Effects of aluminum stress on physiological indies of cowpea seedlings root

The cowpea cultivar T6(Aluminum-tolerant) and S3(Aluminum-sensitive) were selected as materials to study the effects of different concentrations of aluminum on the root growth and physiological characters of cowpea seedlings.The results showed that the root lengths of T6 and S3 were inhibited with the increase of aluminum(Al) concentration,and the inhibition to S3 was greater than that to T6.The MDA contents in T6 and S3 roots were significantly increased with the increase of Al concentrations,and S3 was increased more than T6.The activities of SOD,POD and CAT in T6 and S3 roots rose with the rising of aluminum concentrations,the SOD activity in S3 root being increased more than that in T6 root and the activities of POD and CAT in T6 root being increased more than that in S3 root.After exposure to Al,both malic aid and citric acid were secreted from T6 and S3 roots,and the malic acid content secreted from T6 root was higher than that from S3 root.