Improving Salt Stress Tolerance in Cucumber (Cucumis sativus L.) by Using Triacontanol

Salinity is an ancient environmental phenomenon and reflected as the most important process of land degradation. It is widespread at variable degrees across the world. A sand culture study was conducted in order to investigate the performance of exogenously applied triacontanol on two tolerant (Green long and Marketmore) and two sensitive (Summer green and 20252) genotypes of cucumber (Cucumis sativus L.) under salinity stress (NaCl 50 mM). The foliar application of triacontanol was carried out @ 0.20, 0.40, 0.60, 0.80, 1.00 and 1.20 mg L-1. Salinity caused significant reduction in growth rate, gas exchange and other physiological attributes. Results revealed that triacontanol seemed to relieve the harmful impact of salt stress by improving morpho-physiological attributes and decreasing membrane leakage. Genotypes Green long and Marketmore performed better under salt stress regarding all studied parameters than Summer green and 20252. However, foliar feeding of triacontanol significantly enriched the efficiency of sensitive genotypes under saline conditions. The highest values of different attributes of cucumber plants were observed with foliar application of 0.80 mg L-1 triacontanol. Hence, triacontanol can be effectively used as a mitigating agent to alleviate phytotoxic effects in plants under saline stress.