PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Droughts are a significant cause of reduced rice yields in South Asia, particularly in rainfed areas, where they affect over 23 million hectares of cultivated land. The prediction is that 15 million hectares of flooded-irrigated rice crops in Asia will become drought-prone by the end of 2025. This present study used a Malaysian commercial established variety, the MR219, which possesses high yield potential but is drought sensitive, as a recurrent parent and was screened with four selected genotypes (IURON 6, IURON 18, MR219-4, and DULAR) as donor parents of drought tolerance. The objectives of the present study are to screen and identify the most potentially tolerant rice genotypes and identify link foreground markers that respond to drought among parental plants. The sensitivity of rice genotypes to drought stress was observed, where DULAR recorded the highest score of leaf rolling, which was grouped in the most sensitive genotypes, followed by MR219 as susceptible genotypes; meanwhile, MR219-4 and IURON6 were intermediate ranking, while IURON 18 was less sensitive (moderately resistant) genotypes according to leaf rolling score which was negatively correlated with stomatal conductance. It was found that out of 21 linked/functional markers that were screened for polymorphism, five (RM201, RM28148, RM511, RM3392, and RM520) showed polymorphism between the two parents. The RM511 functional marker linked to IURON18 was tested and polymorphic between the two parents. The rice variety IURON 18 was identified as a valuable source for creating drought-resistant rice through marker-assisted backcrossing.