Quantitative Analysis of Leaf Color of 10 Species of Rosaceae in Xinjiang

Leaf color, as a persistent and stable visual element in landscape design of garden plants, has increasingly demonstrated its esthetic and ecological value. Plants of the genus Rosa L. in the Rosaceae family exhibit rich species diversity and ornamental potential, yet systematic research on their leaf color characteristics and the physiological mechanisms underlying coloration remains relatively scarce. Using 10 wild rose species as materials, the L^*a^*b^* color model was employed to quantify leaf color parameters（L^* brightness, a^* red-green axis, b^* yellow-blue axis）, combined with chlorophyll content for correlation analysis, to elucidate the physiological basis of leaf color variations in Rosa species. The results revealed significant differences among species in L^*, a^*, and b^* values. Among them, Rosa alberti Regel. and Rosa laxa Retz. exhibited the highest brightness, while Rosa xanthina Lindl. showed the lowest. The a^* value indicated a greenish bias across all species, though greenness exhibited significant differentiation. The b^* value revealed distinct yellowish tendencies in some species. Through quantitative phenotyping of rose varieties, a ranking and grading system was established based on a comprehensive score（S）, with all varieties ranked from highest to lowest and categorized into three grades according to their rankings. Correlation analysis demonstrated a significant negative correlation between a^* and chlorophyll content, confirming the physiological role of chlorophyll in red light absorption. L^* values generally showed no significant correlation with chlorophyll, indicating that brightness is primarily influenced by physical properties such as leaf surface structure. The relationship between b^* and chlorophyll varied among species, reflecting the regulatory role of non-chlorophyll pigments. The research quantified the leaf color of the rose plant objectively, which provided the basis and reference for the evaluation and classification of rose germplasm resources and the color design of landscape.