نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار گروه باغبانی دانشکده کشاورزی دانشگاه تبریز
2 استاد گروه علوم خاک دانشگاه تربیت مدرس
3 مربی پژوهش مرکز تحقیقات کشاورزی و منابع طبیعی استان آذربایجانشرقی
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Salinity of soil and water is a serious problem affecting the growth and performance of plants in Iran. A pot experiment was conducted to asses the physiological effects of NaCl salinity on the olive trees growth. Four rates of NaCl concentrations (0, 50, 100, 150 mM) factorially combined with three olive trees cultivars. The experiment was based on completely randomized design with four replications. The plants were cut and vegetative characteristics such as leaf area, fresh and dry weight of leaves and the concentration of Na and K were measured at the end of the experiment. The rates of both photosynthesis (Pn) and transpiration were recorded during the growth of the plants using a photosynthesismeter (IRGA). The results showed that the growth of the plants in terms of leaf area, height and leaf fresh weight reduced as the salinity increased. However, the growth reduction of Manzanilla and Zard cultivars was more pronounced as the salinity increased. The rate of Pn tended to be lower in the high salinity treatments in all cultivars. The highest (1.8 µmol.m-2s-1) and lowest (1.0 µmol.m-2s-1) photosynthesis rate at high salinity were observed in Mission and Zard, respectively. Symptoms of toxicity as marginal necrosis on the leaves caused by salinity were initiated two months after applying salinity in Manzanilla and Zard cultivars. The concentration of Na in the leaves at high salinity (150mM) was 78% (Mission) and 83% (Zard and Manzanilla) compared with their controls. A positive relationship was found between K/Na and Pn rate, suggesting that the reduction in K concentration either by low uptake or the reduction of K/Na ratio has a remarkable effect on Pn rate. Reduction in growth of olive trees in saline conditions was a result of the reduction in leaf area, K/Na and Pn rate. It can be concluded that Mission can tolerate up to EC value of 15 dS.m-1 and 150 mM NaCl in seedling stage
کلیدواژهها [English]