Cobalt 60 (60Co) Gamma Ray Irradiation for Genetic Improvement of Edamame Plant Growth and Yield (Glycine max. (L) Merril) M2 Generation

Abstract

This study aims to examine the value of genetic diversity and heritability in the agronomic character of the M2 generation of Ryoko variety edamame plants and obtain the M2 generation of genjah-aged edamame plants that can adapt well to lowlands. The study used a single plant, with 288 plants planted, with each dose of 48. One treatment factor used in this study is the dose of 60Co gamma-ray irradiation consisting of 6 levels: 0 Gy, 100 Gy, 200 Gy, 300 Gy, 400 Gy, and 500 Gy. The results showed that 60Co gamma-ray irradiation influenced the germination percentage of edamame plants. The results of 60Co gamma-ray irradiation also affect the diversity of qualitative characters of edamame plants, especially in the leaf shape component. However, it does not influence the flower color and growth type components. The diversity of edamame plants caused by the results of 60Co gamma ray irritation impacts the shape of edamame leaves. The results of 60Co gamma-ray irradiation affect the agronomic character of edamame plants, especially in the growth and production components. Plant growth components include plant height, number of leaves, number of branches, flowering age, and harvest age. The elements of crop production include number of pods, weight of 100 seeds, and number of seeds per pod. The results of 60Co gamma-ray irradiation affect the genetic diversity of Generation M2 edamame plants, with the emergence of diverse phenotypes in each individual. Generation M2 edamame plants of the Ryoko variety grown in lowland areas have different genetic diversity values in each agronomic character observed. The value of the coefficient of genetic diversity in these characters ranges from 4.29% - 10.74%. On the other hand, the results of 60Co gamma-ray irradiation cause a decrease in protein levels in edamame. The highest average amount of protein content was shown at the 100 Gy dose of 18.05 g, and the lowest average at the 500 Gy dose of 16.12 g. The protein content of edamame seeds at 100 Gy had the highest protein content but showed no difference with the dose of 0 Gy (Control).  In general, the productivity of edamame plants is determined by genetic characteristics and environmental factors. Potential yields on edamame plants can be achieved if the plant does not experience interference with biotic and abiotic factors during the growing period.