Responses of ‘Chandler’ Walnut Variety Grafted onto Different Rootstocks to Salt Stress

To investigate effects of salinity stress on growth, nutrient status, chlorophyll and water consumption, four different saline irrigation waters (S۰= ۰.۳ dS/m-۱ control, S۱=۱.۵ dS/m-۱, S۲=۳ dS/m-۱, S۳=۵ dS/m-۱) were applied to two-year Chandler saplings which were grafted on Juglans nigra L. (JN), Paradox (PR) and Juglans sieoboldiana L. (JS) walnut rootstocks. Three different salts including NaCl, MgSO۴, and CaCl۲ were used to prepare saline irrigations. Shoot length change rate (%) was varied between ۷۷.۵۷ (JN) to ۸۱.۸۳ (PR) for S۰ salinity treatments and between ۵۵.۶۰ (JS) to ۵۶.۸۴ (PR) for S۳ treatments. The plant diameter change rate (%) varied between ۷۵.۱۰ (JN) to ۹۹.۲۲ (PR) for S۰ treatments and ۶۰.۶۳ (JN) to ۸۰.۹۷ (PR) for S۳ treatments. Average of root length (cm) was between ۳۰.۷۵ cm (JN) to ۳۷.۵۰ cm (PR) for S۰ treatments, and ۸.۹۱ cm (JN) to ۲۱.۵۰ cm (PR) for S۳. Number of roots changed between ۱۹.۰۰ (JS) to ۲۲.۱۶ (PR) for S۰ treatments and between ۶.۴۱ (JN) and ۸.۰۸ (PR) for S۳ treatments. Sodium (Na) content (%) in S۳ was ۱.۴۱, ۱.۹۷ and ۳.۴۱ in JN, PR, and JS, respectively. Chloride (Cl-) content (ppm) for S۳ was ۰.۸۸, ۰.۹۹ and ۰.۹۱ in JN, PR, and JS, respectively. Ca/Na ratios of ۰.۴۳, ۰.۲۷ and ۰.۱۴ and K/Na ratios of ۰.۲۴, ۰.۱۲ and ۰.۱۰ were detected in JN, PR, and JS, respectively. Depending on leaf Na+, Cl- and K contents, K/Na and Ca/Na ratios, the ranking of salinity tolerance of rootstocks were determined as JN˃ PR ˃ JS.

کلیدواژه ها:

salinity ، walnut rootstocks ، plant growth ، abiotic stress