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Subject: Plant Breeding × Author: KAU × End date: 2008 × Start date: 2008 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Genetic analysis of segregating generations for yield attributesand resistance to fruit and shoot borer (Earias vittella Fab.) in bhindi (Abelmoschus spp.)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2008) Divya, Balakrishnan; KAU; Sreenivasan, E
    The research study entitled “Genetic analysis for yield attributes and resistance to shoot and fruit borer (Earias Vittella Fab.) in Bhindi (Abelmoschus spp.)” was undertaken during the period 2006-2008 at Department of plant Breeding and Genetics, College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur. The main objectives of this project were to study the nature of gene action governing fruit and shoot borer resistance and yield attributes and to attempt for transfer of shoot and fruit borer resistance to genotypes with desirable yield attributes. Six diverse okra genotypes viz, Arka Anamika, KL9, Salkeerthy, Sel 2, Susthira and AC5 were crossed in a 6 x 6 complete diallel pattern. Thirty crosses were made out of which 24 Fjs were fertile and six interspecific crosses were sterile. Fifteen selected F2S were evaluated for yield attributes and resistance to fruit and shoot borer. High genetic variability, heritability and genetic gain were observed in fruit weight and plant height. Both Fi and F2 of the cross Arka Anamika x Salkeerthy recorded the higher fruit yield than others. Arka Anamika was found to be a good general combiner for fruit number, fruit weight and fruit length. KL9 showed high gca for days to first flowering, intemodal number and fruit weight. Fruit yield was positively associated with number of fruits, number of intemodes, fruit weight and fruit length. Shoot and fruit borer infestation recorded- negative association with plant height, flowering period, fruit number, fruit yield and intemodal length. Overdominance was observed for most of the yield contributing traits. Generation mean analysis for six generations from two crosses viz. Sel 2 x AC 5 and KL 9 x Salkeerthy were carried out and gene action for yield attributes and resistance to fruit and shoot were studied. Duplicate non allelic interactions were observed for most of the traits studied. Complementary epistasis govern the inheritance of fruit borer resistance in the cross Sel 2 x AC 5. Digenic non-allelic interaction model was found inadequate to explain shoot borer infestation. Biochemical analysis indicated the presence of higher levels of phenol and tannin content in fruits and shoots of resistant genotypes. The Fi of the cross Sel 2 x AC 5 was identified as the best hybrid for both marketable fruit yield and resistance to fruit and shoot borer and it also showed field resistance to Yellow Vein Mosaic Virus.
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    ThesisItemOpen Access
    Development and evaluation of hybrids in ivy gourd (Coccinia grandis L. Voigt)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2008) Prabu, R; KAU; Wilson, D
    The present investigation on “Development and evaluation of hybrids in ivy gourd (Coccinia grandis L.Viogt.) was carried out at the College of Agriculture, Vellayani during 2007-2008. The objectives of the study were to develop hybrids in ivy gourd, to estimate genetic parameters, variability among and within families and to identify superior hybrids over the check variety “Sulabha”. Hybridization was carried out between four selected gynoecious and three androecious lines. Based on the mean values of the twelve families and their progenies variability among the families and progenies were studied. Genetic parameters and standard heterosis were also estimated in this study. The family 1(Royappanpatty 1 x Royappanatty local) revealed superiority over the other families for days to flower, first harvest, length, girth number of fruits and fruit yield per plant. The magnitude of variation among the progenies of 12 families revealed the heterogeneous nature of the F1 families. Significant variation among the progenies for vitamin C content was expressed in eight families viz., family 3, 4, 5, 7, 9, 11 and 12. Seven families viz., family 2, 3, 4, 5, 6, 11 and 12 showed significant variations among progenies for days to first flowering. Variations among progenies for fruit length were expressed by the families 2, 3, 4, 6, 9, 10, and 11. The families 4, 5, 8 and 10 showed significant variations for average fruit girth among the progenies. The families 4, 5 and 7 showed variations among progenies for days to first fruit harvest. The families 2, 6 and 8 showed variations among the progenies for girth of fruits. Families 4, 6 and 11 recorded significant variations among the progenies for number of fruits. Families 4 and 6 showed significant variations among progenies for fruit yield per plant. Superior plants can be selected from the families showing significant variation for different characters. Pooled analysis of the data showed significant differences among the progenies for all the characters. The minimum days to flowering was recorded in progeny 1 and 5 of family 1 (Royappanpatty 1 x Royappanatty local) followed by progeny 7 of the same family and progeny 1 