不同品种甜高粱苗期耐寒性分析研究

低温胁迫是影响甜高粱产量和品质的主要非生物因素之一，为更好地了解低温胁迫下苗期甜高粱耐低温的机制，并服务于甜高粱耐低温品种的选育，本研究以6 个甜高粱品种为材料，对其在低温胁迫及恢复处理后苗期叶片中的各项生理指标进行测定，并以各项指标的抗冻系数作为衡量抗冻性的指标，采用主成分分析法以及聚类分析对抗寒性做出综合评价。研究表明，低温胁迫后，6 个甜高粱品种Pro 含量均不同程度上升；而SOD、POD、CAT活性以及可溶性糖含量却呈现不同的变化趋势，部分品种表现为下降趋势。通过主成分分析以及聚类分析最终将6 个品种分为3 类，‘BJ0603’和‘EN-11’为强抗寒类型，‘EN-12’、‘IMP-2’和‘KFJT-1’为中度抗寒类型，‘BJ0602’为弱抗寒类型。本研究结果为甜高粱抗寒品种的选育提供了一定的理论依据。

Chilling Tolerance of Different Sweet Sorghum Varieties at Seedling Stage

Cold stress is one of the main abiotic factors which can affect the yield and quality of sweet sorghum. To better comprehend the resistant mechanism of sweet sorghum in seedling stage induced by cold stress, and screen the best chilling-tolerance varieties of sweet sorghum, six sweet sorghum varieties were used as materials in this study. The physiological indexes were detected in the leaf under cold stress and recovery treatment. And these indexes were used to evaluate the freezing resistance of sweet sorghum. The principal component analysis and cluster analysis were adopted to evaluate the overall chilling- tolerance of sweet sorghum. The results showed that the content of Pro increased in seedling leaves induced by cold stress.However, SOD, POD, CAT activity and the content of soluble sugar demonstrated different change trends in six sweet sorghum varieties, and the downtrend was also found in some varieties. At last, the six sweet sorghum varieties were divided into three groups based on the principal component analysis and cluster analysis, ‘BJ0603’and‘EN-11’were strong cold-resistant,‘EN-12’,‘IMP-2’and‘KFJT-1’were moderate coldresistant, and‘BJ0602’was weak cold-resistant. These results provide a foundation for screening cold tolerant varieties of sweet sorghum.