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19863
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Subject: Agriculture × Author: KAU × End date: 1986 × Start date: 1986 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Genomic relationship in vigna species
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1986) Neema, V P; KAU; Narayanan Namboodiri, K M
    Investigations on the genomic relationship in Vigna species were undertaken in the Department of Agricultural Botany, College of Horticulture during 1983-1985. Pure seeds of the two subspecies of Vigna unguiculata, viz. unguiculata and sesguipedalis were sown and crop raised. Direct and reciprocal crosses were made. Morphological and cytological investigations were done. It was found that the two subspecies easily crossable. In both the subspecies there was high prefertilisation shed. The chromosome number of subsp. unguiculata was 2n=22, of subsp. sesguipedalis 2n=24 and of F1 hybrid was 2n= 23. Both the parents and hybrid showed cells with laggards. Length of meiotic and somatic metaphase chromosomes was more in subsp. sesguipedalis, lowest in subsp. unguiculata and intermediate in their F1 hybrid. Both the subspecies and their hybrid had almost similar TF % which gave an indication of similarity in their karyotypes. Pollen fertility was more in subsp. sesguipedalis. Reciprocal difference was seen in the case of morphological characters like height of the plant, number of primary branches, internodal length, seeds per pod, seed colour and seed volume. However, these differences were not seen traceable in the cytology of the hybrid.
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    ThesisItemOpen Access
    Gamma ray induced polygenic variability in Bhindi
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1986) Ahmed, Regina; KAU; Krishnan, Nair N
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    ThesisItemOpen Access
    Biological effects of gamma rays and EMS in the M1 generation of red gram(Cajanus cajan L.)
    (Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1986) Jayanthi, S; KAU; Narayanan Namboothiri, K M
    The studies reported herein were undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during the period 1983-'85. Seeds of SA_1 variety of red gram (Cajanus cajan L.) were subjected to induced mutagenesis using five doses of gamma rays (10, 20, 30, 40 and 50 krad) and five doses of EMS (0.3%, 0.4%, 0.5%, 0.6% and 0.7%) and their biological effects on the M1 generation were studied. In the preliminary laboratory test it was found that the two presoaking times viz., 2 hours an d4 hours did not differ significantly. Same was the case with the two durations of chemical treatments viz., 6 hours and 8 hours. The three concentrations of the chemical viz., 0.5%, 0.75% and 1% tried did differ significantly. The LD50 value was obtained as 0.7%. Lower doses of both gamma rays and EMS stimulated seed germination. No dose dependance on the percentage of germination was noticed in the case of gamma irradiation while in the case of EMS, germination percentage proportionately decreased with increasing concentrations of the chemical. Gamma ray treated seed took longer time for germination compared to those treated with EMS. Reduction was observed in the survival percentage of seedling with increase in doses of gamma rays and EMS. Root length, shoot length and plant height were reduced by gamma rays and EMS, the rate of reduction being directly proportional to the increase in dose. Pollen and seed fertilities decreased linearly with increase in doses of both gamma rays and EMS. Among the two mutagens, EMS was more effective in reducing pollen and seed fertilities. Chlorophyll chimeras, in very low frequencies were observed only in the EMS treated population. Morphological variations noticed included dwarf plants, plants with crinkled leaves, those with reduced canopy size, those with prolonged as well as reduced flowering duration, those with lesser number of flowers and fruits. These morphological variations were restricted to EMS treated populations.