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2012 - 20152
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Author: KAU × Author: Lekshmi, S L ×
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    ThesisItemOpen Access
    Development of F1 hybrids of indeterminate tomato (Solanum lycopersicum L.) for protected cultivation
    (Department of Olericulture, College of Agriculture, Vellayani, 2015) Lekshmi, S L; KAU; Celine, V A
    The present investigation entitled “Development of F1 hybrids of indeterminate tomato (Solanum lycopersicum L.) for protected cultivation” was conducted at the Department of Olericulture, College of Agriculture, Vellayani, from 2013 to 2015 with the objectives of identifying superior varieties and developing F1 hybrids of indeterminate tomato suited for protected cultivation. The study consisted of two experiments conducted in the naturally ventilated polyhouse of size 50 m x 20 m located at the Instructional Farm, Vellayani. In the first part of the first experiment, 40 tomato genotypes were evaluated for two consecutive years in an RBD with three replications. As the second part, 12 commercial hybrids were evaluated. The second experiment consisted of a 9 x 9 half diallel analysis laid out in an RBD with three replications. Analysis of variance showed significant differences between the genotypes for all the characters for two crops. Pooled analysis revealed that, LE 1 recorded the highest yield (2443.43 g) and fruit weight (108.13 g) followed by LE 7. LE 53 had maximum number of fruits per plant (65.00). In the present study, genotypes had wide variation for quality parameters. Fruits of LE 14 recorded highest TSS with a mean of 5.74 ºBrix. LE 7 had maximum ascorbic acid (30.13 mg/100g) and lycopene content (13.09 mg/100g). Beta carotene value was maximum in LE 16 (184.15 mg/100g). There was minimum incidence of pests, diseases and physiological disorders under protected conditions. Among the 12 hybrids evaluated, INDAM 9802 was the highest yielder (1444.40 g) followed by F1 T 30 (1412.22 g). F1 T 30 recorded maximum fruits per plant (35.66) which was on par with F1 Queen (35.55). Genetic parameters like phenotypic and genotypic coefficients of variation, heritability and genetic advance were studied to assess the genetic variability among the genotypes. High heritability coupled with high genetic advance were observed for characters like truss per plant, fruits per truss, fruit weight, fruits per plant, yield per plant and yield per plot. Path analysis revealed highest positive direct effect for fruit weight (0.3956), truss per plant (0.3558) and fruits per plant (0.3381). Based on D2 analysis the 40 genotypes were grouped into eight clusters. Cluster I was the largest with twenty four genotypes followed by cluster II with ten genotypes. Diallel analysis was carried out using nine parents selected based on genetic divergence and per se performance. The parents were crossed in a diallel fashion excluding reciprocals to obtain 36 F1 hybrids. The study revealed that P5 x P9 had the highest yield (3114.03 g) which was on par with P6 x P8 (3074.37 g) and P1 x P5 (3077.58 g). P1 x P5 had the maximum fruits per plant (103.93). The magnitude of relative heterosis, heterobeltiosis and standard heterosis varied considerably. For yield, relative heterosis ranged from -32.40 to 92.72, heterobeltiosis from -47.14 to 89.54 and standard heterosis from 2.91 to 160.95. The σ2gca and σ2sca ratio indicated that non-additive gene action was predominant for all traits. Among the nine parents, P9 (LE 1), P5 (LE 20) P1 (LE 2), and P2 (LE 7) were superior for yield and yield attributes. The estimates of sca effects indicated that P5 x P9 (LE 20 x LE 1), P6 x P8 (LE 39 x LE 38) and P1 x P5 (LE 2 x LE 20) were the most promising hybrids for protected cultivation. The present study revealed that the genotypes LE 1 and LE 7 and the hybrids INDAM 9802 and F1 T 30 were superior for yield and yield attributes under protection. Based on the mean performance, standard heterosis and sca effects the three potential crosses viz., P5 x P9, P6 x P8 and P1 x P5 could be adjudged as suitable indeterminate tomato hybrids for protected cultivation.
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    ThesisItemOpen Access
    Identification of paprika (Capsicum annuum L) genotype(s) for yield and quality characters
    (Department of Olericulture, College of Agriculture,Vellayani, 2012) Lekshmi, S L; KAU; Sreelathakumary, I
    The experiment entitled “Identification of paprika (Capsicum annuum L.) genotype(s) for yield and quality characters” was conducted at the Department of Olericultue, College of Agriculture, Vellayani, during the period 2011-2012. The study envisaged assessment of genetic variability in paprika and to study the influence of harvest maturity on quality parameters. Fifty three accessions of paprika were collected from different parts of country and grown in the field in RBD with three replications. The analysis of variance revealed highly significant differences among the 53 accessions of paprika for all the characters studied viz., plant height, primary branches, days to flowering, days to maturity, node to first flower, height of node to first flower, fruit length, fruit girth, fruit weight, fruits per plant, yield per plant, pedicel length, fruit: pedicel ratio, flesh thickness, seeds per fruit, flesh: seed ratio, driage, oleoresin, colour, ascorbic acid, capsaicin, bacterial wilt and leaf curl virus incidence. Among the accessions CA 6 recorded highest yield per plant (776.12 g) and CA 12 recorded maximum number of fruits (265.33). Fruit weight was highest in CA 47 (13.43 g). High phenotypic coefficient of variation and genotypic coefficient of variation were observed for yield per plant, fruits per plant, fruit weight and primary branches per plant. High heritability and high genetic advance also observed for these characters. The path analysis revealed that fruit weight, fruits per plant, plant height and primary branches had direct effect on yield per plant. Correlation and path analysis revealed that fruits per plant is the primary component as evident from the positive correlation as well as high direct and indirect effect on yield. Maximum oleoresin content was observed in CA 7 followed by CA 29 and CA 37. CA 2 recorded a high color value with pungency and CA 37 recorded a high colour with low pungency. CA 38 recorded maximum ascorbic acid content. CA 34 and CA 40 had the minimum pungency and CA 10 recorded the maximum pungency. Bacterial wilt and leaf curl virus incidence among the 53 accessions were studied. CA 33, CA 34, CA 35 and CA 47 recorded less incidence of both diseases. Based on Mahalanobis D2 analysis the current genotypes were grouped into four clusters. Cluster I was the largest with 34 accessions, followed by cluster IV with 15 accessions and cluster II with three accessions. Cluster III had only one accession. In the present study maximum divergence was observed between clusters II and IV as shown by their high intercluster distance. The minimum intercluster distance observed between the clusters I and II indicated a close relationship among the accessions. Based on selection index including both quantitative and qualitative characters CA 34 (Local, Dharwad) was ranked first followed by CA 7, CA 6, CA 33 and CA 35. The accessions were genetically catalogued and the result revealed distinct variations among the accessions for vegetative, inflorescence, fruit, seed and quality characters. Quality characters showed significant differences among the accessions and harvest maturity stages. Oleoresin, colour and capsaicin content in the paprika fruits were found to increase as the age of the fruits increased. Ascorbic acid content in the fruits increased from turning stage to red ripe and then declined. On the basis of the present study the high yielding accessions can be grouped into low pungent and pungent paprika. Among the low pungent, high yielding accessions CA 34, CA 33 and CA 35 recorded high colour value also. CA 6 and CA 7 are promising high yielding pungent paprika accessions. These accessions can be utilized for further crop improvement programmes.