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ThesisItem Open Access Standardisation of selection criteria for cocoa hybrids(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Raji Varghese; KAU; Pushkaran, KInvestigation on standardisation of selection criteria for cocoa hybrids was conducted at Cadbury-KAU Co-operative cocoa Research Project (CC RP) Farm of Kerala Agricultural University, Vellanikkara during 1994-96. Twenty nine hybrids grown under Progeny Trial I and their 18 parents maintained in CYT-I were used for the study. The influence of seedling height and girth on yield was more pronounced in the case of seedlings one year after sowing than with those of 4 mas, 5 mas and 6 mas. The vegetative vigour measured by the height and diameter of trunk was found to be better correlated with precocity. The correlation coefficients of pod characters viz., length, width and weight of pods, number of beans, wet bean weight and pericarp thickness and seed characters viz., length, width, thickness and dryweight worked out between hybrids and female parents showed significant relationship in the case of pod length (r = 0.649) and number of beans (r = 0.606). But with mid parental value, the hybrids showed high correlation for the characters pod length, pod weight, number of beans, seed length, seed width and seed thickness (0.65, 0.45, 0.86, 0.70, 0.76 and 0.70 respectively). Heritability estimated by regressing offspring on female parent was high for the characters pod width, seed length and seed width (0,7, 0.64 and 0.78 respectively). Among the 29 hybrids studied, the hybrid H-4 of the cross GI 10.3 x GVI 54 was found to be promising in terms of both pod and wet bean yield. With the seedling characters of hybrids taken one year after sowing, a multiple regression equation for wet bean yield was fitted as: Y = 43 + 0.195 x1 + 3.70 X2 Where, x1 and X2 are height and girth of one year old seedlings respectively. This can be taken as a seedling selection criteria for cocoa hybrids.ThesisItem Open Access Genetic analysis of segregating generations of irradiated interspecific hybrids in okra (Abelmoschus spp.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1997) Sophia John; KAU; Manju, PA study* was. conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during l996-'97 to estimate the extent of variability generated in the f 2M? and F3M3 generations as a result of hybridisation and hybrid irradiation of the interspecific hybrids between A. s esculenins and A. manihot and also to isolate high yielding yellow vein mosaic disease resistant lines from among the segregating generations In the l-^M-, generation, the irradiated treatments were found to be late flowering and had more number of leaves per plant, flowers per plant and fruits per plant Irradiation was found to increase pollen sterility and was maximum in 10 kR However seed set was lower for the irradiated treatments. Average fruit weight and weight of fruits per plant was maximum in plants belonging to the treatment 20 kR. Fruit length and girth were found to increase with increasing radiation doses. Number of ridges per fruit, fruiting phase and plant duration were higher in the irradiated treatments when compared to 0 kR and was maximum in 40 kR Plant height was highest in the treatment 30 kR Irradiation was found to increase YVM disease incidence and fruit and shoot borer incidence and it was maximum in 30 kR among the irradiated treatments. However a few high yielding YVM disease resistant plants resembling the cultivated parent were also observed in 30 kR ■Genotypic coefficient of variation, heritability and genetic advance were high for number of branches per plant and number of seeds per fruit in all the irradiated treatments in F2M2. High heritability with high genetic advance were observed for leaf number, number of flowers per plant, Iruits • ' per plant and pollen sterility in 20 kR and 30 kR. Significant positive * . correlation of number of leaves per plant, flowers per plant and fruits per plant with weight of fruits per plant and also among themselves was observed in all the irradiated treatments in F2M0. Average fruit weight and fruit yield A* • 0 per plant were positively correlated in treatments 0 kR, 10 kR, 40 kR, P, and P2. % In F3M3 the irradiated treatments were found to be late flowering and had more number of leaves, branches, flowers and fruits per plant. Pollen sterility was lower for the irradiated treatments, when compared to the unirradiated treatment and was lowest in 30 kR. However the number of seeds per fruit was more in 30 kR compared to the other treatments excluding parental treatments. Irradiation was found to decrease average fruit weight but fruit yield per plant was more for the irradiated treatments due to the larger number of fruits and was maximum in 40 kR. Length of fruit increased with increasing radiation doses. Significant differences among the irradiated treatments were not observed with respect to number of ridges per fruit. Irradiation was found to increase the fruiting phase as well as plant duration. Plant height was maximum in 10 kR when compared to all the other treatments. Yellow vein mosaic disease incidence was high in the cultivated parent and the higher dose radiation treatments viz , 30 kR and 40 kR. From the present study *a few recombinants which resembled the cultivated parent, with high yield and YVM disease resistance could be isolated from 30 kR, which suggested that 30 kR