of family 3. (Royappanpatty 1 x Karyavattam). The same trend was observed for days to first harvest of fruits. The progeny 1 of family 1 was found to be earliest to take harvest followed by three other progenies progeny 2, 5 and 6 of the same family. Significant variation for average fruit length was observed among the progenies. Progeny 1 of family 1 recorded the longest fruits. The highest fruit girth was observed in progeny 1 of family 4. The progeny 3 of family 3 produced fruits having the maximum weight followed by progeny 3 of family 1. The maximum number of fruits was produced by progeny 4 of family 1. Progeny 1 of family 4 recorded the highest vitamin C content. The highest fruit yield was recorded by progeny 3 of family 1 followed by progeny 1 of family 3 and progeny 3 of the same family. Superior progenies identified for different characters from the hybrid population can be utilized for further improvement. The results of the analysis of variance showed significant differences among the genotypes for all the characters studied. The differences between phenotypic and genotypic coefficients of variation were found to be low in this study indicating the major contribution of genetic component. The highest heritability was estimated for days to first harvest followed by fruit yield per plant, fruit weight, fruit length, fruit girth, number of fruits per plant, days to first flower and vitamin c content. High heritability and high genetic advance estimated for important traits like fruit yield per plant, number of fruits per plant, and fruit weight which indicated the effectiveness of selection. Higher genotypic correlation than the phenotypic correlation observed for most of the characters indicated the reduced influence of environment. The number of fruits per plant had significant positive correlation with yield per plant, fruit length and fruit weight. Average length of fruits, girth of fruits, average weight of fruits and number of fruits per plant exerted significant positive direct effect on fruit yield per plant. Therefore improvement of anyone of these characters would bring out simultaneous improvement of yield. The families showed standard heterosis at varying levels for different characters. In this study mean values of the families were taken for comparison with the standard parent. Compared to the standard check “Sulabha” the hybrid population took more days to flower. However, among the hybrid progenies family 1 took the minimum days to flower and fruit harvest. The families 1 (Royappanpatty 1 x Royappanatty local) and 3 (Royappanpatty 1 x Karyavattam) manifested marginal positive heterosis for fruit length and families 1 (Royappanpatty 1 x Royappanatty local), 2 (Royappanpatty 1 x Vellayani local), 3 (Royappanpatty 1 x Karyavattam) 5 (NBPGR 1 x Vellayani local and) and 6 (NBPGR x Karyavattam) expressed heterosis for fruit girth. The positive heterosis for average fruit weight was observed in the families 1 and 3. The maximum positive heterosis for number of fruits per plant was observed in the family 1 followed by 2 and 3. Nine hybrids expressed positive heterosis for vitamin C content. The heterosis for fruit yield per plant was the maximum in family 1 followed by 3 and 2. The superior progenies identified for different characters from the hybrid population can be utilized for further improvement.
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    ThesisItemOpen Access
    Genetic variability for yield and resistance to chilli thrips (Scirtothrips dorsalis H) and yellow mite(Polyphagotarsonemus latus banks) in chilli(Capsicum annuum L)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2008) Narsi Reddy, A; KAU; Sunny K, Oommen
    The present study aimed at evaluating a collection of chilli (Capsicum annuum L.) genotypes for yield and resistance to chilli thrips and yellow mite was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2006-2007. Fifty genotypes of chilli were evaluated for yield and yield components in a field experiment in randomized block design with three replications. Observations were recorded on 13 characters viz., days to 50% flowering, fruit bearing period, duration, primary branches per plant, secondary branches per plant, plant canopy width, number of fruits per plant, fruit length, fruit girth, fruit weight, number of seeds per fruit and yield per plant. Significant differences existed among genotypes for all the characters as revealed by the analysis of variance. The variety Ca 13 recorded the highest yield per plant (292.88g). Ca 15 was the lowest yielder (74.01g). Ca 10 recorded the highest number of fruits per plant (110.66). The variety Ca 20 recorded maximum plant canopy width (69.55cm). High phenotypic coefficient of variation with correspondingly high genotypic coefficient of variation was observed for number of fruits per plant, fruit yield per plant, secondary branches per plant and primary branches per plant. This indicated the existence of high degree of genetic variation and scope for improvement of these characters through selection. All the characters considered except days to 50% flowering recorded high estimates of heritability. High heritability coupled with high genetic advance was observed for number of fruits per plant, yield per plant and