目的 探究甘蔗10个优良新品系的抗旱性能，为抗旱品种选育及推广应用提供科学依据。方法 在人工干旱胁迫和正常供水处理下测定甘蔗伸长初期的根系活力，叶片脯氨酸、可溶性蛋白、可溶性糖、丙二醛（MDA）含量，叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性8项生理指标的变化；采用主成分分析与聚类分析方法综合评价甘蔗伸长初期的抗旱性。结果 受干旱胁迫后，甘蔗根系活力降低，叶片可溶性蛋白、可溶性糖、脯氨酸、MDA含量升高，叶片SOD、POD、CAT活性增强。聚类分析将包括对照品种ROC22在内的11个甘蔗品系分成抗旱性强、中度抗旱和抗旱性弱3类。抗旱性强的新品系为A6-13115和A3-1320，中度抗旱的新品系为A13-1396和A6-13122，抗旱性弱的新品系为A6-13111、A11-1390、A1-1305、A7-13120、A7-13104和A4-1316。结论 采用主成分和聚类分析方法对多个指标综合评价能提高甘蔗抗旱评价的可靠性、准确性。甘蔗新品系A6-13115和A3-13120抗旱性强。
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.