could be ideal radiation dose for evolving high yielding YVM disease resistant lines in okra. Fruit and shoot borer incidence was highest in the cultivated parent and was also high in 30 kR. High to moderately high genotypic coefficient of variation was observed.lor number of branches per plant, leaves per plant, flowers per plant, fruits per plant, weight of fruits per plant and number of seeds per fruit in all irradiated treatments in F3M3. High heritability and genetic advance were observed lor number of fruits per plant, weight of fruits per plant, flowers per plant and pollen sterility in all the irradiated treatments. Number of leaves per plant, flowers per plant and fruits per plant were positively correlated with fruit yield per plant in all the treatments while average fruit weight had significant positive correlation with fruit yield per plant in 0 kR, P, and P2 in the F3M3 generation. As a future line of work, high yielding, YVM disease resistant plants assembling the cultivated parent which have been isolated from the treatment 30 kR will be further evaluated for a few more generations and if found superior and YVM disease resistant it will finally be developed into a YVM disease resistant variety.ThesisItem Open Access Genetic analysis of high yielding rice varieties of diverse origin(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Vanaja, T; KAU; Luckins, C BabuThe research project 'Genetic Analysis of High Yielding Rice Varieties of Diverse Origin' was carried out in the College of. Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during the period 1995-'98. The major objectives of the study were to understand the genetic architecture of high yielding rice varieties of diverse origin so as to evolve appropriate breeding methodology, to isolate promising lines having the new ideotype concepts from the segregating generations and to identify alternative source of cytoplasmic male sterile system suitable to warm humid climatic conditions experienced in Kerala. The study, about components of heritable variation revealed that the characters, number of panicles m-2 number of tertiary branches panicle-1, yield ha-1, spikelet sterility percentage and alkali spreading value exhibited high broad sense heritability coupled with high expected genetic advance and high genotypic coefficient of variation. High broad sense heritability and high expected genetic advance coupled with moderate genotypic coefficient of variation were manifested by the characters, namely, height of plant at harvest, second uppermost internodal length, length of flag leaf, ratio of vegetative phase to reproductive phase, number of spikelets panicle-1 number of grains panicle-1, LIB ratio of grain, milling percentage, amylose content, volume expansion ratio and water uptake. '1 Correlation studies revealed that the principal yield determining components in rice are harvest index, number of tertiary branches panicle-1 number of panicles m-2 number of grains panicle-1 number of spikelets panicle-1. ratio of vegetative phase to reproductive phase, 1000 grain weight, number of days to 50 per cent flowering, number of days to harvest and spikelet sterility percentage. While selecting genotypes for higher yield potential, emphasis should be given for comparatively long vegetative period, short period from panicle initiation to 50 per cent flowering and long ripening period. A selection model was formulated consisting of the characters, namely, yield ha-1 harvest index, number of days to harvest, number of tertiary branches panicle-1 ratio of vegetative phase to reproductive phase and number of grains panicle-1 Cluster analysis revealed that there was no parallelism between geographical distribution and genetic diversity. The 56 genotypes representing different eco-geographical regions were grouped into nine clusters based on genetic distances. Combining ability studies showed that both additive and non-additive gene effects were important, with predominance of non-additive gene action, for all the characters except for 1000 grain weight, second uppermost internodal length and height of plant at harvest. The varieties Vytilla3, Mahsuri, Mattatriveni and Karthika were identified as good general combiners. The varieties Mahsuri, Karthika, Vytilla 3, Mattatriveni and IR62030-18-2-2 showed pronounced cytoplasmic effect on yield and various yield contributing characters. The crosses Vytilla 3 x Mattatriveni, Mahsuri x Vytilla-3 an,d Mahsuri x Mattatriveni are recommended for recombination breeding. The crosses Vytilla 3 x IR36, Vytilla 3 x IR60133-184-3-2, PK3355-5-1-4 x Bhadra, Vytilla 3 x Mattatriveni, Karthika x Bhadra, PK3355-5-1-4 x Karthika and PK3355-5-1-4 x IR620'30-18-2-2 are recommended for heterosis breeding. The cytoplasm of Vytilla 3 (an improved saline tolerant variety of Kerala) was identified as an alternative source for cytoplasmic male sterility in rice, suitable to warm humid tropical climate, experienced in Kerala. The varieties IR36 (international check) and Hraswa (extra short duration high yielding variety of Kerala) are the proposed maintainer lines. Mattatriveni is the proposed restorer line for the proposed IR36 'A’ line and Hraswa 'A’ line. The generation mean analysis using six parameter model revealed that both additive and non-additive gene effects played an important role in the inheritance of yield and important yield components, with predominance of dominance, additive x additive and dominance x