安徽农业科学

[目的]探究不同高粱品种在萌发阶段对盐胁迫的响应机制，筛选耐盐性优异的种质资源，为盐碱地高粱高产栽培及耐盐品种选育提供理论依据与材料支撑。[方法]以10份高粱品种为试验材料，采用150 mmol/L NaCl溶液模拟盐胁迫环境，以去离子水为对照，测定发芽势、发芽率、发芽指数、活力指数、根冠比、单株芽鲜重、单株根鲜重等11项指标。计算各指标相对值后，通过相关性分析、主成分分析及隶属函数法进行综合评价，并结合聚类分析划分耐盐等级。[结果]盐胁迫对高粱萌发期各指标均产生显著影响，除单株根干重外，其余10项指标在处理间差异极显著(P<0.01);活力指数变幅最大(-75.2%),单株根干重变幅较小(26.1%)。相关性分析表明，多数指标间呈显著正相关，其中发芽势与发芽率相关系数较高(0.904),活力指数与单株芽长相关系数达0.956。主成分分析提取3个综合因子，累计贡献率达88.589%,确定发芽率与活力指数为核心评价指标。基于综合评价值(D值)聚类分析，将10份材料划分为高度耐盐型、耐盐型、中度耐盐型和盐敏感型4类，其中品种8(D=0.94)耐盐性最强，品种20(D=0.05)耐盐性最弱。[结论]供试高粱品种萌发期耐盐性存在显著基因型差异，筛选出的高度耐盐品种可为盐碱地高粱种植及遗传改良提供优质亲本材料。

[Objective]To explore the response mechanisms of different sorghum cultivars to salt stress during the germination stage,screen germplasm resources with excellent salt tolerance,and provide theoretical basis and material support for high-yield cultivation of sorghum in saline-alkali soils and breeding of salt-tolerant cultivars.[Method]10 sorghum cultivars were used as experimental materials.A 150 mmol/L NaCl solution was used to simulate the salt stress environment,with deionized water as the control.11 indicators were determined,such as germination potential,germination rate,germination index,vigor index,root-shoot ratio,fresh weight of sprout per plant,and dry weight of root per plant.After calculating the relative values of each indicator,comprehensive evaluation was performed through correlation analysis,principal component analysis,and membership function method,and salt tolerance grades were classified by cluster analysis.[Result]Salt stress had a significant impact on all indicators of sorghum during the germination stage.Except for the dry weight of individual roots,the other 10 indicators showed extremely significant differences among the treatments(P<0.01).The vigor index had the largest variation range(-75.2%),while the dry weight of individual roots had a relatively small variation range(26.1%).Correlation analysis showed that most indicators were significantly positively correlated;the correlation coefficient between germination potential and germination rate was higher(0.904),and the correlation coefficient between vigor index and individual shoot length reached 0.956.Principal component analysis extracted 3 comprehensive factors with a cumulative contribution rate of 88.589%,identifying germination rate and vigor index as the core evaluation indicators.Based on cluster analysis of comprehensive evaluation values(D values),the 10 materials were divided into 4 categories:highly salt-tolerant,salt-tolerant,moderately salt-tolerant,and salt-sensitive.Among them,cultivar 8(D=0.94) had the strongest salt tolerance,and cultivar 20(D=0.05) had the weakest.[Conclusion]There are significant genotypic differences in salt tolerance among the tested sorghum germplasms during the germination stage.The screened highly salt-tolerant cultivars can provide high-quality parental materials for sorghum cultivation in saline-alkali soils and genetic improvement.