ABSTRACT

Groundnut is a self-pollinated crop and an important oil seed crop that possesses limited variability. This present study was aimed at ascertaining the effects of x-ray mutagen on the morphological and molecular attributes of groundnut (Arachis hypogaea L.) varieties. Morphological and molecular attributes of groundnut varieties were carried out on three groundnut varieties {Nwerente (NW), Red gwongworo (RG) and Red kampala (RK)} with two treatment levels 1 and 6; 1 and 4; 2 and 8 of x-ray doses respectively, which were determined and selected from a dosimetry analysis on treated seeds with 1 mGY, 2 mGY, 4 mGY, 6 mGY and 8 mGY levels of x-ray irradiation. The seeds were sown each in five replications in Completely Randomized Design (CRD). The primary data needed for this study were obtained through experimental observations ofplant height, stem girth, leaf area, number ofleaves, fresh and dry weight ofplant. For the molecular attributes, the young leaves were selected at random from two levels of treated variety and one control for gene extraction, gel electrophoresis and DNA extraction. In the physiological attributes, the interaction mean for leaf area was highest with RG (control) at 8.22 cm2, plant height with RG (control) at 36.13 cm, stem girth with RK (control) at 0.48 cm and number of leaves with RG (control) at 188.30. The interaction mean ofthe agronomic characters for fresh pod weight was highest with RG at 1 mGY of 242.46 g, plant fresh weight with RG (control) at 569.82 g, fresh biomass with RG atl mGY of 742.82 g, plant dry weight with RG (control) at 139.36 g, pod dry weight with RK at 1 mGY of 95.13 g and dry biomass with RG (control) at 224.27 g. Three RAPD primers (OPB-02, OPB-14, and OPH-05) were used to determine the quality ofbanding patterns. These primers showed occurrence ofpolymorphism of amplified clear banding pattern on the plates with the 3 varieties of groundnut (A. hypogaea L.). The result showed that x-radiation has major beneficial effect on groundnut at lower doses (control and 1 mGY). The dendogram result showed close similarity between the irradiated samples indicating that mutation actually occurred. Hence, x-ray irradiation can be used to induce mutation in groundnut at various levels of irradiation in mutation breeding. Also, the use of x-radiation as a pre-treatment tool for seed crop production should be done in dose guided manner so that injury levels on crops can be minimized