Effects of Gamma Irradiation on Some Growth Traits and Yield Attributes of Pigeon Pea ‘Fiofio’ [Cajanus cajan (L.) Mill sp.]

Abstract

Effects of Gamma Irradiation on Some Growth Traits and Yield Attributes of Pigeon Pea ‘Fiofio’ [Cajanus cajan (L.) Mill sp.] Conventional breeding methods such as mutation breeding could lead to an improvement in the genetic variability in local varieties. The objective of the study was to evaluate the effect of gamma irradiation on the growth traits and yield attributes in two pigeonpea landraces (Cajanus cajan (L.) Millsp); white and brown varieties with the native name "fiofio" as used in the eastern part of Nigeria. Seeds of the landraces were obtained from the germplasm collection of the Department of Genetics and Biotechnology, University of Calabar, Nigeria. These seeds were irradiated with 0, 200Gy, 400Gy and sown in a plot measuring 10 × 10 meters at the University of Calabar Experimental Farm during 2011 growing season. A Randomized Complete Block Design (RCBD) was adopted during the planting. The result obtained revealed that percentage seed germination was not significantly affected (P>.05) by the gamma irradiation when compared to the control. But at the varietal level, white variety seeds exposed to 200Gy gamma irradiation recorded the highest percentage germination. The growth traits and yield attributes showed there were significant differences (P< .05) in all parameters studied except percentage germination while all seeds exposed to 400Gy did not survive more than two and half  months after germination. It was observed that there were variation between the two varieties under study, brown pigeonpea treated with 200Gy were more adversely affected as white pigeonpea treated with 200Gy was the overall best performing variety even when compared to both white and brown controls. This vividly revealed that gamma irradiation sufficiently encourages the improvement of these crops.