Effects of Different Water Stress on Photosynthesis and Chlorophyll Content of Elaeagnus rhamnoides

Abstract We studied the response of Elaeagnus rhamnoides (Sea Buckthorn) to drought stress in a nursery. Photosynthesis and chlorophyll content under drought were change rather modest. Growth and physiological differences in response to drought were compared between four Sea Buckthorn seedlings treatments inhabited in the Qazvin provenance origin seeds in Mashhad city of Iran. The experimental design included four water regimes (100% of field capacity) and three blocks. Our experiments were under semi-controlled environmental conditions for four growing season. Four-month-old seedlings were examined with four different water regimes corresponding to 2, 4, 8, 12, dayʹs duration. At the end of watering regimes, Chlorophyll content and Photosynthetic of leaves was measured using SPAD, CCI (Chlorophyll Concentration Index) and A (Photosynthetic rate) by several devices. The A was positively correlated with SPAD and DS (Dry Stem) but negatively correlated with the CCI and DR (Dry Root) in all of treatments except 12 day irrigation. CCI was positively correlated with DR, in 2day treatment, with SPAD and DR in 8day with all of traits in 4day and 12 day but negatively correlated with others. There were significant negative correlations between SPAD with DR in first watering regime and DS in third watering regime. Between DR and DS were significant positive correlations only in 12day treatment but significant negatively correlated in 2day and 8day watering regime measured. We concluded SPAD and A were tolerated efficiently between 4day and 8day, then we can irrigate seedlings more than 4day and less than 8day treatment. Different watering treatments employ different strategy for physiological and morphological responses of this plant.