Evaluation and clustering of rice cultivars tolerance to salt and drought stresses using morpho-physiological and biochemical indices

Salinity and drought are the primary sources of osmotic and oxidative stress that have a deleterious effect on plant cell metabolism, globally limiting rice productivity. This study aimed to identify local salt and drought-tolerant rice genotypes for use as parental lines in a multistress-tolerant breeding program. The stability indices and relative values of growth, as well as biochemical contents, were used to determine substantial genotypic variations in salt and drought stress responses. Root length and leaf area under both stress conditions showed a significant positive relationship with proline, glutathione, and phenolic contents (r > 0.50–0.84). Cluster analyses classified rice genotypes into three major clusters: susceptible (IR29), tolerant (11 genotypes, including a salt-tolerant Pokkali), and highly tolerant (Hawm Prachinburi; RD45). RD45 has been classified as Thailand’s deepwater rice; therefore, RD45 has multistress tolerance and will be a potent elite-resistant donor in conventional and molecular breeding programs for multistress-tolerant rice. © 2023, The Author(s), under exclusive licence to Korean Society of Crop Science (KSCS).