盐胁迫对苹果矮砧P1生长及生理特性的影响

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Abstract：Toinvestigatethegrowthandphysiologicalresponseofdwarfingrootstocksundersaltstres，thisstudyprovides atheoretical basis forthetransitionofapplecultivationmodetohigh-density dwarfing rootstocksand sustainable developmentoftheappleindustryinSaline-alkaliregions.Usingtheself-rootedrootstockP1asthetestmaterial，ndfive different concentrations of NaCl solutions （0，25，50，75，and 100mmol⋅L-1 ）as three-day intervals fora total of 5 treatments， thebiomass，leaf androot morphology，chlorophyll content，root vigour，relativeelectricalconductivity （REC）， malondialdehyde （MDA）， osmoregulators，hydrogen peroxide （H2O2） ，superoxide anion （O2-）- ）content，and antioxidant enzyme activities are dynamically monitored.The results show that short-term 25mmol⋅L-1 salt stress treatment can promote chlorophyllsynthesisandundergroundrot growthinPl，andincreaserootantioxidantenzymeactivity.Butthecontentof O2-⋅ ，relativeconductivity （REC），soluble sugar （SS），andproline（Pro）slightlydecreaseorshow litle diffrence.With the enhancementofsalt stressthe leavesofP1 turn yellowandfellof，root growth androotvigour inhibit，the activityof antioxidant enzymesreduces，and the contentof H2O2. O2-. accumulates，which leadsto the intensificationofmembrane lipid peroxidation，the enhancementofcell membrane permeabilityand the increaseof osmoticregulating substances.In conclusion， under 25mmol⋅L-1 salt stress，P1 resists salt stress by promoting chlorophyll synthesis，increasing underground root biomass allcationand improving antioxidantcapacity.When thesalt stressisintensified，P1resistssaltstress by accumulating SSandPro，demonstrating moderate salttoleranceand potentialforcultivation inmildlysaline-alkali regions.

Keywords：Apple; salt stres; growth characteristics; physiological indexes;P1; dwarfing rootstock

平果（Malus domestica Borkh.），蔷微科平果属，为世界重要经济果树之一。（剩余15170字）