PhD Thesis

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End date: 2009Subject: search.filters.subject.Plant Breeding and Genetics

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    Biochemical and molecular characterisation of njavara types of rice (Oryza sativa L.)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2005) Sanal Kumar, P; Elsy, C R
    Characterisation and evaluation of Njavara types of rice (Oryza sativa L.) was under taken in the Department of Plant Breeding and Genetics and Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara during 2001 - 2005 with the aim to characterise the Njavara genotypes based on morphological, biochemical and molecular characteristics, to evaluate its nutritional qualities and to analyse the stability of quantitative and nutritional traits. Morphological characterisation indicated that seven Njavara genotypes included in the present study exhibited similarity among themselves and with check variety for most of the qualitative characters. Some variations were observed with panicle type, panicle axis, apiculus colour, lemma and palea colour, seed coat colour and presence of awn. The Njavara genotypes viz., N1 and N2 (both Njavara types from Chittoor, Palakad) and N6 (Njavara type from Alwaye, Ernakulam) showed lemma and palea colour of black patches or furrows on straw background with black coloured apiculus, N3 and N4 (both Njavara types from Telllicherry, Kannur) showed lemma and palea colour of brown furrows on straw background with brown coloured apiculus, while N5 (Njavara type from Kottakkal, Malappuram) and N7 (Njavara type from Thrissur) showed a lemma and palea colour of gold furrows on straw background with an apiculus colour of straw. Njavara genotypes showed lesser days to maturity (67.9 to 79.1 days) with an average grain yield for Njavara genotypes ranging between 945.56 kg ha-1 and 2127.14 kg ha-1 was low compared to that of check varieties (2491.73 kg ha-1). Majority of the Njavara genotypes expressed high protein content than check varieties. The geotypes N2 and N6 were recommended to be included in weaning and invalid foods and diets during pregnancy and lactation. The genotypes N1, N2, N6 and N7 appeared to have better nutritive value based on the content of free amino acids. Most of the Njavara genotypes had intermediate amylose content ensuring consumer acceptance. Among the Njavara genotypes N3 has highest soluble carbohydrate content while others showed medium soluble carbohydrate content and are desirable as component of weaning and invalid food due to reduced gelatinization period and easy digestibility. Variability studies indicated that grain yield, straw yield and amylase activity provided a good genetic base for selection. The Njavara genotypes showed high heritability with high genetic gain for quantitative and nutritional characters. Correlation studies revealed that grain yield showed high positive correlation with high leaf width, days to 50 per cent heading, panicle length, days to maturity, straw yield, 1000 grain weight, grain width and amylose content. Nutritive factors like protein content and soluble carbohydrate content showed significant negative genotypic correlation with grain yield. Genotype x environment interaction showed that, N1 was stable for plant height panicle length, straw yield and protein content where as N2 was stable for traits like days to 50 per cent heading, culm diameter, days to maturity, grain yield, grain width and amylose content. N3 was stable for leaf length, days to 50 per cent heading and amylase activity where as N4 for leaf length and leaf width. The performance of N5 was stable for seedling height, plant height, panicle length, days to maturity, grain length and width, protein content, free amino acid content and amylose content while N6 was stable for ligule length, culm number, grain yield, 1000 grain weight, soluble carbohydrate content, free amino acid content and amylase activity. N7 had recorded stable performance for 1000 grain weight and soluble carbohydrate content. Biochemical characterisation indicated the possibility of utilising alcohol dehydrogenase polymorphism for identifying Njavara as a cultivar and also for identification of Njavara genotypes N1, N6 and N7. RAPD analysis of Njavara genotypes revealed good amplification with polymorphism for primers OPE 4, 6 and 16, OPP 7, 11, 12 and 19 and amplification with primers OPE 6, OPP 6 and OPP 11 exhibited unique bands for Njavara genotypes. The dendrogram drawn with two molecular markers viz., isozyme and RAPD revealed that the Njavara genotypes were grouped in one cluster whereas check varieties in another.
