Composition of Metabolites in Swamp Rice Varieties to Stress Tolerance Screening

Abstract

Rice is an important food and produces metabolites which play several roles in the defense of the plant against abiotic and biotic stress. The development of stress tolerance variety is an importance for rice production. This study aims to analyze the metabolites of rice straw extract using Gas Chromatography-Mass Spectrometry (GC-MS). The analysis was carried out with 10 rice straw extracts at the flowering stage, while a total of 78 compounds were identified from the extract. The number of compounds in each variety ranged from 12-23. Fatty acid was the most dominant compound with 37%, followed by ester 26%, and steroid 14%. Palmitic, linoleic, and oleic acid were fatty acids found in many varieties. In addition, ethyl palmitate and 2-ethylhexyl hydrogen phthalate were also detected in all extracts. Based on the results, the highest content found in all varieties was 2-ethylhexyl hydrogen phthalate, except for Inpara 7 and 8 which predominantly contain linoleic acid. Inpara 4, 3, and 5 were included in one cluster that has a higher 2-ethylhexyl hydrogen phthalate, but a lower palmitic and linoleic acid content. The fatty acid can be used as one of the potential criteria in screening varieties for tolerance to stress, especially cold temperature, salinity, and blast disease.