Water Stress, Heat, and Salinity in the Physiological Quality of the Seeds

Abstract

Plant seeds, being sessile, are simultaneously exposed to favorable or adverse conditions from sowing to harvest. The physiological quality of the seed is affected by the type of biotic and abiotic stress to which the mother plant is exposed, especially in the stages of embryogenesis, development and seed filling. Therefore, the behavior of their progeny will be reflected when the seeds are capable of maintaining acceptable viability standards with a high-germination potential to generate a normal seedling and establish themselves without difficulties under field conditions. Most of the species cultivated under abiotic stress conditions reduce their physiological quality; however, some species are salt dependent, and prolonged absence of NaCl in the soil inhibits seed development, results in lower seed quality and thus limits progeny-seedling growth as is the case of Suaeda salsa, and typical annual extreme halophytic herb with succulent leaves develops well and produces high-quality seeds when grown under high salinity conditions. Consequently, the response of the plant to adverse factors depends on the genotype and its stage of development at the time of stress, the duration and severity of the type of stress and the environmental factors that cause it. Depending on the severity and duration of the stress, plants could activate mechanisms to adapt or tolerate abiotic stress conditions at the molecular, morphological, physiological and cellular levels.