脱落酸对NaCl胁迫下马蔺幼苗生长、叶片气孔特征和光合性能的影响OA

[Objective]The effects of abscisic acid(ABA)on the growth,leaf stomatal characteristics,and photosynthesis of Iris lactea seedlings under severe salt stress were studied.We aim to screen the app-ropriate ABA concentration to enhance salt tolerance of I.lactea,and to provide a basis for the cultivation of I.lactea that is tolerant to severe saline stress.[Method]Using'ML04'and'ML35'I.lactea seed-lings as materials,the growth,stomatal traits,chlorophyll content,gas exchange parameters and other in-dices under NaCl stress after spraying ABA(0,1.0,2.5,5.0,10 μmol/L)were analyzed.[Result]Under NaCl stress,both I.lactea seedlings showed salt damage symptoms,and the leaf damage of'ML35'was more severe than'ML04'.Spraying of ABA(1.0-10 μmol/L)increased salt tolerance of the two I.lac-tea seedlings,and'ML04'was increased more than'ML35'.ABA increased the plant height and biomass by adjusting the stomatal morphology and spatial distribution pattern to optimize the gas exchange process,reducing the decrease of chlorophyll content,and enhancing its net photosynthetic rate,stomatal conductance,transpiration rate,intercellular CO2 concentration and water use efficiency,thereby improving salt tolerance in I.lactea seedlings.[Conclusion]Spraying ABA could alleviate the growth of I.lactea seedlings under salt stress,and 2.5 μmol/L ABA had the best effect.