high scores, and H6, H7, and H12 scored moderate scores. All the twelve hybrids recorded high significant heterosis for days to fifty per cent flowering, plant height, days to maturity, internodal length and lodging per cent. Scoring for both mean performance and heterotic effect for all the characters, revealed that, the hybrids H12 recorded highest score followed by H10, H11, H8, H3, H5 and H1. Evaluation of hybrids based on scores of mean performances, sca effects and heterosis for all the traits, revealed that, hybrid H10 stands in first position, H8 in second and H11 and H5 in third position. Among these, H10 (Ponmani x Uma) and H11 (Ponmani x Gouri) were found as better cross combinations. The identified hybrids can be evaluated in segregating generations for yield and reduced lodging.Item Characterization of okra [Abelmoschus esculentus L. Moench] genotypes in North Kerala(Department of Plant Breeding and Genetics, College of Agriculture, Padannakkad, 2017) Aswathi G Prasad; Namboodiri Raji Vasudevan