Abstract:

In order to explore the salt tolerance of different sorghum varieties at seedling stage， and screen salt tolerant variety to improve and develop saline soil，19 sorghum varieties were used as materials， and 4 salinity gradients including 0（CK）、100（S1）、150（S2）、200 mmol·L^-1 NaCl（S3） were set up to determine germination index and 11 parameters of aboveground and belowground at the germination and seedling stage. The data was analyzed by the analysis of variance， correlation analysis， principal component analysis， affiliation function analysis and cluster analysis to evaluate the salt tolerance of sorghum seedlings. The results showed that the evaluated parameters were significantly affected under salt stress， and the parameters were decreased gradually with salt level increased. Among the treatments， the maximum decreased was showed under S3 treatment. Compared with CK the plant height was decreased by 79.60%， stem diameter by 44.6%， fresh weight of aboveground by 89.97%， dry weigh of aboveground by 62.30%， total root length by 95.65%， root total surface area by 94.56% and root volume of sorghum by 91.97% under S3 treatment. The evaluated 19 sorghum varieties were classified into 4 groups according to the comprehensive salt tolerance coefficient， salt tolerance measure and hierarchical cluster analysis， of which 5 varieties were classified in strong salt tolerance group， another 5 in middle salt tolerance group， 7 varieties in weak salt tolerance group， and 3 varieties in salt sensitive group. Principal component analysis showed that the 3 principal components could represent 78.50% of the original 11 indicators， and root total surface area， dry weight of aboveground and fresh weight of underground could be used as the main indicators in evaluating salt tolerance of sorghum seedlings. The highlight was built a comprehensive salt tolerance evaluation method by integrating aboveground phenotypes and underground root system， which could provide theoretical support for the screening and breeding of salt-tolerant crops.

Key words: salt tolerance, Sorghum, variety screening, comprehensive salt tolerance coefficient

摘要：

为探究不同高粱品种苗期的耐盐性，为开发和利用盐碱地筛选耐盐品种，以19份高粱品种为试验材料，设置0（CK）、100（S1）、150（S2）、200 mmol·L^-1 NaCl（S3）共4个盐处理，在萌发期和苗期对萌发指标和地上与地下部11个表型指标进行统计，通过差异性分析、相关性分析、主成分分析、隶属函数分析和聚类分析方法，评价高粱苗期耐盐性。结果表明，盐胁迫显著影响高粱萌发和生长相关指标，各指标均随盐梯度的增加逐渐降低。其中，在S3水平下降幅最大，与CK相比，各品种平均株高降低79.60%，茎粗降低44.60%，地上部鲜重降低89.97%、地上部干重降低62.30%、总根长降低95.65%、根系总表面积降低94.56%，根系体积降低91.97%。在此水平下，通过综合耐盐系数、耐盐性度量值和系统聚类分析将19份高粱品种划分为4个级别，其中，强耐盐级别包括5个品种，较强耐盐级别包括5个品种，弱耐盐级别包括7个品种，盐敏感级别包括2个品种。主成分分析表明，3个主成分可以代表原11个指标78.50%的数据量，其中根总表面积、地上部干重和地下部鲜重可以作为高粱苗期耐盐的主要评价指标。通过整合地上部表型与地下部根系形态指标构建了高粱综合耐盐评价方法，结果可为耐盐高粱选育提供理论支撑。

关键词: 耐盐性, 高粱, 品种筛选, 综合耐盐系数