1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Development of fusarium wilt resistant breeding lines of yardlong bean(Vigna unguiculata subsp.sesquipedalis (L.) Verdcourt) variety githika(Department of Genetics and Plant Breeding, College of Agriculture , Vellayani, 2025-02-17) Sreeja, R.; Nivedhitha, M SThe present study entitled “Development of fusarium wilt resistant breeding lines from yard long bean (Vigna unguiculata subsp.sesquipedalis (L.)Verdcourt) variety Githika was conducted in the Department of Genetics and Plant Breeding, College of Agriculture, Vellayani during 2023-24, with an objective of evaluation of back cross progenies from Githika for fusarium wilt resistance and yield related traits. The research program consisted of 4 main experiments. First experiment involved evaluation of 35 BC2F1 lines resistant to fusarium wilt developed in the concluded Ph.D project Shahiba, (2023) for yield and related traits of the recurrent parent Githika and 10 lines with maximum morphological similarity with Githika was selfed to produce BC2F2 seeds.This experiment was done in a completely randomized design (CRD) with 2 replications. Evaluation of biometric as well as quality parameters in the 35 BC2F1 lines showed significant variations. High heritability along with high genetic advance was observed for all the characters studied except days to 50% flowering. In experiment 2, a total of 74 BC2F2 seedlings from the 10 selected BC2F1 lines were artificially screened for fusarium wilt resistance during the seedling stage. The pathogen associated with fusarium wilt in yard long bean was subcultured from the already isolated and cultured fungal culture plates developed in the concluded Ph.D project Shahiba, (2023). The isolate obtained were mass multiplied in the sand:maize (9:1) medium at 28°C. Soil inoculation method with 10% inoculum of the pathogen multiplied in the sand:maize (9:1) medium was used to produce disease symptoms on artificial inoculation. The scoring for disease incidence was done using the 0-4 scale reported by Senthilkumar (2003). Out of this 74 BC2F2 lines screened, seventy-one were resistant, two were moderately resistant and one was highly susceptible. In experiment 3, the resistant BC2F2 segregants which were in close proximity to the recurrent parent and with a disease score of ‘0’ were backcrossed to produce BC3F1 lines. Out of 217 pollinations, 22 set into pods and about 248 seed set was observed and pod set percentage was found to be 10.13%. In experiment 4, the 11 BC3F1 lines having maximum morphological similarity with the recurrent parent was morphologically evaluated for the 7 biometric characters. This experiment was done in a completely randomized design (CRD) with 3 replications. Analysis of variance revealed a significant variation among the lines for 7 biometric characters. High phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) was observed for pod yield per plant and moderate PCV and GCV were observed for number of pods per plant, pod weight and number of seeds per pod. High heritability along with high genetic advance was observed in pod weight and pod yield per plant, thereby indicating that these traits are predominant in additive gene action. Moderate heritability along with high Genetic advance was recorded for traits such as number of pods per plant and number of seeds per pod, while high heritability combined with moderate Genetic advance was observed for the trait pod length. The pod yield per plant was positively correlated with number of primary branches per plant, number of pods per plant, pod weight, pod length, number of seeds per pod and was negatively correlated with days to 50% flowering. Path analysis of biometric characters revealed that the pod weight had the highest direct positive effect on pod yield per plant, followed by number of pods per plant. A high positive indirect effect on pod yield per plant was shown by pod weight through number of seeds per pod. From the study, 11 resistant BC3F1 lines BG3 1-4-1, BG3 6-3-4, BG313-6-2, BG3 50-2-3, BG350-2-5, BG3 50-2-6, BG3123-1-1, BG3 123-5-2, BG3 123-5-7, BG3123-5-8 and BG3130-2-4 which were in close proximity to the recurrent parent, Githika was obtained and could be carried forward for further evaluation. The BC3F2 seeds of 11 lines found resistant to fusarium wilt could be used as breeding lines for developing varieties resistant to fusarium wilt along with the traits of Githika through a backcross program.Item Induction and regulation of flowering in rice bean [Vigna umbellata (Thunb.)](Department of Genetics and Plant Breeding, College of Agriculture,Vellayani, 2025-01-23) Aiswarya Chandrahasan.The present study entitled ―Induction and regulation of flowering in rice bean [Vigna umbellata (Thunb.)]