Evaluation of salt resistance in two pistachio species with regard to growth indices of seedlings, seedling survival, and some ecophysiological characteristics.

摘要

To investigate the salinity effects on growth indices of pistachio seedlings, three pot experiments were conducted. The source of salinity for experiment 1 was NaCl, while NaCl + CaCl2 + MgCl2 was used for experiments 2 and 3. Experiments 2 and 3 consisted of three split plot designs with the Na:Ca:Mg ratios of 5:1:1, 1:5:1 and 1:1:5, respectively. In experiment 1, main plots consisted of electrical conductivities of irrigation water (ECiws) including 0.5, 2, 4, 8 and 16 dS m-1, whereas in experiment 2, it changed to 0.5, 2.5, 4.5, 8.5 and 16.5 dS m-1. With respect to the results obtained from experiments 1 and 2, ECiws of 0.5, 4.5 and 8.5 dS m-1 with significant differences were selected for the third experiment. In experiments 1 and 2, the seedlings of seven Pistacia vera cultivars (Badami-e-Riz, Momtaz, Akbari, Kalleh-Ghuchi, Ohadi, Ahmadaghaei and Sarakhs) and P. mutica (Baneh) were allocated in subplots. In the third experiment, three P. vera cultivars (Badami-e-Riz, Momtaz and Ohadi), with different salt tolerances which had been selected from previous experiments, were used. To determine the resistance of pistachio cultivars in with respect to seedling survival, experiment 4 was conducted. Materials and methods in experiment 4 were similar to experiment 2. In experiments 1, 2 and 3, the medium culture of each pot was irrigated with saline water to near field capacity at two-day intervals up to 25, 20 and 15 times, respectively. In experiment 4, salinity treatments were continued up to 70% of leaf damaging. In experiment 5, the effects of salinity on pistachio seedlings in regards to chlorophyll-meter figures, proline contents and the ratio of damaged leaves were studied. In experiments, the number of experimental units was 2076. In experiments 1, 2 and 3 growth indices (e.g. total dry weight) of seedlings in higher ECiws were reduced significantly. Lower levels of salinity (2.5 and 4.5 dS m-1) partly increased the total dry weight of seedlings in 5:1:1 ratio; whereas, in 1:1:5 ratio, in each level of salinity, this character decreased considerably. In experiments 1 and 2, Badami-e-Riz was selected as the resistant cultivar, and Ohadi and Momtaz as moderately sensitive cultivars. With ECiws of 4.5, 8.5 and 2.5 dS m-1, seedling survival decreased significantly where the ratio of salts were 5:1:1, 1:5:1 and 1:1:5, respectively. In experiment 4, Badami-e-Riz and Ohadi were screened as resistant cultivars to NaCl, CaCl2 and MgCl2 (all ratios)..