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Subject: Horticulture × Author: KAU × End date: 1992 × Start date: 1992 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Seed dormancy in groundnut
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1992) Presanna Kumari, K T; KAU; Narayanan Namboodiri, K M
    The present investigation entitled "Seed dormancy in groundnut" was undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1987-1990 using the 419 genotypes received from ICRISAT, Hyderabad. The 419 genotypes possessed varying levels of dormancy at the time of harvest. Genotypes with varying degrees of dormancy were present in all the three botanical groups, viz., hypogaea, fastigiata and vulgaris. The dormancy period of genotypes ranged from 20 to 110 days. The hypogaea genotypes required longer period of rest. The nature of breakage of dormancy and the period of dormancy were found to be two independent phenomena. The factors for dormancy in groundnut were found to be residing in two distinct sites, the cotyledons and the seed coat (testa). Leaching improved the germinability of decoated seeds where as it failed to elicite germination in intact seeds. This indicates that germination inhibitors may be present in the cotyledons and testa retarded the removal of the same. Different genotypes responded differently to various presowing treatments. HgCl2 1, 1000 for five minutes was found to be the best treatment for breaking dormancy. The study of germinability of F1,F2 and F3(embryonic generation) seeds on the day of harvest indicated that dormancy was controlled by polygenes.
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    ThesisItemOpen Access
    Improvement of propogation efficiency of anthurium species in Vitro
    (Department of Horticulture, College of Agriculture, Vellayani, 1992) Sreelatha, U; KAU; Ramachandran, Nair S
    Attempts were made, to improve the propagation efficiency of Anthurium species through enhanced release of axillary buds and callus-mediated somatic organogenesis/embryogenesis, in the plant tissue culture laboratory of the Department of Horticulture, College of Agriculture, Vellayani during 1990-92. Four species of Anthurium namely, A. andreanum, A. crystallinum, A. veitchii and A. grande were selected for the study. Shoot tips from in vitro grown seedling were used as explants for the enhanced release of axillary buds. Cent percent survival was observed in all the cytokinin treatments. The maximum number of shoots (4.50) was observed with kinetin 2.0 mg/1 as well as BA 1.0 mg/1. Treatments with kinetin was free of callus growth. In treatments with BA and 2ip, callus growth was observed at the base of the explant. Treatments with Ms inorganic salts as well as sucrose did not influence multiple shoot formation. One fourth strength of MS major rutrients with full strength of micro nutrients was ideal for multiple shoot induction. Glucose produced less number of shoots than sucrose. One percent sucrose did not influence multiple shoot induction. The longest shoot (0.95cm) was observed at 0.4 percent agar. Light was necessary for the enhancement of axillary buds. In darkness, callus growth was observed, from which many adventitious shoots were produced. Segments of leaf, petiole, spathe, spike and inflorescence stalk were used a explants for callus initiation. Combinations of 2, 4-D and BA were efficient in initiating callus. In A.andreanum, 2, 4-D 0.08 mg/1 and BA 1.0 mg/1 was ideal for callus initiation. Combination of 2, 4-D, 0.2 mg/1 and BA 1.0 mg/1 was the best for callus initiation in A. veitchii. In A. grande, the best callus initiation was observed with 2, 4-D 0.5 mg/1 and BA 1.0 mg/1. Modified MS medium with reduced salt concentrations was ideal for callus initiation in all the species. Inositol when reduced to half concentration (of the normal) influenced callus initiation. The leaf explant (with the smallest vascular bundles) among the other explants, had the highest number of cultures free of microbial contamination. Basal portions of leaf responded, better than the apical portions, to in vitro culture. Continuous darkness was necessary for callus initiation and growth. MS medium with ¼ strength major nutrients was ideal for callus multiplication. Attempts,made on callus-mediated somatic embryogenesis, were not successful. Shoot regeneration and growth of the shoots were the best in MS medium with BA 0.5 mg/1 and IAA 2.0 mg/1. No rooting treatments were required as the shoots rooted spontaneously. Plantlets survived, better than micro shoots, exvitro. The plantlets required less hardening treatments. Sand was the best potting medium for planting out. Nutrient solutions when used for the irrigation the plantlets, had a negative influence on the survival of plantlets. Treatments with VAM (Glomus constrictum and G. etunicatum) was beneficial for the survival as well as growth of the plantlets. Cytological examinations of the root tip squashes made on random number of plantlets, at planting out, showed a normal diploid chromosome count. Attempts, to correlate the biochemical properties with in vitro response, of different explants as well as species, were not successful. Based on the existing facilities of the plant tissue culture laboratory of the department of Horticulture, College of Agriculture, Vellayani, the cost of single anthurium plantlet was worked out to be Rs.3.00/=.
