Morphological, physiological, and biochemical changes of eggplant (Solanum melongena L.) in response to salinity stress

Salinity is a significant challenge for agricultural development, particularly in dry and semi-arid regions. The numerous benefits of soilless cultivation have led to the expansion of these systems, especially in such areas. In this study, an experiment investigated the effects of accession and salinity stress on the morphological, physiological, and biochemical characteristics of eggplant. The experiment was designed as a factorial using a randomized complete block design with three replications. The first factor was accession at ten levels [FLT10 (V1), FLT22 (V2), FLT46 (V3), FLT E635 (V4), FLT E9012 (V5), M-AK (V6), MM00007 (V7), MM00197 (V8), MM00960 (V9), and MM01010 (V10)], and the second factor was salinity at four levels as sodium chloride [2 (control), 4, 8, and 12 dS/m]. The results revealed that accessions V4, V7, and V10 exhibited lower electrolyte leakage in leaf cells and greater cell membrane stability, indicating their higher tolerance to salinity stress. Glycine betaine, total protein, and the enzymes superoxide dismutase, peroxidase, and catalase were higher in the leaves of accessions V4, V7, V8, and V10, and lower amounts in accessions V1, V2, V3, V5, V6, and V9. The increase in these traits among the first group suggests a better defensive mechanism of the accessions under salinity stress. Moreover, enzyme activity increased with the rise in salinity level and the dominance of the accession. Based on the findings and considering the increasing salt levels in greenhouse irrigation water, selecting the superior accession can enhance plant growth under saline conditions.