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    Heterosis breeding and in vitro mutagenesis in pineapple(ananas comosus[L] merr.)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2004) Kuriakose, K P; Pushkaran, K
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    Genetic analysis of yield and leaf curl virus resistance in chilli
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2004) Muthuswami, A; Abdul Khader, K M
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    Genetic analysis of yield and resistance to anthraconse in chilli(Capsicum annuum L)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2004) Ajith, P M; Manju, P
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    Genetic analysis of yield and quality attributes in fodder cowpea (Vigna unguiculata (L.) Walp)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Radhika, V S; Suma Bai, D I
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    Gene action and heterosis for yield, quality and fruit borer resistance in tomato (lycopersicon esculentum mill)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2002) Ebenezer Babu Rajan, R; Chandramony, D
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    Genetic analysis in ivygourd (Coccinia grandis (L) viogt)
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2003) Siby Varghese; Chandramony, D
    The present investigation entitled "Genetic Analysis in Ivygourd (Coccinia grandis (L) Voigt.) was conducted at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1999-2001. Objective of the study was to estimate the genetic basis of different characters, genetic divergence in the germplasm and to formulate a selection index for identifying superior types. The material for the experiment was 90 different local cultivars collected from different agroclimatic regions. The data for the investigation were collected from two field experiments, each laid out in Randornised Block Design with three replications. In Experiment I a collection of 50 genotypes of ivygourd was grouped into 11 clusters using Mahalanobis D2 statistic and based on eight morphological characters. Five genotypes Kuriyabandar local I, Kuriyabandar local Ill, Pilangatta local 11 & III and Kudlu local I, could not be grouped with others and so are kept as independent clusters. The cluster C IX was found to have maximum intercluster distance with seven of the eleven clusters formed. This was followed by C 11 which showed maximum divergence with four out of the eleven clusters. The results suggest that selection of parents from these divergent clusters will be effective in future hybridisation programme. The three superior crosses identified were Balthangadi local I x Pilangatta local 11, Bandargrarn local I x Pilangatta local 11 and Seetharnbeta local I x Pilangatta local II. Number of flowers per plant and number of leaves per plant were found to be the two characters that contributed maximum for the divergence of the genotypes. So both at phenotypic and cluster levels, these two characters can be considered as potential contributors of differentiation in Jvygourd. In Experiment II the data collected from 40 genotypes of ivygourd were subjected to analysis of variance and the genetic parameters like variability, heritability; genetic advance, correlation coefficients and path coefficients were estimated. Based on the above observation, a selection index was also formulated. Significant genotypic differences were observed among the 40 genotypes for all of the sixteen characters studied. High genetic variability was expressed by the characters fruit yield per plant, number of fruits per plant and number of flowers per plant. High heritability along with a good genetic advance was found for all the characters studied, except for number of days for first flower opening which exhibited high heritability and low genetic advance. These results indicate that the selection of plants which are phenotypically superior with respect to fifteen of the characters studied will certainly result in a significant improvement in the next generation. The genotypic correlation coefficients were higher than the corresponding phenotypic and environmental correlation coefficients revealing the fact that phenotypic expression of these correlations are reduced due to the influence of the environment. Yield per plant exhibited positive association with all the characters except number of days for flowering, which had significant negative correlation with yield. Number of fruits per plant and single fruit weight were the characters with high direct and indirect effects. Based on the above results, a selection index was formulated and local cultivars of Alappuzha, Kanjangad, Thirunelli, Mancheswararn and Nangikadapurarn were identified as the five top ranking genetically superior ivygourd genotypes. To sum up, the results of the present study indicates that being strictly a cross pollinated crop with possibility for vegetative propagation, methods of breeding which can. be successfully followed are individual plant selection, mass selection to improve varieties, pedigree method and heterosis breeding and vegetative propagation of the heterotic combinations. Considerable variability of the crop has been observed in Kamataka, Andhra Pradesh, Tarnil Nadu and northern parts of Kerala. There is considerable scope for survey, collection and maintenance of germplasm. The study highlights the feasibility of producing commercially viable indigenous selections and hybrids which are early, producing more number of bold and tender fruits with good storability and resistance to pest and diseases.