dominance type of gene effects. Results of inbreeding depression indicated absence of reduction in vigour in the F2 generations for yield and all other yield attributes. Investigation on pattern of inheritance of kernel colour revealed that kernel colour in rice is a complex qualitative character. Each red and white colour may be separately controlled by two or more sets of genes having both inhibitory and duplicate type of gene interactions with predominance of inhibitory type gene interaction. From 22F2 generations, seven early stabilized promising lines and 26 promising segregants were selected. Two early stabilized lines were found to possess most of the ideotype features proposed by IRRI with preferable cooking quality characters. Their further evaluation and multiplication are being carried out at the Agricultural Research Station, Mannuthy, Kerala Agricultural University. By hybridization, it was possible to successfully transfer the non sticky nature and red kernel colour of Mattatriveni to a high yielding Taiwan variety whose kernel is white and sticky on cooking. The gene action studies revealed that there is ample scope for yield improvement in rice both through pedigree breeding and heterosis breeding. As yield and yield components were found to be under the control of all the three types of gene actions namely, additive, dominance and epistasis, intercrossing of early segregating generations derived from multiple crosses seems to be the best suited method of breeding for yield improvement in rice. Future line of studies suggested 1. Conversion of the already obtained cytoplasmic male sterile F1 crosses to fully sterile CMS lines by repeated back crossing with the respective recurrent parents. 2. Screening from the segregating populations of these cytoplasmic male sterile crosses for 100 per cent cytoplasmic male sterile lines. 3. Confirmation of the restoring ability of the proposed Mattatriveni 'R' line and identification of other restorers. 4. Incorporation of the sterile cytoplasm of Vytilla 3 into other elite genotypes other than IR36 and Hraswa. 5. Screening for cytoplasmic male sterile system in other saline tolerant lines. 6. Screening of promising segregants selected, for high yield and quality with multiple resistance to pest and diseases, for developing varieties suited to various climatic and soil conditions of Kerala.ThesisItem Open Access Genetic analysis of seed dormancy and productivity in groundnut (Arachis hypogaea L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1997) Tessy Joseph; KAU; Namboodiri, K M NInvestigations on genetic analysis of seed dormancy and productivity in groundnut (Arachis hypogaea L.) were carried out in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara from 1992-95. The objective of the study was to find out the gene effects of biometric traits and seed dormancy in groundnut, so as to suggest appropriate breeding methodology and parental combinations to evolve domant, high yielding and early manuring varieties. The findings of the study are briefed below. Evaluation of 28 genotypes (14 domant and 14 non domant) for two seasons revealed that wide range of variability existed among them. Donors for specific traits were identified . The genotypes were also genetically diverse and could be grouped into four clusters. The line x tester analysis with three lines and five testers revealed that additive gene effects governed most of the characters except pod yield and number of mature pods , for which , non addictive gene effects were important. To harness both the types of gene effects pedigree method followed by selection in advanced generations will be fruitful.ThesisItem Open Access Estimation of combining ability and heterosis in snakegourd(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1999) Radhika V S; KAU; Abdul Khader, K MA diallel analysis in snakegourd iTrichosanthes anguina. L.) was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during the period 1997-1999. The research work was taken up to assess the general and specific combining abilities, nature of gene action and also to estimate the heterosis for various characters. The six parents involved were selected from a previous D2 analysis conducted in the Department and were the most divergent ones. They are PI (Nedumangad local), P2 (Thrikkannapuram local), P3 (Kanhangad local - 3), P4 (Vlathankara local), Ps (Kaumudi) and P6 (Idukki local). The observations were recorded on yield and yield attributing characters. Significant differences were detected among the mean performance of the genotypes, for all the characters studied. The combining ability analysis revealed that the parent P, (Kaumudi) was the best general combiner for most of the yield and and yield contributing traits. The hybrids PI x Ps, P2 X P, and P2 x P6 were superior specific combiners in yield characters like mean weight of fruit, number of fruits per plant and fruit yield per plant respectively. The crosses involving P, and P6 were found to be good specific combiners for yield and yield contributing characters. The variance due to general and specific combining ability was significant in almost all the characters studied indicating the significance of both additive and non additive gene action in the characters. The sea variance was found to be more than gca variance in most of the characters studied indicating the predominance of non additive gene action. The ratio of additive to dominance variance was less