Suitable dose of 60Co γ-ray for mutation in Roegneria seeds

Abstract

Seeds from six accessions of three species of Roegneria were radiated with 60 Co c-ray at different doses (50, 100, 150, 200, 250, 300 and 400 Gy). Following these treatments, germination energy, germination rate, seedling height, plant height, plant survival, and seed set were observed. Plant survival was highly correlated with seed- ling height (R 2 ( 0.91, P \ 0.01) and seed set (R 2 ( 0.82, P \ 0.01). The semi-lethal dose of each accession, calcu- lated using a 'Multi-target single-hit' model, ranged from 60 to 173 Gy. The most suitable absorbed doses for each accession were deduced from these data. The suitable doses for Roegneria kamoji, Roegneria ciliaris and Roegneria japonensis were 65-100 Gy, 63-150 Gy and 80-170 Gy, respectively. According to the range of suitable doses, R. kamoji (Pr87-88-353) was the most sensitive to radiation, and R. japonensis (88-89-267) was the most resistant to radiation. Suitable doses of R. ciliaris were close to that of R. kamoji (ZY1007). This research provides preliminary guidelines for radiation induced mutagenesis in Roegneria.