Inducing drought tolerance in greenhouse grown Juglans regia by imposing controlled salt stress: The role of osmotic adjustment

摘要: Abstract Micropropagated walnut plantlets (Juglans regia) are usually grown in the greenhouse to obtain a suitable size prior transplantation. Meanwhile, maintaining under optimal growing conditions for long durations makes them more susceptible harsh environmental such as drought. This study was aimed at inducing drought tolerance one-year-old micropropagated ‘Chandler’ by preconditioning exposing controlled salt stress (100 mM Na2SO4, 100 mM CaCl2, KNO3, 50 mM Na2SO4+50 mM CaCl2+50 mM and 30 mM of each solution half strength Hoagland’s nutrient solution). Water relations, osmotic adjustment gas-exchange plants’ were measured after phase understand defense responses. Then, irrigation plants stopped 30 days above mentioned parameters examined again determine among preconditioned plants. The treatments induced leaves imposing stress. With adjustment, transpiration rate decreased water use efficiency (WUE) enhanced. Furthermore, exhibited slower loss from their detached leaves. After period, showed greater leaf area, content, WUE, membrane thermostability index chlorophyll concentration, compared control These observations mainly due stronger adjustment. Proline major osmolyte involved active Na2SO4 proved be most successful treatment which caused accumulation proline induction J. regia.