than one in most of the characters again indicating the predominant influence of non additive gene action which strongly substantiated the validity of the heterosis breeding method in improving the crop. Manifestation of heterosis was seen for all the characters studied. Among the hybrids, P2 x Ps had the maximum standard heterosis for yield and yield related characters. The crosses PI x Ps, P, X P(, and P3 x P, also exhibited significant standard heterosis for these characters. In general the hybrids involving the parent Ps was found to be more heterotic.ThesisItem Open Access Intervarietal hybridization in Anthurium andreanum Linden(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1999) Renu, R S; KAU; Mercy, S TThe present study on evaluation of morphological characters and compatibility reactions among ten selected Anthurium andreanum varieties, was undertaken to analyse the scope for genetic improvement in this crop. The analysis of variance revealed significant variation among the ten varieties for the twelve quantitative characters studied. This reveals the high genetic potential for the improvement of this crop. Variability studies indicated that high phenotypic and genotypic coefficients of variation for the characters plant height, position of candle, days to initiation of female phase, number of days in female phase and spathe size. The characters with heritability coupled with high genetic advance values were plant height, spathe size, spathe-candle ratio, position of candle, number of flowers per candle and days to initiation of female phase, indicating additive gene action. Plant height was found to be positively correlated with number of leaves or spadices per year. Spathe size and candle length were positively correlated. Candle length had high positive genotypic correlation with position of candle and number of flowers per candle. Pollen fertility ranged from 42 per cent in Liver Red to 13.7 per cent in Mauritius Orange. Study of pollen emergence pattern revealed significant differences among the varieties. Pollen emergence was completely absent in Pompon Red, Nitta Orange and Midori Green during the period of study. Pollen production was high in the cooler months of October to December and was suppressed during the hot months of March to June. Cross compatibility analysis based on the results of intervarietal hybridisation was done using the three parameters; i.e., percentage of candles bearing fruits, percentage fruit set and percentage seed •germination. The percentage of fruit bearing candles were highest for Nitta Orange (51.93 per cent) and lowest for Mauritius Orange (9.51 per cent). The only two selfings that produced fruiting candles were LR x LR and DT x DT. The number of fruits per candle ranged from five to 183. The variety Pompon Red had the highest average number of fruits per candle and it was lowest for Lady Jane. The percentage of fruit set was below 50 per cent for all the crosses except PR x LR. The crosses involving Pompon Red as female parent had the highest percentage of fruit set. The number of days taken for seed germination varied from three to twelve days. The seed germination was highest (87.5 per cent) for the cross DT x MW. Among the varieties it ranged from 69 per cent in Tropical Red to 2.3 per cent in Midori Green. Seedling survival at four to six month stage was highest for the crosses of Mauritius Orange and the lowest for those of Midori Green. The cross TR x MW showed 100 per cent seedling survival. Scoring of the compatibility reactions based on fruiting candles, fruit set and seed germination, on a scale ranging from O to 9, showed the highest compatibility' score of nine for PR x LR and CR x MW crosses. The best female parents were identified as Nitta Orange, Liver Red and Pompon Red based on the overall performance. The analysis of the performance of varieties as pollen parents on the same basis showed that Ceylon Red, Merengue White and Liver Red are the best pollen parents. These observations showed that the performance of a variety as female parent was different from its performance as male parent. Only the variety Ceylon Red and Liver Red performed well both as female and male parent.ThesisItem Open Access Genetic analysis of segregating generation of inter varietal crosses in greengram(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1999) Ebenezer Babu Rajan, R; KAU; Wilson, DThe research programme was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, VelIayani during rabi season 1998-99, with the objective of identifying superior progenies in the F2 generation for yielding ability and nitrogen fixation 'potential. Seven parents and F 2 progenies of their 21 crosses of greengram were evaluated, adopting a randemised block design with three replications. The data collected for thirteen quantitative characters were analysed statistically. The genetic parameters, correlation and path coefficients were studied and a selection index was formulated to identify superior genotypes. The treatments showed significant difference for all the characters. High genotypic coefficient of variation was observed for weight of nodules in the root at 50 per cent flowering, dry weight of plants at maturity, nitrogen content of plants at maturity and grain yield. High heritability coupled with high genetic advance was observed for weight of nodules in the root at 50 per cent flowering followed by dry weight of plants at maturity, grain yield, number