Physiological responses of double haploid rice lines to salinity stress in the targeted environment

Abstract

Salinity stress is a significant limitation in rice production, particularly in targeted environments where physiological indicators are employed. This study aimed to identify key physiological traits associated with salinity tolerance in rice under specific field conditions. Ten rice genotypes were assessed under normal and saline conditions in a field experiment conducted in Eretan. The physiological parameters measured included chlorophyll content, relative water content, malondialdehyde, and proline levels. Analysis of variance indicated a significant genotype-environment interaction for chlorophyll content, suggesting its potential as a selection criterion for salinity tolerance. The relative decrease in chlorophyll content was utilized to identify tolerance traits, with the tolerant check, Pokkali, exhibiting a lower relative decrease than the sensitive check, IR 29. Correlation analysis demonstrated a strong association between the relative reduction in total chlorophyll and chlorophyll b with productivity and the levels of other photosynthetic pigments. These findings imply that maintaining a stable chlorophyll content under salinity stress is essential for rice genotypes to adapt and sustain photosynthetic efficiency. This study underscores the importance of integrating physiological traits with agronomic data to enhance the precision of screening for salinity tolerance in rice breeding programs aimed at improving productivity in saline environments.