Identification and comprehensive evaluation of seedling salt tolerance of 300 barley germplasm resources

Objective This study aimed to screen barley germplasm resources with strong salt tolerance.

Methods Based on the salt damage index of six barley germplasm, 150 mmol/L was selected as the optimal NaCl concentration for assessing salt tolerance at the germination stage. Using this concentration, 300 barley germplasm of varying genotypes and regions were evaluated for seedling height, leaf length, root length, stem length, leaf width, stem thickness, and leaf area, and their salt tolerance indices were calculated. Salt tolerance was then comprehensively evaluated using principal component analysis, affiliation functions, and other analytical methods.

Results Under 150 mmol/L NaCl stress, the coefficients of variation for all measured barley traits exceeded 10%, except for leaf length, leaf width and stem diameter. Seven indicators were condensed into four principal components via principal component analysis, with a cumulative contribution rate of 83.342%. The D-value of each germplasm accession was calculated based on the weights of the four principal components, and the 300 germplasm resources were classified into four tolerance grades.

Conclusion Eleven salt-tolerant barley accessions were screened out.