‖ was carried out in the Department of Genetics and Plant Breeding, College of Agriculture, Vellayani during 2022-24. This study aimed to regulate flowering in rice bean through hormonal application and analyze the upregulation of flowering-related genes. The research programme comprised of two experiments. The first experiment was hormonal application to regulate flowering and second experiment included flowering gene expression analysis. The experiment was laid out in randomized block design with ten treatments and three replications. The plot size of 3m2 was followed in the field experiment. The experimental materials for the present study were fodder rice bean varietes Surabhi from KAU and Bidhan-2 from BCKV, Kalyani. The treatments comprised of control, seed inoculation with Piriformospora indica and different doses of foliar sprays (Salicylic acid at 100 and 150 ppm, Gibberellic acid at 200 and 300 ppm, Paclobutrazol at 10 and 20 ppm and KNO3 at 1 and 1.5%) at 30 days after sowing (DAS). The observations on quantitative characters and qualitative characters showed significant differences among treatments, except for field emergence in variety Surabhi. Early flowering was observed in Surabhi treated with SA at 100 ppm (65.36 DAS), followed by GA₃ at 300 ppm (67.72 DAS), SA at 150 ppm (67.81 DAS), and Paclobutrazol at 10 ppm (69.87 DAS), while control flowered last (80.96 DAS). No flowering was observed in Bidhan-2. Seed inoculation with P.indica improved fodder qualities like LAI, number of branches, plant height, number of pods per plant and green fodder yield per plot in rice bean variety Surabhi. The highest seed yield was also recorded in plants treated with P.indica (81.88 g) and lowest in plants treated with Salicylic acid at 150 ppm (47.88 g). A significant positive correlation was exhibited by days to first flowering with days to 50% flowering (0.992) and days to maturity (0.979), whereas number of branches 95 (-0.537) and number of seeds per plant (-0.41) exhibited significant negative correlation. A significant positive correlation was recorded by green fodder yield per plot with LAI (0.997), dry fodder yield per plot (0.962), plant height (0.949), number of branches (0.746) and field emergence (0.335). Path analysis revealed that days to maturity exhibited highest direct effect on days to first flowering (0.912). Rest of the characters showed a negligible direct effect on days to first flowering. The highest positive indirect effect on days to first flowering was observed by days to maturity through days to 50% flowering (0.905). Principal component analysis showed 85.88% contribution of first 4 PC groups towards the total variance and the squared cosine diagram showed that days to first flowering exhibited maximum value in PC1 which accounted for 34.22% of total variance. The RNA isolated from the flower buds of control and the treatment of which showed earliest flowering (SA at 100 ppm) were converted to complementary DNA (cDNA). The expression levels of genes ELF3 and FT in the selected treatments were studied using the quantitative real time PCR. The relative expression of control and treated plants demonstrated the varying degree of flowering gene expression. The relative expression profile using ELF3 gene showed 1.42 fold increase in treated plants (SA at 100 ppm) as compared to control indicating the upregulation of flowering gene ELF3 in treated plants. In conclusion, foliar application of Salicylic acid at 100 ppm was found to be the best treatment in rice bean variety Surabhi for inducing early flowering. Treated plants flowered 15 days before control. Plants treated with GA3 at 300 ppm, Paclobutrazol at 10 ppm and KNO3 at 1% flowered 13, 11 and 3 days respectively before control. Seed inoculation with P.indica resulted in flowering 7.5 days before control in Surabhi. Seed inoculation with P.indica resulted in improvement of fodder qualities like LAI, number of branches, plant height, number of pods per plant and green fodder yield per plot in both the rice bean varieties (Surabhi and Bidhan-2). Seed yield was also highest (Surabhi) in plants treated with P.indica. No flowering was observed in variety Bidhan-2. The 96 differential expression analysis using RT-qPCR revealed an upregulation of ELF3 genes in treated plants which correlated with an accelerated flowering response. Future studies could explore the different range of hormonal concentrations to determine the optimal dose for inducing early flowering in rice bean, as well as any potential toxic effects at higher doses.Item Induction and regulation of flowering in rice bean [Vigna umbellata (Thunb.)](Department of Genetics and Plant Breeding, College of Agriculture,Vellayani, 2025-01-23) Aiswarya Chandrahasan.The present study entitled ―Induction and regulation of flowering in rice bean [Vigna umbellata (Thunb.)]