Physiological responses of new sugarcane lines to drought stress and evaluation of their drought resistances

Objective  To explore the drought resistances of 10 fine sugarcane lines and provide references for breeding, popularization and application of drought resistant cultivars.

Method  Changes of sugarcane root vitality, leaf proline and soluble protein and soluble sugar contents, leaf superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities at early elongation stage were measured under artificial drought stress and normal water supply treatments. Principal component analysis and cluster analysis were used to comprehensively evaluate the drought resistances of sugarcane lines at early elongation stage.

Result  Under drought stress, root activities of tested sugarcane lines decreased, while the contents of leaf soluble protein, soluble sugar, proline and malondialdehyde increased, as well as the activities of leaf SOD, POD and CAT . Cluster analysis divided 11 sugarcane lines including the control cultivar ROC22 into three categories, including strong drought resistance, moderate drought resistance and weak drought resistance. New sugarcane lines with strong drought resistance were A6-13115 and A3-1320, with moderate drought resistance were A13-1396 and A6-13122, with weak drought resistance were A6-13111, A11-1390, A1-1305, A7-13120, A7-13104 and A4-1316.

Conclusion  Using principal component analysis and cluster analysis, the comprehensive evaluation of multiple indicators, and can improve the reliability and accuracy of sugarcane drought resistance evaluation. New sugarcane lines A6-13115 and A3-1320 have strong drought resistance.