of pods, number of cIuslters per plant, harvest index, hundred grain weight, number of secondary roots at maturity, plant height and shoot/root ratio indicating additive gene action and reliability of these characters during selection programme for crop improvement. High positive genotypic correlation for number of pods per plant followed by number of clusters per plant, harvest index, plant height, hundred grain weight and number of seeds per pod indicated selection based on one or more of the above components may result in the improvement of grain yield. The path coefficient analysis revealed high positive direct effects of number of pods on grain yield. In addition hundred grain weight and number of seeds. per pod also showed positive direct contribution to grain yield. A selection index was constructed based on grain yield per plant and eight yield contributing characters identified through correlation and path analysis. Based on the selection index one of the parental varieties CoGG-902 ranked first followed by Pusa-9333 x NDM-88-14, Pusa-9333, KM-1285 x CoGG-902 and IlPRM-3 x LG-444 were identified as superior for yielding ability and nitrogen fixing potential.ThesisItem Open Access Induction and evaluation of genetic variability in chethikoduveli(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1999) Arya, K; KAU; Gopimony, RThe present study "Induction and evaluation of genetic variability in Chethikoduveli (Plumbago rosea L.) was undertaken in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1995-1998. The study was undertaken through the conduct of two experiments. (i) Germplasm collection and evaluation (ii) induction of variability. Two noded semi-hardwood cuttings of seven ecotypes of Plumbago rosea and one related species, Plumbago zeylanica were used for the first experiment. The ecotype of P. rosea from College of Horticulture, Vellanikkara was used for the second experiment. The cuttings were treated with six doses of gamma rays (0.25, 0.50, 0.75, 1.00, 1.25 and 1.50 kR) and M I V I generation was evaluated. Pollen germination was not noticed in P. rosea whereas the pollen grams of P. zeylanica germinated. The germination of seeds was more quickly in scarified seeds of P. zeylanica than seeds with intact seed coat. All the pollination techniques failed to give any positive result on seed set in P. rosea. Normal pairing of chromosomes were observed in meiotic cells of both the species. All characters studied had significantly high genotypic correlation with yield. High estimates of heritability (broad sense) was observed for all characters studied. High estimates of heritability coupled with high genetic advance was observed for plant height and root length which indicate that direct selection for improvement of these traits will be effective. Path coefficient analysis showed that dry root yield had maximum direct effect on plumbagin content of roots and plant height had maximum direct effect on fresh and dry root yield. The index score for selection was highest for P zeylanica followed by the ecotype of P rosea from Kottayam. EDso of gamma rays for the stem cuttings of P rosea was 1.685 kR. The sprouting percentage of cuttings was significantly decreased with increased doses of mutagen. Progressive delay in sprouting was noticed as the level of dose increased. The percentage lethality was higher in mutagen treated population than in the control. The optimum dose for inducing maximum yield and yield attributing characters ranged between 0.70 kR and 0.85 kR of gamma rays. High yielding mutants were observed in plants treated with 1.0 kR of gamma rays. The highest values for yield and yield attributing characters were obtained for 0.75 and 1.00 kR gamma rays. Gamma rays at 1.0 kR was most effective in inducing variability for root yield.ThesisItem Open Access Combining ability for biological nitrogen fixation traits and yield components in blackgram (Vigna mungo (L.) Hepper)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1998) Beena Thomas; KAU; Sreekumar, S GThe research programme was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1995-96. The objective was to assess the general and specific combining abilities and gene action involved in the inheritance of biological nitrogen fixation traits and yield components in blackgram, as a preliminary step for developing high yielding varieties with good biological nitrogen fixation capacity. The five lines, three testers and their 15 combinations were evaluated in a replicated field experiment and data on twelve characters were collected and subjected to line x tester analysis. The best general combiners for important biological nitrogen fixation traits were COBG305 and Pant U19 among lines and T9 among testers. The hybrid combination Pant U19 x T9 was the best specific combiner for these characters. In the case of number of pods and grain yield per plant, among. lines WBG-13 and among testers T9 were the best general combiners. The hybrids, LBG 17 x VBN 1 and WBG 13 x AKU4 were the best specific combinations for these traits. Considering the mean performance, sea effect and standard heterosis percentage Pant U 19 x T9 was identified as the best hybrid combination for nodule weight and nitrogen content at 50 per cent flowering. Regarding yield, the best hybrid was WBG 13 x AKU4. These superior combinations can be utilized further for developing improved blackgram varieties.
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