Peerreview C.4 (Mutagenic effects of gamma rays on soybean ( Glycine max L.) germination and seedlings)

Abstract

Narrow genetic diversity is a main problem restricting the progress of soybean breeding. One way to improve genetic diversity of plant is through mutation. The purpose o f this study was to investigate effect of different dose of gamma rays as induced mutagen on physiological, morphological, and anatomical markers during seed germination and se edling growth of soybean . Seeds of s oybean cultivars Dering - 1 were irradiated with 11 doses of gamma rays (0, 5, 10, 20, 40, 80, 160, 320 , 640, 1280, and 2560 Gy [Gray] . The research design was arranged in a complete ly randomized block design in three repl icates. Results showed that soybean s eed exposed at high doses (640, 1280, and 2560 Gy) did not survive more than 20 days, the doses were then removed from anatomical evaluation. Higher doses of gamma rays siginificantly reduced germination percentage at t he first count and final count, coefficient of germination veloc ity , germination rate index, germination index, seedling height and seedling root len gth , and significantly increase d mean germination time, first day of germination, last day of germination, and time spread of germination. However, the effects of gamma rays were varies for density, width, and length of stomata . The L D 50 obtained based on survival percentage was 314.78 Gy. It can be concluded that v ery low and low doses of gamma rays (5 - 320 Gy ) might be used to study the improvement of soybean diversity. Key words : seedling, stomata, morphological diversity