Shading Alleviates Damage of Short Term Salinity and Protects Leaf Pigments in Sweet Cherry

Abstract

Salt stress negatively influences fruit yield and quality in trees. In addition to environmental stresses, excess energy from sunlight possesses harmful effects on plant metabolisms. Here we reveal the effects of shading on short term salinity stress in cherry plants. Salinity and shading treatments were introduced approximately two months after planting. Three shading levels (40%, 60%, and 80%) were applied. To induce moderate salinity stress, 35 mM NaCl (sodium chloride) was utilized for one month. Many morphological and physiological aspects and chlorophyll metabolism were evaluated. We found that the plant growth, stomatal conductance and chlorophyll biosynthesis were significantly retarded under salinity during a month. However, shading treatments alleviated the salinity damage. Moreover, salt stress hindered the biosynthesis of chlorophyll at Mg-Proto IX step. Shading treatments mitigated salinity damage associated with decreasing air and leaf temperature and preventing the loss of chlorophyll and the precursors and increasing anthocyanins. The results of the study showed that shading treatments possessed a protective effect on short term salinity in cherry plants.