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    Characterisation of field established tissue culture derived black pepper (piper nigrum L.) plants using morphological, cytological and molecular markets
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2001) Sujatha, R; Mallika, V K
    Universally acclaimed as the ' King of Spices', black pepper (Piper nigrum L.) enjoys a unique position as a commercial crop of historical importance and assumes great economic importance to several nations of the world. Efforts to evolve high yielding types of black pepper through selection as well as hybridisation started as early as in 1953 (Nambiar et al., 1978) and by now, about ten improved varieties were evolved and released. In order to meet the insatiable demand from farmers for the planting materials of high yielding pepper varieties, mass multiplication protocol through micro-propagation has been standardised (Joseph et al., 1996). Babu (2000) tested the fidelity of TC plantlets of black pepper during the hardening stage using RAPD assay. A thorough evaluation and characterisation of these 'I'C plants in relation to their performance in the field is a prerequisite to establish their heritage and usefulness. In this background, the present study was taken up with the main objectives of establishing the genetic identity of TC derived black pepper plants in field; testing the intra-group, inter-clonal and inter- varietal polymorphism and obtaining a thorough and fool proof finger print of the TC plants using a combination of molecular marker techniques and conventional markers. Each of the experimental vines was characterised using morphological traits (biometric as well as qualitative) based on the descriptor formulated by NBPGR. The cytological studies ruled out any variation caused by a change in the chromosome number, which is possible in in vitro cultured plants. The somatic chromosome number was found uniform in all the vines with 2n = 52, which is characteristic of the species. The molecular markers provided a more specific identity for each of the experimental vines. The , zymogram based on peroxidase as well as RAPD banding pattern has given a very clear fingerprint characteristic of each vine. The biometric observations and visual assessment of the vines based on qualitative traits brought out the intra group (within conventional clones or within TC clones), inter- clonal (CC vs. TC clones) and inter varietal variation of the different characters. Among the 22 biometric observations, 17 were found homogenous within clonal groups and also within the TC groups irrespective of varieties. The remaining five traits were discussed with respect to each variety. Most of the qualitative observations also showed uniformity in. the clones as well as TC plants. The estimation of inter-clonal variablity proved the uniformity and better vigour of TC plants compared to the conventional clones. Another interesting observation was the great variablity in qualitative and quantitative traits between TC Subhakara and clonal Subhakara indicating a possible error in labelling. The molecular markers brought out the variablity in the different vines more specifically. In both isozyme and RAPD analysis, the clones under each variety were found to be monomorphic whereas certain variants could be detected within TC plants with respect to a few bands. The vines TC P2-7 and TC P1-1 were separated out as variants by both isozyme and RAPD markers. Other TC vines, which showed polymorphism with respect to either of these markers were Pl-I, PI-2, P2-10, P4-9, Su-9, Su-lO, P4-4 and P4-8. The assessment of inter clonal variability using molecular markers clearly pointed out the distinctly different traits of TC clones and conventional clones Subhakara. Morphological observations too supported this finding. Using RAPD, it was conclusively proved that the vines labelled as TC Su were in fact TC P 4. This confirmed the possibility of an error in labelling while the TC plantlets were transported from Vellanikkara to Panniyur. The inter-varietal polymorphism brought out by morphology and molecular markers was useful in discriminating the four black pepper varieties and to asses the genetic distance between them, which is an important criterion in the selection of parents for hybridisation. The results exposed the genetic proximity between PI and P2 and between P 4 and Suo The standardisations of various protocols for cytological and molecular marker analysis in black pepper as well as the relative efficiency of the different marker systems were also discussed. The RAPD technique was found most effective in assessing the genetic constitution of the individual vine.
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    Breeding for resistance to distortion mosaic virus in bittergourd (momordica charantia L.)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2002) Arunachalam, P; Radhakrishnan, V V
    The investigation on "Breeding for resistance to distortion mosaic virus in bittergourd (Momordica charantia L.)" was conducted at Department of Plant Breeding and Genetics, College of Horticulture, Kerala Agricultural University, Trichur, during 2000 to 2002. This study aims to identify the source(s) of resistance against bittergourd distortion mosaic virus (BDMV) and scope of incorporating these genes to high yielding varieties. This project also envisages the extent of genetic diversity, character association, combining ability, heterosis and gene action of quantitative traits in bittergourd. Out of 86 genotypes screened against BDMV, mne genotypes from Northern and Central parts of Kerala were identified as resistant viz., IC 68296, IC 68335, IC 68263B, IC 68275, IC 68250A, IC 85620, IC 68285, IC 68312 and IC 68272. Clustering pattern of genotypes did not follow geographical origin, but they were grouped based on BDMV reaction. The parent IC 68275 was identified as the best general combiner for BDMV resistance and fruit yield per plant. The other resistant parents viz., IC 68335 and IC 68263B were resulted in low fruit yield per plant can be used to diversify the source of resistance in hybridisation programme. Hybrids le 68250A x Preethi and VKV 134 x IC 68342B can be exploited commercially for high fruit yield in seasons of less incidence of distortion mosaic. The resistant hybrids IC 68263B x IC 68275 and IC 68275 x IC 68342B having moderately high yield can be utilized commercially during seasons or areas of high incidence of distortion mosaic. The resistant genes for this disease are freely transferable to high yielding varieties. Selection based on number of fruits, fruit weight and resistance to BDMV can be used for improving fruit yield. BDMV resistance is controlled by polygenes and their expressions are highly influenced by environment. The higher incidence of distortion mosaic was noticed during summer. Scope of exploitation of heterosis with resistance to distortion mosaic is suggested for further studies for confirmation and utilization.