secondary branches per plant. There is immense scope for improvement of these characters through selection on account of their high magnitude of heritability and exceptionally high genetic advance. Fruit yield per plant showed high positive genotypic correlation with number of fruits per plant, duration, length of fruit bearing period, plant canopy width and number of secondary branches. The highest genotypic correlation of yield was with number of fruits per plant. Path analysis revealed that number of fruits per plant had the highest direct effect on yield. The indirect effect of the character via other characters was negligible. Plant canopy width also showed relatively high direct effect as well as positive indirect effect through number of fruits per plant and fruit weight. The study revealed that number of fruits per plant and plant canopy width are important in deciding yield and should be given due consideration in crop improvement programmes. Genetic diversity studies using Mahalanobis D2 statistic indicated considerable diversity among the 50 genotypes of chilli. The genotypes were grouped into eight clusters. Clustering pattern indicated that cluster I is having maximum number of genotypes. Maximum divergence was observed between clusters III and VI. The intracluster distance was the highest for cluster I. Selection indices of the 50 genotypes for yield were worked out using yield per plant and component characters viz., days to 50% flowering, fruit bearing period, duration, primary branches per plant, secondary branches per plant, plant canopy width, number of fruits per plant, fruit length, fruit girth, fruit weight and number of seeds per fruit. Maximum index value was obtained for Ca 13 followed by Ca 22 and Ca 18. Low index values were recorded for Ca 27 and Ca 15. Evaluation of the genotypes for resistance to chilli thrips and yellow mite was done to identify sources of resistance. Population count and leaf damage intensity were the criteria adopted for evaluation of resistance. The genotype that recorded the lowest number of thrips per leaf is Ca 13. Lowest leaf damage intensity was observed for Ca 43. Simultaneous consideration of population count and damage intensity suggested tolerance of Ca13 and Ca 35 to chilli thrips. These varieties are thus identified as promising sources of resistance to chilli thrips. Ca 35 was identified as the variety harbouring the lowest number of yellow mites. Leaf damage due to the mite was low for Ca 6. In view of the relatively low population count and leaf damage, Ca 6 and Ca 35 were identified as genotypes tolerant to yellow mite which can hopefully serve as sources of resistance to the pest. Ca 35 was the only genotype that showed resistance to both chilli thrips and yellow mite. The critical evaluation of the genotypes for tolerance to the pests also confirmed the tolerance of Ca 35 to both of these pests. The study identified Ca 13 as a genotype with high yield potential and tolerance to chilli thrips.
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    ThesisItemOpen Access
    Morphological and molecular analysis of coconut(cocos nucifera l.)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2008) Selvaraju, S; KAU; Jyalakshmi, V G
    The research project entitled Morphological and molecular analyses of coconut (Cocos nucifera L) was carried out in the Department of Plant Breeding and Genetics College of Agriculture, Vellayani during the year 2006-2008. The major objectives of this study include genetic analysis of six coconut cultivars with respect to fourteen morphological characters (vegetative and fruit characters),RAPD analysis of the coconut cultivars with 14 oligonucleotide primers and comparison of the genetic divergence of the six coconut cultivars with respect to morphological and molecular markers The study was conducted in six popular coconut cultivars, WCT, Komadan, Laccadive Ordinary, Natural Cross Dwarf, Chowghat Green Dwarf and Chowghat Orange Dwarf. Morphological data on fourteen biometrical traits in thirty palms belonging to six genotypes, with five palms for each genotype were subjected to statistical analysis. The analyses revealed that magnitude of variation represented by range; phenotypic coefficient of variation and genotypic coefficient of variation were moderately high for all the characters studied. High heritability coupled with high genetic advance was observed for weight of unhusked nut, weight of husked nut and number of nuts per palm per year. The coconut breeder therefore can make his selection on the basis of phenotypic expression of these characters in the individual palms. Correlation studies revealed that all the characters except plant height had significant positive correlation with yield. Path coefficient analysis revealed that eight out of thirteen characters showed positive direct effect on yield. Genetic divergence studies using Mahalanobis D2 analysis showed that the dwarf accessions are distinctly divergent from the rest of the accessions. The group constellations developed based on D2 totals showed that the local cultivar WCT and NCD were clustered together and the well preferred cultivar Komadan got clustered along with Laccadive Ordinary, the variety of Lakshadweep released in Kerala as “Chandrakalpa” for its