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1993 - 19963
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Subject: Floriculture and Landscaping × Author: KAU × End date: 1996 × Start date: 1992 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of time of planting and growth regulators on flowering and vase life of Gerbera jamesonii
    (Department of Pomology and floriculture and Landscaping, College of Horticulture,Vellanikara, 1993) Suma, P; KAU; Lila Mathew, K
    Studies were carried out in the Department of pomology and Floriculture, College of Horticulture, Vellanikkara, Thrissur, during 1991 – 93 to examine the effect of time of planting and growth regulators on flowering and vase life of gerbera. Four varieties, namely , Eoliet, Presley, Pritty and Sunbird and five treatments, viz., GA 50 ppm, GA 100 ppm, CCC 500 ppm, CCC 750 ppm and control, were tried. Varieties were found to have significant influence on both vegetative as well as the floral characters whereas the treatments did not have any significant effect on vegetative characters of the Gerbera cultivars in general, when evaluated in the first season. In the second season both varietal and treatment effects were not consistent. Variety Presley was found to be early flowering while Eoliet was late flowering. GA 50 ppm and GA 100 ppm hastened flowering whereas CCC 500 ppm and CCC 750 ppm delayed it. In general the longevity of flowers was maximum in varieties Eoliet and Sunbird. Variety Presley had the least longevity. Among the treatments, CCC 750 ppm and GA 50 ppm increased the longevity of flowers in field. Maximum number of blooms was produce by Presley and the minimum by Eoliet. In general GA 100 ppm and CCC 750 ppm increased the number of blooms. In general CCC 750 ppm, GA 50 ppm and GA 100 ppm had a significant positive influence on flower diameter. In general variety sunbird had the maximum stalk length and diameter, while Pritty produced the shorest stalks. CCC 500 ppm and CCC 750 ppm had the best effect on stalk length. Vase life was found to be significantly increased by GA 100 ppm and CCC 750 ppm treatments given to the plants. Five per cent sucrose + 20 ppm AgNO3 significantly increased the longevity of flowers in vase. Planting in June was found to be better than October planting with respect to vegetative as well as floral characters, especially for number of flowers and flower diameter. Among the varieties, with respect to growth and number of flowers, Presley was found to be superior. In the correlation studies flower number was found to have positive and highly significant correlation with plant height and leaf area whereas flower diameter had significant negative correlation with leaf area and stalk length. Petiole length, stalk diameter and leaf number had positive correlation with this character. Vase life had significantly positive correlation with fresh weight of flowers.
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    ThesisItemOpen Access
    Response of Gladiolus to Rapid Cloning Through in Vitro Techniques
    (Department of pomology and floriculture, College of horticulture,Vellanikkara, 1995) Sakkeer Hussain, C T; KAU; Geetha, C K
    Investigations were carried out to study the response of gladiolus to rapid cloning through in vitro techniques at the Department of Pomology and Floriculture and Plant Tissue Culture Laboratory of All India Co-ordinated Floriculture Improvement Project, College of Horticulture, Vellanikkara, during 1992-94. The main objective was to identify the most suitable explant and media combination for in vitro cloning. The explants used were corm axillary buds, cormel tips, inflorescence nodal segments (for enhanced release of axillary buds), inflorescence internodal segments, flower buds, flower bud bracts, root segments (for somatic organogenesis) and leaf segments (for somatic embryogenesis). The best season for the collection of corm axillary buds and cormel tips was from September to May. Surface sterilization of the explants could be effectively done with 0.1 or o.2 per cent mercuric chloride and the duration of treatment varied from I to25 minutes. Culture establishment of the corm axillary bud, cormel tip explants were better in MS medium supplemented with BAP ranging from 1.0 mg 1 -1 to 4.0 mg 1-1. The concentration of BAP required varied according to the stage of development of corms and cormels. Higher levels of BAP was ideal during early stages of development of corm and cormels. Of the different media (White’s, SH and MS) tried, MS medium was found to be the best culture establishment (Stage 1) when supplemented with 3.0 mg 1-1 BAP. Elongated shoots of Stage I were subjected to shoot proliferation (Stage 2). Multiple axillary bud production was very high when the MS medium was supplemented with BAP 1.0 mg 1-1 and NAA 0.5 mg 1-1 or BAP 2.0 mg 1-1 and NAA 0.5 mg 1-1. Callus production from the base of the elongated shoots were observed when the concentration of NAA increased in the medium. Of the different cytokinins (BAP, kinetin and 2ip) tried, BAP was found to be the best in Stage 2. Frequent subculturing onto the MS medium containing BAP 2.0 mg 1-1 and NAA 0.5 mg 1-1 increased the production of multiple axillary buds. These when transferred to the MS medium devoid of growth regulators resulted in elongation of shoots. The elongated shoots produced maximum number of roots in the MS medium containing 1.0 mg 1-1 IBA under the exclusion of light. However, early rooting was obtained in MS liquid medium devoid of growth regulators. Plantlet survival was maximum when treated with 0.2 per cent Bavistin immediately after removing from the culture vessels, followed by treatment with 0.2 per cent mancozeb and norfloxacin at the time of transplanting and post planting treatment with 1/10 MS solution and drenching with triadimefon 20.0 mg 1-1 at three days interval inside improvised mist chamber. Direct organogenesis could be obtained from immature inflorescence segments in modified MS medium supplemented with 15.0 mg 1-1 NAA and 3.0 mg 1-1 BAP. Among the various explants tried for callus mediated organogenesis, callus index was the maximum (400) when immature inflorescence segments were inoculated to the modified MS medium supplemented with NAA 15.0 mg 1-1 in 16 h photoperiod and also in the medium supplemented with 15.0 mg 1-1 NAA + 2.0 mg 1-1 BAP and kept under exclusion of light. The callus derived from inflorescence segments differentiated into shoots in the MS medium supplemented with 3.0 mg 1-1 BAP and also in the medium supplemented with 1.0 mg 1-1 BAP and 0.5 mg 1-1 NAA. Callus also could be obtained from flower buds and flower bud bracts. The callus derived from the corm axillary buds and cormel tip explants in Stage 2, differentiated in the basal MS medium devoid of growth regulators or supplemented with 20.0 ml 1-1 coconut water and also in the medium with 0.5 mg 1-1 BAP. The root segments (both in vitro and in vivo) produced callus in MS medium supplemented with 1.0 mg 1-1 NAA and the differentiation was obtained in the medium containing 3.0 mg 1-1 BAP an 1.0mg 1-1 NAA. Leaf segments failed to develop callus. However, the explants collected from the leaf covering the inflorescence boot leaf) when cultured in modified MS medium supplemented with 15.0 mg 1-1 NAA and 1.0 mg 1-1 BAP and incubated under darkness for three months developed somatic embryos. In vitro corm production was noticed in the cultures, if planting out was delayed. Earliest and large sized corm induction was made possible in elongated shoots of gladiolus from Stage 2 in Ms medium containing 5.0 per cent sucrose, 0.5 mg 1-1 NAA and 5.0 mg 1-1 triadimefon kept under etiolated condition. The size of the in vitro produced corms enlarged from 0.2 cm to 2.3 cm in the MS liquid medium containing 5.0 per cent sucrose and 3.0 mg 1-1 triadimefon.
