Low-energy heavy-ion-beam-induced mutation of novel high-yielding drought-tolerant Thai Jasmine rice

Abstract

To respond to the global warming challenge to local agriculture, we applied a low-energy heavy ion beam as novel biotechnology to improve crop drought tolerance. Dehulled seeds of Thai Jasmine rice, Khao Dawk Mali 105 (KDML105), a popular Thai rice variety, were bombarded by a nitrogen ion beam with energy of tens-keV and fluences in an order of 1016 ions/cm2. The resulting mutagenized rice was obtained, selected, and further advanced until phenotypically stable. Mutagenized lines were screened for drought tolerance in the seedling and reproductive stages under an artificially created drought condition in comparison with KDML105 and the drought-tolerant reference variety, CT9993, using both subjective and quantitative parameters. We advanced the mutants up to M8 generation for stabilization and found a mutant line named HyKOS22, which displayed higher tolerance to the drought condition than KDML105 and CT9993 and produced a higher crop yield than KDML105. Genetic changes in HyKOS22 were confirmed by molecular biology analysis.