Application of SNP Markers to Identify Genetic Variation on Mutant Lines of Adan-Krayan, Special Local Rice from North Kalimantan

Abstract

Adan rice, a local rice from the Krayan highland of North Kalimantan is marked by its fine taste that consumers like. However, this rice can only be planted once a year due to its long lifespan. Efforts have been made to develop a short-lived version of Adan, to enable it to be planted twice a year. Adan Kelabit was initially exposed to gamma radiation, which produced several mutants. Field selection identified eight mutants with shorter lifespans than the Adan. In this study, these eight mutants were observed further. SNP markers were carried out to confirm the occurrence of mutations, while observations of agronomic characters and grain quality were carried out to determine the most promising lines. The molecular study showed mutations found in all chromosomes of the mutants and differentiated them from the original Adan, with the similarity level ranging from 0.746 to 0.843. However, this closeness is not correlated to the dosage of the gamma rays applied. The majority of the mutants have shorter plant height and higher yield potential. On average, the mutant is 11.5% shorter on heading date, 22.69% higher on tiller number, 27.14% higher on grain weight, and 26.64% higher on other parameters of yield potential. Apart from the shorter heading date, each mutant has its superiorities. The A25 and A28 mutant lines have much higher yield potential while maintaining the same level of amylose content as the Adan rice. These two mutants can be considered for further development or dissemination for farmer adoption.