Alleviating effects of silicon on sugarcane seedlings under aluminum stress

Aluminum（Al） toxicity is a practical problem in the acid soil area of Southern China，and is not easy to solve it for crops. In this paper，the effects of silicon on the growth and physiological indexes of sugarcane seedlings with different SiO32- treatments under Al3+ stress were studied by using the nutrient solution culture. Results showed that under the Al stress（ T1），compared with the normal（ CK），all of the plant height，dry weight，root length，root diameter，root volume and root surface area decreased significantly. Similarly，root activity，leaf SPAD value and superoxide dismutase（ SOD） decreased significantly. But the content of malondialdehyde（ MDA） and electrical conductivity increased significantly. It indicated that the normal growth and physiological activity of sugarcane plants were damaged under aluminum stress. While with a range of 1-2 mmol/L sodium silicate solution added to the nutrient solution，compared to T1，both the plant height and dry matter weight increased，root morphology parameters were significantly improved，and root activity and leaf SPAD value also increased significantly，yet MDA content and electric conductivity decreased significantly. It indicated that silicon could effectively relieve aluminum toxicity on sugarcane seedling.