| Mutagenic efficiency of individual and combined treatments
of Sodium Azide and Hydrazine Hydrate in bread wheat A. S. LARIK Department of Agronomy and Range science, Gassim College of Agriculture, King Sand University Saudi Arabia Induction of useful mutations in bread wheat (Triticum aestivum L.) has gained tremendous interest in the last two decades owing to an increasing awareness of the potential of this method for creating genetic variability. In addition to physical mutagens, attempts have been made by the research workers (AUGUSTINE et al. 1975; AWAN et al. 1980; KHAN, 1981; KONZAK et al. 1975; NILAN et al. 1976) to determine the most effective and efficient chemical mutagen for the induction of desirable traits in crop plants. As a result, an extensive array of highly effective mutagenic agents are now available. The present work on the effects of sodium azide (NaN3) and hydrazine hydrate (HZ) in two hexaploid wheat genotypes has been undertaken with a view to study the mutagenic-sensitivity in respect of seed germination and survival, pollen and seed fertility. Materials and Methods About fifty seeds per treatment of two hexaploid wheat varieties viz., Al-Samma and Hinta Madina were presoaked in distilled water for about 16 hours at 20 + or - 1C prior to treatment with different concentrations of sodium azide and hydrazine hydrate (Table 1). The concentrations of azide and HZ were prepared using standard potassium phosphate (KH2PO4) buffer pH-7. Presoaked seeds were placed in freshly prepared azide and HZ solution of each concentration for 3 hours at a constant temperature of 20 + or - 1C. During the treatment the flasks containing the solution and the seeds were frequently shaken to ensure sufficient aeration. In combination treatments, the seeds were soaked first in sodium azide for 3 hours and after being thoroughly washed in water, were immersed in HZ solution for 3 hours. For control only buffer solution without azide and HZ was used. After completion of treatment the treated seeds were washed for one hour in running tap water and sown in 12 inches pots along with control in a randomized design in three replicates in the greenhouse of the Department of Agronomy and Range Science, Gassim College of Agriculture, King Saud University, Saudi Arabia. The M1 generation was studied for the following parameters to determine the relative effects of individual and combined treatments on (1) Germination and seedling height on 10th day (2) Survival of seedling at maturity (3) Pollen and seed fertility. The mean values of 20 plants randomly selected from each treatment were considered for seedling growth. Germination and seedling height was determined according to the methods described by MYHILL & KONZAK (1967). Pollen fertility (stainability) was determined by staining pollen grains in a solution introduced by ALEXANDER (1969) and the seed fertility was calculated on the total population basis for each treatment. |
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