ABSTRACT

Field experiment was carried at the Michael Okpara University of Agriculture, Umudike farm in 2016 season with the aim of determining the mutagenic effect of X-ray on the plant height, number of leaves, land leaf area of brown varieties and dark brown varieties ofCajanus cajan L. (Pigeon pea). Seeds of the two varieties were subjected to the X-ray radiation of 1 mgy, 2 mgy, 4 mgy, 6 mgy and 8 mgy respectively to find the replicate optimum dosage for the actual experiment for the two varieties. 1 he data obtained were subjected to linear regression analysis. The result showed that the effective doses for the two C. cajan varieties. For brown varieties 4 mgy and 8 mgy with 24.33 cm and 22.05 cm compared with 1 mgy (17.2 cm), 2 mgy (20.7 cm), 6 mgy (19.9 cm) and control (20.9 cm), in dark brown varieties 2 mgy (24.33 cm) and 6 mgy (22.3 cm) compared with 1 mgy (20.5 cm), 4 mgy (22.3 cm) compared with 1 mgy (20.5 cm), 4 mgy (18.3 cm), and 8 mgy (17.6 cm) and control (20.9 cm). Data obtained at 2, 4, 6, 8, 10 and 12 weeks after planting (WAP) were subjected to analysis ofvariance (ANOVA) in a Randomized Complete Block Design (RCBD) with 3 replicates for evaluation of their growth parameters. The result obtained on the plant height at the different weeks of data collection indicated that x-ray irradiation had significant effect on the plant compared to the control. Generally, plant irradiated with the low dose (2 mgy and 4 mgy) showed higher readings in growth parameter in brown varieties while the plant irradiated with higher dose of 6-8 mgy showed lower readings in growth parameters. Also the result presented indicated significant increase in the number of leaves which was obtained by visual counting ofthe leaves every two weeks in the two varieties as a result of the x-ray doses as compared with the controls example brown varieties of 4 mgy 25 and 8 mgy 23 while control is 20 leaves. In dark brown varieties 2 mgy 24 and 6 mgy 22 while control is 20 leaves. Significant effects were recorded on the leaf area plant on the C. cajan as a result of the exposure examples in brown varieties 4 mgy (6.19 cm2), 8 mgy (10.26 cm2) while control was (10.26 cm2). In Dark brown varieties 2 mgy (7.23 cm2), 6 mgy (6.64 cm2) while control was (5.93 cm2). It was generally observed that exposing the seeds of C. cajan to x-irradiation had positive effects on the parameters investigated.