تاثير قارچ هاي محرك رشد بر فعاليت آنزيمي خاك تحت كشت گياه كنجد [Seasamum indicum] در شرايط تنش خشكي

چكيده انگليسي :

The effect of growth promoting fungi on soil enzyme activity under cultivation of sesame Sesamum indicum in drought condition Javad Shafiey Jazy Javadshafiey@yahoo com 2016 5 18 Date of Submission Department of Soil Science College of Agriculture Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Dr mozhgan sepehri E mail msepehri@cc iut ac irSupervisor Dr Farshid noorbakhsh E mail Farshid@cc iut ac irAbstractDrought has been recognized as a primary constraint in limiting the growth and development of plants Itimpairs normal growth disturbs water relations and reduces water use efficiency in plants Drought stressat any growth stage also poses detrimental effects on morphological physiological and biochemicalprocesses in plants To maintain growth and productivity plants must adapt to stress conditions andexercise specific tolerance mechanisms of stress agents Plant modification for enhanced tolerance ismostly based on gene transformation however the nature of the genetically complex mechanisms ofabiotic stress tolerance and the potential detrimental side effects make this task extremely difficult Apromising alternative for improving plant drought tolerance is using the beneficial soil microorganismsincluding Plant growth promoting fungi PGPF This research was undertaken to investigate the effect oftwo PGPFs on some physiological characteristics nutritional status of sesame plant and also activity ofsome soil enzymes under drought conditions For this purpose a field experiment using a completelyrandomized blocks with three replications and treatments including fungal inoculation non inoculation Piriformospora indica and Glomus intraradices and drought levels include 55 75 and 85 of MAD Maximum available water depletion on the basis of combined analysis in Lavark Field IsfahanProvince was conducted The results showed that drought stress resulted in greater reduction of shootbiomass plant height number of leaves catalase activity relative water content membrane stabilityindex and concentration of nitrogen and iron in shoot part of non inoculated plants compared toinoculated ones The comparison of studied fungi indicates that only Glomus intraradicens increased theconcentration of phosphorus in the shoot part of plants significantly Each of the studied fungi showedtheir positive effect on different characteristics and also different drought stresses So that Glomusintraradicens increased phosphorus content at 75 MAD relative water content of leaf and nitrogencontent at 85 MAD and catalase activity membrane stability iron concentration shoot biomass andnumber of leaves at 75 and 85 MAD However P indica increased iron concentration and height ofshoot at 75 MAD shoot biomass and nitrogen content at 85 MAD and catalase activity membranestability relative water content of leaf number of leaves and urease enzyme activity at 75 and 85 MAD The studied fungi increased the activity of catalase and urease enzymes in all drought treatments However L asparaginase activity was not changed in response to experimental treatments drought andfungal inoculation In general the obtained results of this research indicate that drought is a limitingfactor for plants and PGPFs can improve plant tolerance to this environmental stress by improving plantnutritional status water content and activity of anti oxidant enzymes Keywords Drought Plant Growth promoting fungi PGPFs Sesame and Soil enzymes

شفيعي جزي، جواد

تاثير قارچ هاي محرك رشد بر فعاليت آنزيمي خاك تحت كشت گياه كنجد [Seasamum indicum] در شرايط تنش خشكي

قارچ اندوفايت , خصوصيات تغذيه اي گياه