‖ was carried out in the Department of Genetics and Plant Breeding, College of Agriculture, Vellayani during 2022-24. This study aimed to regulate flowering in rice bean through hormonal application and analyze the upregulation of flowering-related genes. The research programme comprised of two experiments. The first experiment was hormonal application to regulate flowering and second experiment included flowering gene expression analysis. The experiment was laid out in randomized block design with ten treatments and three replications. The plot size of 3m2 was followed in the field experiment. The experimental materials for the present study were fodder rice bean varietes Surabhi from KAU and Bidhan-2 from BCKV, Kalyani. The treatments comprised of control, seed inoculation with Piriformospora indica and different doses of foliar sprays (Salicylic acid at 100 and 150 ppm, Gibberellic acid at 200 and 300 ppm, Paclobutrazol at 10 and 20 ppm and KNO3 at 1 and 1.5%) at 30 days after sowing (DAS). The observations on quantitative characters and qualitative characters showed significant differences among treatments, except for field emergence in variety Surabhi. Early flowering was observed in Surabhi treated with SA at 100 ppm (65.36 DAS), followed by GA₃ at 300 ppm (67.72 DAS), SA at 150 ppm (67.81 DAS), and Paclobutrazol at 10 ppm (69.87 DAS), while control flowered last (80.96 DAS). No flowering was observed in Bidhan-2. Seed inoculation with P.indica improved fodder qualities like LAI, number of branches, plant height, number of pods per plant and green fodder yield per plot in rice bean variety Surabhi. The highest seed yield was also recorded in plants treated with P.indica (81.88 g) and lowest in plants treated with Salicylic acid at 150 ppm (47.88 g). A significant positive correlation was exhibited by days to first flowering with days to 50% flowering (0.992) and days to maturity (0.979), whereas number of branches 95 (-0.537) and number of seeds per plant (-0.41) exhibited significant negative correlation. A significant positive correlation was recorded by green fodder yield per plot with LAI (0.997), dry fodder yield per plot (0.962), plant height (0.949), number of branches (0.746) and field emergence (0.335). Path analysis revealed that days to maturity exhibited highest direct effect on days to first flowering (0.912). Rest of the characters showed a negligible direct effect on days to first flowering. The highest positive indirect effect on days to first flowering was observed by days to maturity through days to 50% flowering (0.905). Principal component analysis showed 85.88% contribution of first 4 PC groups towards the total variance and the squared cosine diagram showed that days to first flowering exhibited maximum value in PC1 which accounted for 34.22% of total variance. The RNA isolated from the flower buds of control and the treatment of which showed earliest flowering (SA at 100 ppm) were converted to complementary DNA (cDNA). The expression levels of genes ELF3 and FT in the selected treatments were studied using the quantitative real time PCR. The relative expression of control and treated plants demonstrated the varying degree of flowering gene expression. The relative expression profile using ELF3 gene showed 1.42 fold increase in treated plants (SA at 100 ppm) as compared to control indicating the upregulation of flowering gene ELF3 in treated plants. In conclusion, foliar application of Salicylic acid at 100 ppm was found to be the best treatment in rice bean variety Surabhi for inducing early flowering. Treated plants flowered 15 days before control. Plants treated with GA3 at 300 ppm, Paclobutrazol at 10 ppm and KNO3 at 1% flowered 13, 11 and 3 days respectively before control. Seed inoculation with P.indica resulted in flowering 7.5 days before control in Surabhi. Seed inoculation with P.indica resulted in improvement of fodder qualities like LAI, number of branches, plant height, number of pods per plant and green fodder yield per plot in both the rice bean varieties (Surabhi and