Growth performance, yield, and proline content of two local cultivars of black rice irradiated by gamma rays for drought resistance

One of the critical effects of climate change on the agricultural environment is drought stress. This study aimed to determine the growth, yield performance, and proline content of black rice local cultivars Bantul, Boyolali mutant M2 at various doses of gamma rays and the proline content of mutant M3 during drought stress. The experiment used a Completely Randomized Design (CRD) with the factor dose of gamma-ray irradiation (0 Gy, 100 Gy, 200 Gy, and 300 Gy), applied in both paddy fields and polybags to observe and compare the growth, yield, and proline content of black rice plants with the control treatment (0 Gy). Laboratory test results showed that Boyolali and Bantul cultivars irradiated at 100 Gy and 200 Gy, had the highest proline content, which increased under drought stress conditions in both cultivars. At 100 Gy, the average plant height and the number of productive tillers of black rice of Boyolali and Bantul cultivars were the highest, and the diversity of the two local cultivars at this dose was higher than at other irradiation doses. Applying 100 Gy and 200 Gy gamma-ray irradiation doses on the Boyolali cultivar significantly affected the panicle length character and the number of seeds per panicle. For the Bantul cultivar, panicle length and the number of seeds per panicle at an irradiation dose of 200 Gy showed significantly different results. The conclusion is that a reduced amount of gamma-ray irradiation can enhance the growth, yield, and proline content of M2 black rice