ABSTRACT

Three accessions of Amaranthus hybridus L. were exposed to x-irradiation to detennine its mutagenic effect. The accessions were collected from different localities (Ezi Ogidi, Ogbunike, Oye Olisa) in Anambra State. The study adopted a Randomized Complete Block Design (RCBD). A preliminary test was carried out to detennine the optimum mutagen dosage. Each accession was divided into six parts to include five treatments and one control. The treatments are 1 MGY, 2 MGY, 4 MGY, 6 MGY and 8 MGY. The accessions were planted and the plant height was measured weekly for one month. Statistical analysis was carried out and the dosimetry was taken from the points on the graph where the plants did best. Each accession was then divided into three parts to include two treatments and one control for the main experiment. Ezi Ogidi accession was treated with 5 MGY and 6 MGY, Ogbunike accession was treated with 1 MGY and 4 MOY while Oye Olisa accession was treated with 5 MOY and 6 MGY. Each treatment including the control (0 MGY) was replicated four times. Seeds germinated three days after planting and growth parameters (plant height, leaf area, and leaf number) were taken weekly for ten weeks. The flower weights (fresh and dry) of the accessions were also compared using bar graph. Data were subjected to Analysis of Variance (ANOVA) and HSD (Highest Significant Difference) was used to separate the means at 95% Family-wise Confidence Level. The result for Ezi Ogidi accession showed that the plant height has the mean ± se of 65 ±9.41,60 ± 9.12°, and 56.6 ± 8.06 for the control, 5 MGY and 6 MGY respectively, the leaf area showed the mean ± se of 975 ± 154°, 875 ± 137, 853 ± 138 for the control, 5 MGY and 6 MGY respectively, the leaf number has the mean ± se of 17.1 ± 1.05, 16.7 ± 1.01° and 16.7 ± 1.02° for the control, 5 MGY and 6 MGY respectively. Ogbunike accession showed that the plant height has the mean ± se of 54.9 ± 7.7, 57.5 ± 7.76\, 67.2 ± 8.06° for the control, 1 MGY, and 4 MGY respectively, the leaf area showed the mean+ se of ~ 729 ± 108, 400 ± 58.0, 584 ±-87.5° for the control, 1 MGY and 4 MGY respectively, the leaf number showed the mean ± se of 16.7 ±1.01, 16.4 ± 0.98, 16.6 ± 1.0° for the control, 1 MGY and 4 MGY respectively. Oye Olisa accession showed that the plant height has the mean ± se of 66.8 ± 8.34°, 67.5 ± 10°, 54.9 ± 8.66 for the control, 5 MGY and 6 MGY respectively, the leaf area showed the mean ± se of 503 ± 70.1, 632 ± 85.8°, 572 ± 73.7° for the control, 5 MGY and 6 MGY respectively and the leaf number has the mean ± se of 17.2 ± 1.06, 16.9 ± 1.03° and 16.8 ± 1.02° for the control, 5 MGY and 6 MGY respectively. The result from the growth parameters showed that there is no significant difference among the treated plants and their controls. The accessions were also subjected to Random Amplified Polymorphic DNA Analysis (RAPD). Five primers were used for the analysis but only two primers gave polymorphism. The primers are T-06 and T-20. It was noticed that Oye Olisa accession treated with 5 MGY and 6 MGY has three bands of 1500 bp, 1400 bp, and 800 bp with primer T-06 which is not noticed in the control. Ogbunike control sample had many missing or absent bands on primer T-06 unlike the treated samples. Ogbunike accession treated with l MGY had one band on primer T-20 which is absent in others. Ezi Ogidi accession had two polymorphic bands of 400 bp and 200 bp with primer T-06.