physiological response of pear (pyrus communis cv.dargazi) to salinity stress under in vitro conditions

this study was conducted to find out the influence of in vitro salinity on growth parameters shoot length, number of leaves, number of new buds, the chlorophyll, chlorosis and necrosis and absorption of sodium, chloride, potassium, nitrogen and phosphorus of pear (pyrus communis cv. dargazi) in vitro propagated shoots. the experiment was conducted as a complete randomized design with 5 salinity levels; (control), 40, 80, 120 and 160 mm of sodium chloride in 2013 at zanjan university, zanjan, iran. different mentioned parameters were assessed after 6 weeks of culture. shoot length and leaf number per explant decreased and number of chlorotic and necrotic leaves increased with increasing salinity. increasing salinity levels also decreased nitrogen and potassium content of plant tissues while their sodium and chloride contents increased. phosphorus was not affected by salinity.