SCREENING OF MARDI RICE ACCESSIONS FOR SALINITY TOLERANCE AT SEEDLING STAGE BASED ON GROWTH PERFORMANCE AND MOLECULAR ANALYSIS

Salinity is one of the important abiotic factors that can interfere with rice production in many rice-growing areas. In Malaysia, many major rice growing areas are located near to coastal saline land. Therefore, identification of potential rice accessions for future breeding program for salinity tolerance is crucial. A total of 28 rice accessions were selected for this study. The screening was performed at EC=12dSm-1 under controlled environment at seedling stage. Shoot length, root length, biomass, percentage of surviving seedlings, and leaf injury score were used to assess seedling growth performance. Whereas, the molecular analysis was performed using eight Simple Sequence Repeat (SSR) markers for salinity tolerance. Significant variations were shown for all the recorded traits among the rice accessions, treatments, and environments. Lui Oui, Boro Shunga, and Khao Tah Haeng showed the highest shoot length under salinity condition with the readings at 34.61 cm, 36.47 cm, 35.45 cm, respectively. The rice accessions also showed higher biomass production and lower leaf injury score. The molecular analysis observed the average PIC value was 0.741, with values ranging from 0.545 to 0.907. The SSR marker, RM10720 was found to be superior for analysis of genetic diversity as shown by the highest PIC value. By comparing the two dendrograms, four rice varieties namely Lui Oui, Sinandomeng, Khao Tah Haeng, and Kao Saard 108 were clustered with Pokkali in both dendrograms. Considering the performance under salinity condition and confirmation with molecular analysis, Lui Oui, Sinandomeng, Khao Tah Haeng, and Kao Saard 108 are considered potential donors that can be used in breeding programmes for the development of salinity tolerant rice cultivars. The SSR markers can be used in screening and identification of salinity tolerance genotypes.