Growth and Agronomic Performance of Advance Rice Mutant Lines (Oryza Sativa L.) Derived from Ion Beam Irradiation for Drought Tolerance Under Reproductive Stage

Water scarcity is a serious issue for rice production affecting rice growth and productivity. Drought stress impairs a variety of molecular, biochemical, physiological, morphological, and ecological features and processes in rice plants. This study evaluated the effect of drought on agro-morphological traits among four advance rice mutant lines induced by ion-beam irradiation in comparison with drought resistant variety, NMR151 and NMR152 and drought susceptible variety, MR219. The experiment was carried out at Sekinchan, Selangor during the off season (Mac-May 2021) and main season (September – December 2021) under drought stress condition. Advanced mutant lines show a promising result as most recorded lower reduction than MR219 and some may even better than the drought-tolerant varieties (NMR151 and NMR152). By performing Pearson's correlation analysis, strong negative relationship between unfilled grain per panicle (UFGP) and the spikelet fertility (SF) is observed and grain yields positively and significantly correlate with yield contributing factors (panicle length (PL), number of tiller (TN)). Further research on the improvement of a drought-tolerant genotype under different drought conditions using ion beam irradiaotion is necessary to enhance rice productivity and food security. (author)