INTRASPECIFIC VARIATION IN SEED TRAITS OF ORMOSIA HENRYI PRAIN ACROSS SOUTHERN CHINA AND IMPLICATIONS FOR GERMPLASM CONSERVATION

Abstract

Ormosia henryi Prain is an endangered timber species with high ecological and economic value. Understanding its intraspecific variation is crucial for germplasm conservation and breeding. This study investigated seed trait variation among nine provenances across five provinces in southern China. Measured traits included seed length, width, thickness, and thousand-seed weight (TSW). Statistical analyses included ANOVA, correlation, principal component analysis (PCA), and cluster analysis. Results showed significant differences among provenances in all morphological traits (P < 0.01). TSW was strongly correlated with seed dimensions, especially thickness. Seed thickness was positively correlated with elevation, suggesting local adaptation. PCA, employed to reduce dimensionality and generate a composite score for ranking provenances, identified three principal components explaining 82.999% of total variance, with the Anshun (Guizhou) provenance exhibiting the highest comprehensive score. A PCA plot visually confirmed the separation of provenances based on seed traits and environmental factors. Cluster analysis grouped provenances into three clusters independent of geographic distribution, indicating genetic control over trait variation. These findings provide a basis for selecting superior germplasm for reforestation and conserving genetically diverse populations. The study highlights the importance of integrating phenotypic and environmental data in conservation planning for endangered tree species.