Abstract:In order to evaluate salt tolerance in sunflower germplasm resources and identify elite accessions, the salt tolerance of 444 sunflower germplasm resources was evaluated under 250 mmol/L NaCl stress at germination and seedling stage, and also assessed under saline-alkali soil condition at the whole growth period.The salt tolerance analysis and evaluation was performed by observing a number of traits including the relative values(ratio of each indicator compared to the control treatment)of germination rate at germination stage,six indexes at seedling stage (survival rate,leaf area,plant height,SPAD value,etc.)and seven indexes at the whole growth period(plant height,sunflower diameter,seed setting rate,yield related traits,etc.) The correlation analysis results indicate that there was a highly significant positive correlation between each two indexes at seedling stage, with correlation coefficients ranging from 0.518-0.790. The correlation between most of the seven indicators in the whole growth period reached a significant or extremely significant level. The analysis of principal component, membership function value, cluster and comprehensive salt tolerance evaluation were performed based on these relative indicator values, then 132 salt resistant materials at germination stage, 9 at seedling stage, and 41 at whole growth stage were identified. Six germplasm resources (ZX0365, ZX0389, ZX1391, ZX1394, ZX3089, ZX3094), which showed salt tolerance in the three periods, can be utilized for subsequent salt-tolerant gene mining and breeding. Correlation analysis of salt tolerance levels for 124 accessions at three stages (germination, seedling, and the whole growth period) indicated a highly significant correlation among the salt tolerance assessments at each stage. The salt tolerance assessments of the germination and seedling stages can provide effective references for selecting salt-tolerant materials when planting sunflower in saline-alkali soil.This study provided method and material basis for the selection of salt-tolerant sunflower varieties.