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    Intra and interspecifif hybridization in dendrobium spp.
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2002) Lekha Rani, C; Mercy, S T
    An investigation on "Intra and interspecific hybridization in Dendrobium spp." was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, during 1998-2001 with the objective of developing new hybrids of Dendrobium with novel, commercial cutflower qualities for the export market. Fourteen genotypes of Dendrobium comprising of nine commercial varieties, three semi- commercial varieties and two species were selected as parents after initial evaluation. The parental genotypes differed significantly with respect to all the 21 characters studied. High heritability combined with high GCV and genetic advance were observed for length of inflorescence, length of scape, number of flowers per inflorescence and number of nodes per cane. Significant positive inter-correlation in all pair-wise combinations at genotypic and 'phenotypic levels was observed between seven characters viz., number of leaves per clump, height of cane, leaf area per cane, age at first flowering, cane to flower first, vase life and length of inflorescence. The 14 parental genotypes were crossed in all possible combinations (196) after preliminary studies on floral biology, anthesis and pollination. Six combinations could not be attempted as the flowering seasons of the genotypes concerned did not synchronise. A total of 1696 2 pollinations were done covenng 190 (88 crosses + 88 reciprocals + 14 selfs) combinations. Pollinated flowers/immature capsules from 106 combinations abscised at different stages. Green capsules were harvested from 84 combinations. Capsules from three combinations did not contain seeds and seeds from five combinations did not germinate on inoculation. Protocorms/developing seedlings from seven combinations aborted at various stages of in vitro development. Seedlings from 69 combinations were deflasked and transplanted. Two combinations failed to get acclimatized. Progeny from 67 (62 crosses and five selfs) combinations were established successfully in the green house. The levels of incompatibility reactions were grouped under nine heads ranging from flower abscission before the onset of any visible post pollination change to failure of hybrid seedlings to get acclimatized to the ex vitro green house conditions. A total of 123 combinations attempted succumbed to incompatibility at these different stages. Percentage capsule yield ranged from 8 to 33 in the various hybrid combinations. Percentage filled seeds ranged from 10.79 to 75.93 and percentage seed germination ranged from 8.00 to 70.73. The basal medium MS half strength was the best for early germination and rapid in vitro development as compared to MS quarter strength and MS, KC and VW full strengths. The effects of growth hormones, organic additives, sucrose and charcoal on in vitro seed germination and seedling growth were studied and the best concentrations were identified. Transplanting into the humidity chamber under conditions of high relative humidity (85-95%) and controlled irrigation resulted in 94 per cent survival after four weeks. The best among the potting media tried 3 was broken tiles + charcoal + Soilrite (2:2:1), favouring high survival and well balanced post transplantation seedling growth. The 67 hybrid combinations differed significantly with respect to all the eight vegetative characters studied at 1.5 to 2.0 years after transplanting. A partial diallel established with 18 cross combinations revealed the gca effect of P3 to be beneficial for number of shoots per clump, as it was positive and significant. Non additive gene action was responsible for character expression, as dominance variance was higher than additive variance. Sixteen hybrid combinations flowered, recording significant differences for all the 12 floral characters studied. Economic heterosis, relative heterosis and heterobeItiosis of the hybrid combinations were studied for all vegetative and floral characters recorded. Considerable vegetative vigour, earliness and increase in the size of flowers and inflorescences were registered by the hybrid combinations. From the 16 flowering combinations, about 40 promising hybrids were identified. Based on three important criteria viz., novelty, distinctiveness and uniformity of the floral characters, 25 out of these 40 new hybrids were selected. These hybrids show the potential for development into new, indigenous commerical varieties.