Bidhan-2). Seed yield was also highest (Surabhi) in plants treated with P.indica. No flowering was observed in variety Bidhan-2. The 96 differential expression analysis using RT-qPCR revealed an upregulation of ELF3 genes in treated plants which correlated with an accelerated flowering response. Future studies could explore the different range of hormonal concentrations to determine the optimal dose for inducing early flowering in rice bean, as well as any potential toxic effects at higher doses.Item Molecular characterization of brinjal (Solanum melongena L.) genotypes and their performance assessment in summer(Department of Genetics and Plant Breeding, College of Agriculture, Padanakkad, 2023-05-31) Chakravaram, Alekhya; Namboodiri Raji VasudevanItem Genetic improvement in Dendrobium orchids through hybridization and molecular characterization(Department of Plant Breeding and Genetics, College of Agriculture,Vellayani, 2023) Amrutha Unni, M.; Beena ThomasThe present study entitled “Genetic improvement in Dendrobium orchids through hybridization and molecular characterization’ was carried out at Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, during 2018-2022, with an objective to assess the genetic variability in commercially important Dendrobium orchids to develop superior hybrids and confirming hybridity through molecular markers. Twenty Dendrobium orchid genotypes with desirable traits and widespread market acceptance were collected, planted in the greenhouse and assessed for variability, heritability, genetic advance and correlation. Analysis of variance showed significant differences among the genotypes for all the characters studied. For the majority of the analysed traits, the mean performance has a broad range of variation among the parents. D. Thong Dang Yellow showed higher mean performance for internode length and plant height. Of the 20 genotypes, 15 flowered, while five genotypes failed to flower due to environmental factors and less adaptations. So the floral characters of 15 genotypes were studied. D. White represented desirable mean values for inflorescence diameter and inflorescence number per plant, D. Rabit Gold showed higher mean performance for pollen fertility and days to first flower opening from inflorescence, D. Gift by God Candy showed higher mean value for flower width in front view and days to last flower opening from first flower and D. Burana Pearl x D. Burana White showed higher peduncle length and vase life. For the vegetative characters, the thickness of leaf exhibited the highest GCV (66.16%) and PCV (69.54 %). High heritability coupled with high genetic advance was recorded for plant height, number of leaves per shoot, number of aerial roots, length of aerial roots, thickness of the shoot, internodal length, length of the leaf and leaf area which indicated that these traits were controlled by additive gene action. For the floral characters the maximum PCV and GCV were found in flower width in front view. All the floral characters showed high heritability along with high genetic advance, demonstrating that these traits were controlled by additive gene action. Plant height showed the strongest positive correlation with the number of aerial roots among the vegetative characters. Significant highly positive correlation was found between the number of inflorescences per plant and the inflorescence axis diameter. Days to first flower opening from inflorescence emergence recorded significant positive correlation with inflorescence axis diameter. Out of the 15 genotypes studied, three genotypes exhibited seasonal flowering nature and all others were free flowering. Inflorescence axis was found to be pendulous in D. Yaya and the rest of the genotypes produced erect or arching type of inflorescence axis. Flower fragrance were present in D. Red Fairy, D. Thong Dang Yellow, D. Popeyes and D. Gift by God Candy. Shape of flower was found as full and round, flat and surfaced with broad sepals and petals. In the study, thirty ISSR primers were used to examine the genetic diversity of 20 orchid hybrid genotypes used in this study. A total of 102 bands were produced, out of which 57 bands found were polymorphic and 45 bands were monomorphic in nature. Polymorphic information content value of the primer ranged between 0- 0.49. Dendrogram was generated using NTSYS-pc 2.02e software and the twenty genotypes were grouped into five clusters. Divergent lines identified were D. Pink bfc, D. Pearl Red Lip and D. King Dragon. The best ten parental genotypes were crossed based on flower synchronization