superiority in performance. Maximum divergence was reported between Komadan and NCD .With regard to the characters chosen for the divergence analysis, it shows the importance of nut characters in assessing the genetic divergence in coconut. RAPD analysis using the 14 primers produced 107 amplicons within the molecular range of 2 kb to less than 0.5 kb. The primers chosen for the study reveal the advantage of GC-rich primers in bringing about amplification. Among the 14 primers studied, OPE-7 and OPB-05 produced maximum polymorphism of 43 percentage. The percentage of polymorphism produced by the 14 primers ranged from 10-43 with an average of 27 percentage. Among the fourteen primers studied, nine primers could produce unique products.The similarity analysis of the RAPD products show that the accessions are divergent with respect to RAPD markers. Similarity indices showed that the two accessions, COD and CGD are having 98 percentage similarity. Komadan had 89 percentage similarity with NCD and only 77 and 71 percentage similarity with WCT and Laccadive Ordinary. The dendrogram constructed also depicts the clustering of Komadan along with NCD and dwarfs. The least similarity was noted between Laccadive Ordinary and Chowghat Orange Dwarf. These divergent accessions can be used as parents for exploiting maximum heterosis. Divergent analysis with biometrical traits and RAPD markers slightly differed .In both analyses the dwarfs were clustered together. In the analysis with biometrical traits the divergence was 56 per cent and in the RAPD analysis it had 98 per cent similarity. Morphological markers clustered Komadan and Laccadive Ordinary together and West Coast Tall along with NCD. But in the RAPD analysis, West Coast Tall and Laccadive ordinary clustered together and Komadan clustered with dwarfs and NCD at 80 per cent similarity. Even though, Komadan is accepted as a superior palm its pedigree is controversial. A detailed molecular study can give a clear picture.
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    ThesisItemOpen Access
    Genetic variability in kacholam(kaempferia galanga L)under open and partially shaded conditions
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2008) Divya, Krishnan; KAU; Arya, K
    A research programme was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during the period 2007-08 with the object of assessing the genetic variability in kacholam genotypes for yield and yield attributing characters. Data on the investigations were recorded from two field experiments- one under open and other under partially shaded conditions. Twenty two genotypes including two released varieties (Kasthuri and Rajani) were evaluated for yield and related characters in field experiments in RBD with three replications under open and partially shaded conditions in coconut garden. Analysis of variance revealed significant difference among the genotypes for all the 37 characters studied. Genotypic and phenotypic coefficients of variation were highest for volatile oil, dry weight of roots, and fresh weight of leaves and fresh yield of rhizome per plant under both conditions. Under both conditions, characters such as fresh yield of rhizome, dry yield of rhizomes, fresh weight of leaves, dry weight of roots, length of secondary rhizomes and volatile oil showed high heritability coupled with high genetic advance. Rhizome yield showed significant positive correlation with fresh weight of leaves, number of suckers per plant and length of mother rhizome under both the conditions. Leaf area ratio was found to be negatively correlated with rhizome yield under both open and partially shaded conditions. Volatile oil, dry yield of rhizomes per plant, fresh yield of rhizome per plant, dry weight of roots, fresh weight of roots had highest heritability and genetic advance under two conditions viz., open and partially shaded condition. The characters such as plant spread, fresh weight of leaves, dry weight of leaves, number of suckers per plant, length of mother rhizome, number of secondary rhizomes, length of secondary rhizome, girth of secondary rhizome fresh yield of rhizomes and dry yield of rhizomes found to be positively and significantly correlated with oil yield under both conditions. Path analysis revealed that harvest index, dry weight of roots and dry weight of leaves were the primary yield contributing characters due to their high direct effect on rhizome yield. Mahalanobis D2 analysis clustered the twenty two genotypes into seven clusters. Cluster VII formed the largest cluster with 10 genotypes while clusters I, II and III had one genotype each. The genetic distance was maximum between clusters III and V while minimum divergence was between clusters II and VI. The intra cluster distance was highest for cluster IV. Selection index revealed that the genotypes Neyyattinkara attained maximum selection index value followed by Koothattukulam and minimum estimates were recorded by Alleppey and Kasaragod. The genotypes from Neyyattinkara, Koothattukulam, Madavur, Ponneyekkad, Kannur, Ponnukara and Kanyakumari district and were superior in terms of yield and quality parameters as pure crop and as an intercrop in coconut plantations. So these genotypes can be considered for further crop improvement programme.