Development and validation of a membership function-based evaluation system for salinity screening in rice

Salinity is a major abiotic stress that affects plant growth and development in rice. In this study, 37 genotypes along with 2 checks were screened for salinity at the seedling stage using hydroponics. Analysis of variance revealed a significant difference among genotypes for the recorded traits. Most studies have evaluated the salt tolerance based on the independent mean performance of traits. However, this study aimed to utilize membership function values which account for cumulative tolerance from all traits. Based on average MFV, three genotypes were classified as highly tolerant, four genotypes were classified as tolerant, 25 genotypes were classified as moderately tolerant, six genotypes were classified as susceptible, one genotype as highly susceptible. Simple linear regression analysis indicated total fresh weight is the reliable trait for salinity screening in rice at the seedling stage. Further, a multiple regression-based mathematical model was developed, which identified that a membership function-based evaluation system can be utilized for salinity tolerance grading. The identified highly tolerant and tolerant genotypes can be utilized for the improvement of salt tolerance at the seedling stage in rice.