and availability of pollen. A total of 20 cross combinations were attempted. Incompatibility reactions were noticed at different stages ranging from flower abscission before the onset of any visible post pollination change to instances where seeds germinated but aborted in culture. Mature green capsules were harvested from 12 combinations at 70 to 90 per cent maturity. The 12 combinations were inoculated in vitro, but four of them did not produce any seeds in the capsule and one did not germinate. All seven in vitro cultured combinations were successfully germinated and were sub cultured three to four times. The basal media used for the in vitro propagation was half MS. The in vitro growth of the hybrid Dendrobium was improved by supplementing with BA (1 mg/l), IAA (0.1 mg/1) and charcoal (4g/l) was found to be effective. Deflasked seedlings with three or more leaves and three or more roots were then transferred in half MS media. There was significant variance among the number of days required for germination, protocorm development, emergence of first leaf, the first shoot, the first root primordia and deflasking. At deflasking, there were noticeable variations in seedling morphology among the seven hybrid combinations. The present research work identified 10 commercially popular hybrid genotypes that excelled in floral features and diversity attributes. The hybrid plantlets developed through hybridization are to be hardened and maintained in net house for evaluation of morphological and floral traits. These can be utilized in further crop improvement programmes in Dendrobium.Item Genetics of shattering resistance in rice (Oryza sativa L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2020) Akhil, K P; Biju, SItem Genetic divergence and selection parameters in basmati rice(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1999) Sreejaya, K C; Radhakrishnan, V VThe research project 'Genetic divergence and selection parameters in Basmati rice was carried out in the College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during the period 1995-'97. The major objectives of the study were to study the genetic divergence among advanced breeding lines of Basmati rice evolved at various rice research centres in India and to select high yielding quality Basmati rice genotypes adopted to Kerala ecosystem. The study, about components of heritable variation revealed that the range of variation is high for height of plant at harvest, total number of tillers, numbers of panicle bearing tillers, number of panicles/ m2 , number of spikelets/panicle, pubescence, awnness, num- ber of grains/panicle, aroma, overall acceptability, amylose content, kernel elongation after cooking, elongation ratio and yield. Heritability studies revealed that pH of raw grain, LIB ratio, kernel breadth and taste showed the maximum broad sense heritability among the qualitative characters; number of days to panicle initiation also had high heritability among the quantitative characters. Cluster analysis revealed that there was no parallelism between geographical distribu- tion and genetic diversity. The 38 genotypes were grouped into seven clusters. Correlation studies revealed that the principal yield determining components in Basmati rice are number of days to panicle initiation, number of days to 50% flowering, height of plant at harvest, number of panicle bearing tillers, number of paniclesl/m2 ,1000 grain weight, aroma, kernel length before and after cooking, alkali value and awnness. While selecting genotypes for higher yield potential, emphasis should be given for compara- tively long vegetative period, short period from panicle initiation to 50 percent flower- ing and dwarf plant type. A selection model was formulated consisting of the characters namely. Yield/ha, num- ber of days to panicle initiation, height of plant at harvest, number of panicles/m2 , alkali value and elongation ratio. Basmati culture 385 and UPR-BS-92-4 are identified as superior genotypes among the entries studied.Item Identification of cherry tomato genotypes from f3 segregants of intraspecific cross(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2019) Pamarthi Vinod; Jayalakshmi, V GItem Variability in horsegram(macrotyloma uniform(Lam) verdc): under open and partially shaded conditions(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2019) Swathy Sivan; Arya, KItem Genotypic evaluation and in vitro multiplication of anthurium (Anthurium andreanum linden) hybrids(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2019) Anand, S; Beena Thomas