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2005 - 200912010 - 20182
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Author: Gayathri, G × Author: KAU × Start date: 2000 ×
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    ThesisItemOpen Access
    Heterosis breeding in sesame (Sesamum indicum L.).
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2011) Gayathri, G; KAU; Dijee, Bastian
    The study entitled ‘Heterosis breeding in sesame (Sesamum indicum L.)’ was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara. The objectives of the study were to collect and evaluate different genotypes of sesame for morphological traits and yield attributes, to identify useful parents producing heterotic crosses and developing hybrids in sesame. The study also intended to develop male sterile lines in sesame through interspecific hybridization with Sesamum malabaricum. Sesamum indicum and Sesamum malabaricum accessions were collected from Kerala and Tamil Nadu and evaluated for their morphological traits. Wide range of variation was noticed for characters like plant height, number of days to flowering and seed yield per plant which contributed maximum to genetic divergence. The genotypes studied were grouped into six clusters. High genotypic coefficient of variation (GCV) was recorded for number of capsules per plant, plant height, seed yield per plant and number of branches per plant. High heritability with high genetic advance as per cent of mean was recorded for number of days to flowering, plant height, number of branches per plant, number of capsules per plant and seed yield per plant. This indicates that the characters are governed by additive gene effects and selection for these traits will be effective. Association analysis revealed that seed yield per plant was correlated to plant height, number of capsules per plant and number of days to flowering. Path coefficient analysis indicated maximum positive direct effect by number of capsules per plant, capsule length, plant height and 1000 seed weight on seed yield per plant. In order to develop hybrids, fourteen parents were selected based on the per se performance of the genotypes. They were crossed in line X tester mating design. Forty eight hybrid combinations obtained were raised in the field along with the parents and evaluated for their heterosis and combining ability effects. Parental genotypes AVTS-06-5, AVTS-06-10, IVTS-06-12, KYM-1, Tilak and TMV-6 were identified as high combiners based on general combining ability (gca) effects. Two combinations viz. AVTS-06-5 X KYM-1 and IVTS-06-12 X TMV-3 had significant values of per se performance, specific combining ability (sca) effects and standard heterosis for seed yield per plant. They can be evaluated for their hybrid vigour over locations and seasons. The crosses AVTS-06-5 X TMV-3, AVTS-06-5 X TMV-6 and TCR 3279A X KYM-1 have been identified as potential cross combinations for isolation of promising segregants as the parents involved in these crosses had high significant gca effects for seed yield per plant but the hybrids recorded non significant sca effects. Interspecific hybridization between S.malabaricum and S.indicum was attempted to develop male sterile lines. Seed set was noticed in three interspecific hybrids which failed to germinate due to embryo abortion. Hence these embryos were rescued and raised in vitro to obtain the hybrids.
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    ThesisItemOpen Access
    Enhancing fruit set and yield of tomato (solanum lycopersicum L.) in polyhouse using artificial pollination and growth regulators
    (Department of Vegetable Science, College of Agriculture , Vellayani, 2018) Gayathri, G; KAU; Rafeekher, M
    The present investigation entitled “Enhancing fruit set and yield of tomato (Solanum lycopersicum L.) in poly house using artificial pollination and growth regulators” was conducted at the Department of Vegetable Science, College of Agriculture, Vellayani during 2017-2018. The objective of the study was to enhance the fruit set and yield of tomato under poly house through artificial pollination and application of plant growth regulators. The tomato variety “Akshaya” was raised in polyhouse and subjected to three artificial pollination methods, seven growth regulator treatments and their combinations along with control. The artificial pollination methods were A0 (Control), A1 (Shaking), A2 (Air Blowing), A3 (Vibratory Pollination) and growth regulator treatments were G0 (control), G1 (PCPA 10 mgL-1), G2 (PCPA 20 mgL-1 ), G3 (PCPA 30 mgL-1), G4 (GA3 20 mgL-1), G5 (PCPA 10 mgL-1 + GA3 20 mgL-1), G6 (PCPA 20 mgL-1 + GA3 20 mgL-1) and G7 (PCPA 30 mgL-1 +GA3 20 mgL-1). Artificial pollination methods were executed daily during morning hours and plant growth regulators were sprayed on to the flower trusses at fortnightly intervals during the entire flowering period. The artificial pollination methods and its interaction with growth regulators did not