Drought resistance strategy of Camellia weiningensis, an endemic species in southwest China, based on leaf traits

To investigate the drought resistance of Camellia weiningensis , a unique wild woody oil-bearing species from the high-altitude regions of Guizhou, and provide a theoretical foundation for breeding drought-resistant varieties, this study utilized 42 leaf samples of C. weiningensis . The research addressed the existing gap in knowledge regarding the species' drought resistance by employing a range of methodologies to assess 22 indicators related to leaf phenotype, anatomy, and physiology. Principal component analysis (PCA) and cluster analysis were performed to comprehensively evaluate the drought resistance of C. weiningensis and identify superior drought-resistant strains. Cluster analysis categorized the 42 C. weiningensis germplasms into three groups: 27, 9, and 6 germplasms, respectively. PCA extracted six principal components, accounting for a cumulative contribution of 74.182%. Based on comprehensive evaluation through cluster and principal component analyses, the top 10 drought-resistant strains of C. weiningensis were ranked as follows: WN25 > WN28 > WN36 > WN21 > WN42 > WN35 > WN32 > WN08 > WN23 > WN30. The drought-resistant C. weiningensis germplasms from high-altitude Guizhou exhibit exceptional performance in phenotypic traits, moisture content, vein thickness, palisade tissue thickness, POD activity, and total chlorophyll content, positioning them as valuable candidates for future breeding efforts.