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    ThesisItemOpen Access
    Vegetative, Floral and fruit characters in mangosteen (Garcinia mangostana L.)
    (Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1996) Ajay Alex; KAU; Sarah, T George
    The present investigations on the growth habit, phases of growth, flowering and floral biology, fruit development, seed viability and storage life of mangosteen were carried out in the Department of Pomology and Floriculture, College of Horticulture, during the period 1994-96. The studies indicated that shoot growth in mangosteen coincided with the main flushing season from June to August and with a second one from January to February. Maximum shoot growth was observed during July. The growth of the tree was slow, with an extension growth of 6.91 cm in an year. The tree had a monopodial orthotropic trunk meristem which showed continuous growth. Laterals exhibited plagiotropy, sympodial growth and sylleptic branching habit. Leaf arrangement was spiral in the seedling stage but distichous on the branches of mature tree. Emerging leaves which were purplish red, later changed to dark green. The flowering season was from December to January. But development was completed in 28 days. Flowers were female and borne terminally on branchlets either singly or in groups of two to four. Flower drop was meager. Peak anthesis period was between 17.30 and 18.00 hours. Flowers had four scarlet red sepals and four yellow petals each having imbricate aestivation. Androecium consisted of 18-20 staminodes. Gynoecium was syncarpous with five to seven carpels having single ovule in each locule on axile placentation. Style was short and had a five to seven fid capitate stigma at its end. Anthers failed to dehisce until flower opening but a few showed signs of dehiscence after anthesis. Stigma showed no signs of receptivity. Anthers produced numerous non viable pollen grains which failed to germinate in vitro. Different methods of pollination had no effect on fruit set. Initial set was high but a fruit drop of 41 per cent occurred during first month. Though fruit development was parthenocarpic and seed development parthenogenetic, seeds produced were viable. Therefore, mangosteen can be considered as an obligate agamosperm where proembryos developing from integuments of embryosac mature into embryos. Pulp development took place from 42nd day onwards. Average weight of ripened fruit was 100 g. The percentage contribution of pulp towards total fruit weight at ripening stage was 33.00 per cent as against 62.30 and 4.70 per cent in the case of rind and seed, respectively. Chemical composition of pulp showed a decreasing trend. Total sugars, reducing sugars, non reducing sugars and sugar : acid ratio increased upto harvest. Season of harvest coincided with South West monsoon. Stage of harvest was identified as 90 days after fruitset. Such fruits ripened normally in two days at ambient temperature and showed no difference in quality as compared to that of tree ripened fruit. At this stage, 25 per cent of the fruit skin developed a purple colour and scar formed at the stalk end was smooth, without any exudation of gum. Mechanical injury should be avoided during harvesting and handling to save fruits from Transluscent Flesh Disorder. Yield varied from 650 to 3350 fruits/tree. Number of segments, which was same as that of stigmatic lobes, ranged from four to seven. However, number of viable seeds ranged from zero to three. Fruits caught in the rain were severely affected with gamboges, a disorder, which accounted to about 33.82 per cent fruit loss. Exudation of yellow gum from the rind was the characteristic symptom. The fruit pulp also became yellow, gummy, corky, bitter in taste and inedible. Biochemical analysis showed that ripened fruit contained water 76.57, protein 0.5, citric acid 0.32, total sugars 17.02, reducing sugars 3.22, non reducing sugars 13.80, nitrogen 0.28, phosphorus 0.01, potassium 0.13, calcium 0.01 and magnesium 0.24 on percentage basis. Sugar : acid ratio, TSS and ascorbic acid content was 53.18, 27.00 0brix and 5 mg/100 g, respectively. β carotene was only in traces. Fruits stored under refrigerated conditions showed no quality deterioration and fruit loss even after one month of storage. Fruits kept in bamboo baskets lasted for a fortnight. Keeping quality of fruits even without any treatment was more than a week. During storage TSS, sugars and sugar: acid ratio decreased, whereas acidity increased with the storage period. Seeds varied in size and shape. Viability was very high when sown immediately after harvest. Storage reduced the viability and was completely lost by 35 days of storage. Seeds took 20 days for germination. Germination was hypogeal with single seedlings arising normally, but 10 per cent polyembryony with 2-4 seedlings/seed was also noticed.