Effects of the exogenous organic acids on rape root exudates characteristics under aluminum stress

Aluminum(Al) toxicity is the most important factor limiting plant growth and development on acid soil(pH 5.5).Hydroponic experiments were used to investigate the effects of exogenous organic acids on root exudation of two rape genotypes,Heza No.7(Al-tolerant) and Zhongnongyou No.6(Al-sensitive),under the condition of Al stress.The result showed that exogenous organic acid(citrate and malate) had good mitigation affect for rape,especially for Zhongnongyou No.6,but its didn't completely mitigate the aluminum toxicity.Comprehensive analyzing evaluation by the method of subjection function showed that malic acid had the best mitigation effects for root exudation,and citrate and malate had the better effect for root exudation.