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Subject: Plant Breeding × Author: Manjula, M × End date: 1996 × Start date: 1996 × Type: Thesis ×
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    ThesisItemOpen Access
    Gametocidal properties of certain chemical in rice
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1996) Manjula, M; KAU; Ibrahim, K K
    A pot culture experiment was conducted at Instructional Farm, College of Horticulture, Vellanikkara, Kerala during summer 1995 to study the gametocidal properties of three chemicals viz., ethrel, maleic hydrazide and streptomycin in two varities of rice. The study aimed at induction of variable levles of male sterility using these chemicals, with minimum interactions with other factors viz., stage, concentration and variety and also without adversely affecting spikelet fertility and plant growth characters like panicle exsertion. The chemicals were sprayed at concentrations of 4000, 6000 and 8000 ppm at stage-1 (spiketet differentiation stage) or stage-2 (pollen mother cell formation stage) in Annapurna, a short duration variety and Athira, a medium duration variety. The pollen spikelet sterility were observed in main and subsequent panicles. Pollen sterility differed with chemical, concentration and variety in main panicle and with all factors including stage of application in subsequent panicles. The effect of a chemical interacted significantly for pollen sterility with other factors viz., concentration and variety in main panicle and concentration and stage in subsequent panicles. The treatments involving maleic hydrazide were the most effective inducing pollen sterility upto 99.3 per cent. Ethrel was moderately effective in inducing maximum pollen sterility of 48.9 per cent in Annapurna with 4000 ppm at stage-1. Streptomycin failed to induce pollen sterility irrespective of stages and concentrations. Maleic hydrazide produced male sterility in a dose dependent manner. It caused more sterility in main panicle in Annapurna but in susequent panicles in Athira. Pollen sterility to a large extent was due to deformed anthers containing low or no pollen production in MH treated plants. High pollen sterility induced by the chemical was aasociated with high sterility of spikelets (upto 99.7%). Besides, it adversely affected plant height, panicle emergence and panicle exsertion. MH at 4000 ppm appeared to be the most ideal treatment for population improvement programme considering its effects on not only pollen sterility but also other important characters including spikelet sterility. On the other hand, in hybrid rice programme that require almost complete male sterility, MH at 8000 ppm at stage-1 or at 6000 ppm at stage-2 appeared to be more suitable.