Journal of Anhui Agricultural Sciences

[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.