اثر ساليسيليك اسيد و آسكوربيك اسيد بر رشد دانهال هاي پسته تحت شرايط تنش شوري

چكيده انگليسي :

111Effect of Salicylic Acid and Ascorbic Acid on Growth of Pistachio Seedlings Under Salt Stress Nasim Bastam N Bastam@yahoo com 28 January 2012 Department of Horticultural Science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Assoc Prof B Baninasab bbanin@cc iut ac irAbstractSalinity is a common abiotic stress factor that seriously affects crop production in some parts of theworld particularly in arid and semi arid regions Irrigation with poor quality water is one of the mainfactors that lead to salt accumulation and as a result decrease in agricultural productivity Pistachio nuttrees Pistacia vera L have been grown commercially in Iran for many years Despite pistachio has beenclassified as salt tolerant plant poor quality of irrigation water in association with salt build up soils hasreduced the yields of pistachio over recent years The defense mechanisms of salicylic acid SA andascorbic acid ASA in plants against biotic and or abiotic stress suggests alleviation and amelioration ofsalt stress in plants A greenhouse pot experiment was therefore conducted to test whether the applicationof SA and ASA can mitigate the deleterious effects of salt stress on vegetative development in Ghazvini pistachio seedlings The treatments consisting of NaCl at four salt levels 0 30 60 or 90 mM and fourdoses of SA and ASA each at 0 0 1 0 50 or 1 00 mM The layout was as a 4 4 factorial experiment ina complete randomized design with four replications and three seedlings per replication The resultsshowed that injury rating value IRV of pistachio seedlings were found to increase significantly as thesalt concentrations were raised After exposing the seedlings to salt stress those that did not receive SAand ASA indicated typical salt injury symptoms at a moderate level while seedlings treated with 0 50 and1 00 mM SA and 0 5 mM ASA were slightly damaged Salt stress significantly decreased vegetativegrowth parameters stem length leaf number and areas shoot and root dry weight in pistachio seedlings SA and ASA ameliorated the adverse effects of injury caused by salt stress and improved vegetativegrowth parameters Increasing the concentration of NaCl caused to increasing leaf electrolyte leakage andproline content and lowered relative water content RWC in pistachio seedlings Application of SAsignificantly declined leaf electrolyte leakage and proline content and increased RWC compared with thecontrols SA and ASA also improved relative leaf chlorophyll content RLCC and chlorophyllfluorescence ratio Fv Fm and increased photosynthetic capacity as compared with the controls Theapplied NaCl caused to accumulating Na and abating K in leaves and roots of the pistachio SA andASA decreased Na accumulation and increased K accumulation in leaves significantly compared withthe controls the results showed significant correlations existed between and among these physiologicalindices and the morphological parameters These correlations suggested that IRV were positivelycorrelated with leaf electrolyte leakage proline contents and Na contents of leaves and roots butnegatively correlated with RLCC RWC Fv Fm ratios net photosynthetic rate stomatal conductance stem length leaf area shoot and root dry weights and K contents of leaves and roots Therefore it couldbe concluded that SA and ASA ameliorated the adverse effects of injury caused by salt stress throughpreventing decreases in RLCC RWC the Fv Fm ratio and net photosynthetic rate and suppressingincreases in leaf electrolyte leakage proline contents and Na contents of the leaves of pistachioseedlings As SA and ASA are readily available it could be used to prevent growth losses due to saltstress and may have significant practical application Key Words Pistacia vera L salicylic acid ascorbic acid Salinity physiological and photosynthetical parameters

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اثر ساليسيليك اسيد و آسكوربيك اسيد بر رشد دانهال هاي پسته تحت شرايط تنش شوري

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