Effects of Mycorrhizal Inoculation and Exogenous Calcium on Drought Resistance of Acacia auriculaeformis
Using Acacia auriculiformis seedlings as experimental materials,the effects of exogenous calcium on mycorrhizal inoculation and the combined effects of mycorrhizal inoculation and exogenous calcium on seedling growth and physiology under drought stress were investigated through mycorrhi-zal inoculation and exogenous calcium application.The results showed that among the CaCl2 applica-tion rates ranging from 0 to 100 g/pot,the highest mycorrhizal infection rate(61.2％)was observed with 50 g/pot(45 mmol·L-1)of CaCl2.Compared to 75％soil water content,40％soil water con-tent resulted in decreased height and diameter growth increments of the seedlings,increased relative water deficit(RWD)in leaves,decreased chlorophyll content,net photosynthetic rate(Pn),water use efficiency(WUE),intercellular CO2 concentration(Ci),superoxide dismutase(SOD)activity,and soluble sugar content,and increased transpiration rate(Tr),stomatal conductance(Gs),and ma-londialdehyde(MDA)content,indicating significant drought stress damage.Under drought stress,both mycorrhizal inoculation and calcium application significantly improved the growth and physiologi-cal performance of the seedlings,with the combined treatment of mycorrhizal inoculation and exoge-nous calcium resulting in the greatest increase in height and diameter growth.Using 12 indicators in-cluding seedling height and ground diameter increments,RWD,chlorophyll content,Pn,Tr,WUE,Gs,Ci,MDA,SOD,and soluble sugar content as evaluation indices,a comprehensive evaluation of seedling drought resistance was conducted through principal component analysis.The results showed that seedlings treated solely with mycorrhizal inoculation had the strongest drought resistance,fol-lowed by those treated with a combination of mycorrhizal inoculation and exogenous calcium.The study suggests that exogenous calcium is beneficial for mycorrhizal inoculation in A.auriculiformis seedlings,and the drought resistance of mycorrhizal seedlings is significantly improved,but the a-mount of calcium application should be controlled within a moderate range.
Acacia auriculaeformismycorrhizacalciumdrought resistancegrowth and physiology
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维普
