Gamma irradiation effects on seed germination, growth and morphological traits of kemiri sunan (Reutialis trisperma (Blanco) Airy Shaw)

Abstract

Kemiri Sunan is a biodiesel producing tree that has an ecological function as a reforestation plant since it can adapt to the marginal, dry and ex-mining land. It is necessary to increase the genetic diversity of kemiri sunan through mutation in order to support its breeding program. Dried seeds of Karmindo1 and M03 varieties were exposed to gamma sources with doses ranging from 50 to 1000 Gy to evaluate the effect of gamma irradiation on the germination and growth of kemiri sunan seeds. The percentage of germination, as well as physiological parameters of seedlings (shoot length and number of leaves) decreased with increasing irradiation doses. However, the two varieties showed a difference in sensitivity responses to gamma rays. The recommendation doses for the two varieties are 100 – 200 Gy and 50 – 100 Gy for Karmindo1 and M03 respectively. No morphological variation was found in seedlings except for one mutant with early branch formation. The development of this plant is important, not only as an alternative source of renewable energy, but also as one of the crops that can adapt to the threat of global climate change such as drought.