1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Vegetative, Floral and fruit characters in mangosteen (Garcinia mangostana L.)(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1996) Ajay Alex; Sarah T GeorgeThe 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.Item Karyomorphology, Pollen sterility and seedset in Vetiver (Vetiveria zizanioides (Linn) Nash.)(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1989) Mini, K S; Viswanathan, T VInvestigations on karyomorphology, pollen sterility and seedset in Vetiveria zizanioides were undertaken using eleven cultivars of Vetiver, including North Indian type, South Indian type and one hybrid. The observations on plant morphology indicated no clearcut morphological features employable for exact identification of North Indian and South Indian types of Vetiver. The somatic chromosome number was observed constant in all cultivars ie. 2n = 20. However, the different cultivars differed cytologically with respect to chromosomal characters like size and shape, total chromatin content and meiotic configurations during different stages of division. Presence of meiotic abnormalities like bridges and laggards were observed in all cultivars with highest frequency in O D V - 4. This cultivar also showed high percentage of pollen sterility. A direct relationship between meiotic abnormalities and pollen sterility was noticed. Studies on seedset pattern of different cultivars revealed very low set, mostly nil upon selfing, while all the cultivars produced fairly high quantity of seeds upon open pollination.Item Induction of genetic variability in ginger (zingiber officinale rosc.) through in vitro fertilization(Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara, 2005) Rethidevi, A; Valsala, P AInvestigations on ‘Induction of genetic variability in ginger (Zingiber officinale Rosc.) through in vitro fertilization’ were carried out at the Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara during 2004-2005. Molecular characterization studies of the eight ginger cultivars -Z-0-78 (V1) Kodakara Local (V3), Kuruppampady (V4), Mahima (V5), Maran (V6), Rejatha (V7), Rio-de-Janeiro (V8) and Varadha (V9)- by RAPD using nine random primers revealed that the genetic variability among the cultivars very narrow in the range of 5 to 19 per cent. The cultivar Rio-de-Janeiro was distinct with maximum variability. The variability among the released varieties from IISR ranged from 5 to 10 per cent. The flowering season in ginger extended from August to November. The cultivars showed variability with respect to duration for initiation of flowering and flowering duration. The mean pollen fertility and viability among the ginger cultivars were 35.76 per cent and 8.11 per cent respectively. The autotetraploids had high pollen fertility and viability compared to diploids. The range of pollen viability in autotetraploids was from 12.03 to 15.68 (Z-0-78) and in diploids it was from 3.68 to 8.90 per cent. Among the diploids the released varieties Varadha, Mahima and Rejatha had more pollen fertility and viability. Attempts were made to refine the in vitro pollination technique with respect to basal media combination, growth regulators, vitamins and gelling agent. Studies conducted in the cross Varadha X Z-0-78 using placental pollination technique. The basal medium of half MS with 2X vitamins was superior to B5 medium. As gelling agent phytagel 0.18 per cent was superior to agar 0.65 per cent. Among the various plant growth regulator combinations tried the combination of picloram and BA was found to be best. The medium of half MS with 2X vitamins + 3 per cent sucrose + BA 2.5 mgl-1+ picloram 0.2 mgl-1 + 0.18 per cent phytagel was the best with respect to maximum ovule swelling, percentage of cultures with ovule development and percentage setting per culture. Seed set and seed development in various crosses involving autotetraploids and diploids were assessed. The parental combination between autotetraploids (Z-0-78 X Z-0-86) produced seeds with very good swelling in maximum number of cultures with maximum setting per culture. The parental combination Z-078 X Varadha and its reciprocal also favoured very good ovule swelling. The parental combination Z-0-86 X Varadha as well as Varadha X Mahima and their reciprocals produced seeds with good swelling. The size increase of the developing ovules after in vitro pollination was monitored from the day of pollination to 60 DAP. The size increase upto 15 DAP was rapid. At 60 DAP the ovules attained four-fold increase in size. The pollinated ovules cultured, in the course of maturation turned pink and later blackened. The seeds showed complete endosperm filling at 10 DAP. The soft and jelly like endosperm became hard by 20 DAP. Viability test with tetrazolium showed that the seeds were viable up to 50 DAP. Embryo was found to be seated towards the chalazal end and endosperm constitutes the major portion of the seed. Germination studies were conducted in a number of plant growth regulator combinations. The 60 days old seed derived from the parental combination of Kuruppampady X Z-0-78 showed radicle emergence in the medium of half MS + 3 per cent sucrose + 0.65 per cent agar + IBA 3.0 mg l-1. The seeds of parental combination Z-0-78 X Varadha germinated through somatic embryogenesis in the medium of B5 + 3 per cent sucrose + 0.18 per cent phytagel + 2,4-D 0.2 mg l-1 + BA 2.5 mg l-1 105 days after in vitro pollination. The germination was 10 per cent It was found that the seed coat was pushed apart by the callusing embryo and it developed globular somatic embryoids. Embryoids developed root and shoot poles in the same medium. The somatic embryoid is in the initial stage of development. Embryo culture studies with embryos excised from seeds of 15 to 60 DAP in various media combinations did not give positive response. Prolonged culturing may give positive results.Item Floral biology and compatibility studies in Heliconia(Department of Pomology Olericulture, College of Agriculture, Vellayani, 2005) Sanjeev, S J; Sheela, V LItem Genetic studies in brlnjal with relation to bacterial wilt resistance(Department of Agricultural Botany, College of Agriculture, Vellayani, 1983) Gopimony, R; Krishnan, Nair NItem Variability studies in seedlings of heliconia (Heliconia spp.)(Department of Pomology and Floriculture,College of Agriculture, Vellayani, 2011) Kadam Darshan, Shashank; Sheela, V L