ALLEVIATION OF SALINITY STRESS IN LETTUCE DURING GERMINATION BY SEED PRIMING

Abstract

Using seed priming as a tool to overcome salinity stress conditions on lettuce Lactuca sativa L. (White Paris cv.) was studied. Seeds were primed in 5 different priming agents (PEG, KNO3, NaCl, CaCl2, Mannitol) plus the control treatment (without priming) then germination under laboratory conditions using different salinity levels, i.e. 0.00, 1000, 3000, 5000 and 7000 ppm was evaluated. Results indicated that primed seeds had a higher germination percentage than unprimed seeds under saline stress regardless of priming agent. Seed priming also reduced days required to 50% germination and promoted rapid and uniform germination under adverse conditions. Germination percentage and germination performance index were decreased with increasing saline stress while, uniformity of germination and days required to 50% germination were increased with increasing salinity levels. The low salinity level of 1000 ppm enhanced seed germination and seedling growth Lettuce seed germination showed high response to seed priming under salinity conditions; the most effective agents were CaCl2 , PEG and Mannitol. It could be concluded that seed priming agents have promotional effects on lettuce seed germination under salinity stress conditions