Drought tolerance evaluation of Fraxinus mandshurica in a semi-arid area.

BACKGROUND

Rupr. is a key forest species in Northeast Asia, primarily distributed in semi-humid regions. Given its wide range of provenances, exhibits substantial genetic and phenotypic variations. To identify drought–tolerant lines, we evaluated physiological, biochemical, and growth traits of two-year-old seedlings grown in a semi-arid environment across spring, summar and autumn.

RESULTS

Principal component analysis (PCA) of 24 trait variables yielded 10 principal components per season, accounting for approximately 85% of the cumulative variation. We developed a comprehensive drought evaluation metric ( value) for each line by calculating weighted averages of PCA scores. Cluster analysis base on seasonal values categorized 69 lines into three groups: drought-tolerant, weak drought-sensitive, and drought-sensitive. Using two growth traits, these lines were further classified into high-, medium-, and low-growth groups. From this, we identified five elite lines combining drought tolerance and rapid growth. Stepwise regression revealed that employs distinct drought-tolerance strategies across seasons.

CONCLUSIONS

We developled robust drought-tolerance evaluation models for and selected five high-performing lines with dual traits of drought tolerance and fast growth. Our results provided a basis for afforestation efforts of in semi-arid regions.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s12870-025-07146-w.