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    ThesisItemOpen Access
    Ethnobotany of medicinal plants used by tribes of Kerala
    (Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1992) Sudhadevi, P K; KAU; Aravindakshan, M
    nvestigations were carried out on the Ethnobotany of medicinal plants of the tribes of Kerala in the Centre for Advanced Studies on Humid Tropical Tree Crops and Environmental Horticulture attached to College of Horticulture, Vellanikkara during 1988 – 1991. The study included documentation of ethnomedicines, botanical description and propagation of selected five rare plants and screening of selected plants for antimicrobial activity. The Malayan tribe of the selected localities, viz., Chimminy, Marottichal, Sholayar, Vazhachal and Vazhani were selected for the study. Ethnomedico – botanic information on 212 plant species, belonging to 184 genera of 73 families were documented. According to the magnitude of availability of information and paints, the localities could be ranked as Sholayar > Vazhachal > Marottichal > Chimminy/ Vazhani. Erosion of the knowledge and depletion of the flora as urbanization advances were observed. The tribe knew the remedy for almost all the common diseases. Single plant remedies were observed for alopecia (Nyctanthes arbortristis), bone fracture (Justicia gendarussa), paralysis (Cassia fistula), prolapse of the rectum (Mangifera indica), whitlow (Euphorbia antiquorum) and as analgesic (Thevetia neriifolia), antilactogenic (Jasminum pubescens) and diaphoretic (Oroxylum indicum). Maximum number of plants, either alone or in combination were used for eye diseases followed by diarrhoea and dysentery, loss of hair and snake bite. Plants used as animal and insect repellents and for cattle diseases were also documented. Information was also obtained on diagnostic and prophylactic plants. Use of Allium sativum along with Ocimum sanctum as a prophylactic for mumps, Allanthus excels for lalarial fever, and the leaves of Tragia involucrate for diagnosing pregnancy were very simple and worth mentioning. Plants were used in combination with other plants ; plant products like oils, jiggery, sugar, animals like chiken, crab and tadpole; animal products like butter, honey and milk; and inert materials like ash, clay and salt. Religious or magical rituals accompany the uses of certain plants. They also keep certain taboos about medicinal plants. Five rare plants, Alstonia venenata, Coscinium fenestratum, Habenaria latilabris, Rotula aquatic and woodfordia fruticosa were botanically described and illustrated. Feasibility of multiplication of these species under Vellanikkara conditions revealed that the easiest method of multiplication was through root cuttings in Coscinium fenestratum, pseudobulbs in Habenaria latilabris, hardwood cuttings in Rotula aquatic and seeds in Woodfordia fruticosa. In Alstonia venenata, the treatments tried were not successful. None of the ether and alcoholic plant extracts screened showed any antimicrobial properties while the essential oils from four plants showed remarkable traits in this aspect. Clove leaf oil was found to be inhibitory to all the bacteria and fungi tested . The inhibition was more compared to most of the antibiotics and fungicides available in the market. The essential oil of Coscinium fenestratum and Cinnamomum verum also showed fairly good antibacterial and antifungal properties. The essential oil of Alstonia venenata was able to suppress the growth of bacteria, though ineffective in the case of fungi. However, further in vivo studies are required in order to prove its efficacy in natural/experimental infections before its utility is advocated for field conditions. The information gathered revealed that the tribal community of Thrissur District has a traditionally self managed system of folk medicine. Comprehensive and systematic surveys and documentation are required in other unexploited areas also for gathering such valuable information before they are being lost.