significantly influence vegetative characters like plant height, height at flowering, primary branches plant-1, leaf length and leaf width. Combination of Gibberellic acid (GA3) and Parachlorophenoxy acetic acid (PCPA) improved vegetative growth of plant by increasing plant height, leaf length and leaf width against control and application of individual growth regulators. Application of PCPA 30 mgL-1 + GA3 20 mgL-1 resulted in maximum plant height (324.90 cm) which was on par with combination of PCPA 20 mgL-1 + GA3 20 mgL-1. Application of PCPA 30 mgL-1 + GA3 20 mgL-1 produced longer (37.85 cm) and wider (23.65 cm) leaves. Vibratory pollination significantly improved fruit set (67.35 %) compared to other methods and control. Shaking or blowing air on flower trusses could not improve fruit set significantly. Application of growth regulators did not influence days to first flowering, days to fruit set and flowers cluster-1 but significantly improved inflorescence plant-1, fruit set and pollen viability and reduced number of flowers with exserted stigma. Highest fruit set (66.34 %) and pollen viability (64.20 %) was obtained by application of PCPA 30 mgL-1 which was on par with PCPA (10 mgL-1 and 20 mgL-1) in combination with GA3 20 mgL-1. Maximum inflorescence plant-1(17.27) was obtained for PCPA 30 mgL-1 + GA3 20 mgL-1 which was on par with PCPA 20 mgL-1 + GA3 20 mgL-1 (15.57) and GA3 20 mgL-1 (15.17). PCPA 20 mgL-1+ GA3 20 mgL-1 significantly reduced flowers with exserted stigma (25.72 %). PCPA 30 mgL-1, GA3 20 mgL-1 and PCPA 10 mgL-1 + GA3 20 mgL-1 also were on par. Pollination with vibrator significantly improved fruits cluster-1 (6.60), fruits plant-1 (45.69) , fruit length (6.63 cm), fruit girth (15.02 cm), yield plant-1(1311.75 g) and yield plot-1 (2.90 kg m-2 ) and number of seeds fruit-1 (131.94) compared to other methods and control. Shaking and air blowing did not significantly influence any of the fruit characters. PCPA 30 mgL-1 + GA3 20 mgL-1 produced maximum fruits plant-1 (45.45) , fruit length (6.90 cm), fruit girth (15.65 cm), yield plant-1 (1487.50 g) and yield plot-1 ( 3.47 kg m-2). PCPA 20 mgL-1 + GA3 20 mgL-1 was also equally effective for all these characters. All growth regulator treatments except PCPA 10 mgL-1 + GA3 20 mgL-1 were equally effective in improving fruit weight. However, all growth regulator treatments except GA3 20 mgL-1 lowered the number of seeds fruit-1. Growth regulator application did not influence fruits cluster-1 and thousand seed weight. Fruit quality parameters like total soluble solids, titrable acidity, vitamin C and lycopene were not significantly influenced by any of the treatments and their interactions. Application of growth regulators PCPA 30 mgL-1 + GA3 20 mgL-1 and PCPA 30 mgL-1 induced more abnormalities in fruits. The results indicated that application of PCPA 20 mgL-1 + GA3 20 mgL-1 on flower clusters at fortnightly intervals during the flowering period not only enhanced inflorescence plant-1, pollen viability, fruit set, fruit size and yield of tomato but also reduced the number of flowers with exserted stigma and number of seeds fruit-1 while vibratory pollination improved fruit set, fruit size, yield and number of seeds fruit-1, which can be used selectively for improving fruit production and seed production of tomato under poly houses in Kerala.
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    ThesisItemOpen Access
    Standardisation of in vitro propogation techniques in thathiri (Woodfordia fruticosa (L.) Kurz.)
    (College of Horticulture, Vellanikkara, 2005) Gayathri, G; KAU; Arya, K
    The present study ‘Standardisation of in vitro propagation techniques in thathiri [Woodfordia fruticosa (L.) Kurz.]’ was undertaken in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara during 2003-2005 through the conduct of two experiments viz. (i) direct regeneration and (ii) regeneration through callus mediated organogenesis. SH medium was found to be the best basal medium for in vitro culture of thathiri. Shoot tips were the best explants for direct organogenesis and nodal segments were used as explants for indirect organogenesis. Surface sterilization of the explants was done by soaking them in 70 per cent alcohol for two minutes followed by soaking them in 0.1 per cent HgCl2 for five minutes. One subculturing three days after inoculation checked the polyphenol interference. Multiple shoot induction was obtained when shoot tips were cultured in medium supplemented with BAP 0.5 mg/l and NAA 0.5 mg/l. The shoot elongation was best in media with BAP 0.2mg/l. Callus formation in the nodal explants of thathiri was best in media with NAA 0.5 mg/l while callus regeneration was superior in media containing BAP 0.5 mg/l and NAA 0.5 mg/l. The best response in rooting was observed in media with IBA 0.2 mg/l. Rooted plants were hardened in earthen pots containing sterile sand and covered with polythene cover. After four weeks they were transferred to larger pots in the main field.