Priming, a Promising Practical Approach to Improve Seed Germination and Plant Growth in Saline Conditions

Salinity as a major constrain of plant productivity affects growth and development at any stage of growth cycle. Under saline conditions, rapid and uniform germination of plants would be necessary to achieve enhanced quality and potential yield. In such situation, seed priming could be an important approach to increase plant germination, growth and consequently yield. Priming is defined as seed presowing in solutions that allow them to imbibe water to improve the first stage of germination; however, this prevents radical protrusion through seed coat. Seed priming improves establishment in many plant species, and include hydro-priming, osmo-priming, halo-priming, thermo-priming and hormo-priming. Overall, accelerated biochemical and physiological process such cell division and starch hydrolysis, induced I±-amylase activity, greater germination rate, less Na+ and higher K+ accumulation and induced antioxidative system might be some mechanisms for salinity tolerance in primed plants. Since shortage of water availability due to osmotic stress is the first phase in salt stress, so one of the major mechanisms for improved germination and growth in primed seeds is accelerated water imbibition under saline conditions. In this paper, different seed priming strategies are examined and comprised in different plants growing in saline conditions. Since different types of seed priming have positive effects on germination, emergence, growth, yield as well as biochemical traits and quality of plants, it seems that seed priming could be promising approach for improved salinity tolerance in future world with changed climate. More researches on detail of seed priming for each agent is needed for each plant.