Research on digital analysis technology of leaf color in tea (Camellia sinensis (L.) O. Kuntze)

Accurate classification of leaf color phenotypes is fundamental to the characterization and utilization of tea (Camellia sinensis (L.) O. Kuntze) germplasm resources. To establish a rapid and objective approach for identifying and categorizing the leaf color of tea shoots, an integrated leaf color determination device was developed. This device combines a high-resolution scanner, a leaf color recognition module, and an RGB color analysis unit to capture precise color information from tea shoots. The acquired data were converted into CIELab color parameters and validated using a standard color difference meter. Although minor discrepancies were observed between the chromatic values obtained from the device and those measured by the colorimeter, both exhibited consistent trends and strong correlations, accurately representing the true leaf coloration. The device enabled quantitative evaluation of young shoot color, allowing categorization into six distinct groups: light green, green, purple-green, green-purple, red-purple, and dark-purple. Seasonal variation patterns in leaf color across spring, summer, and autumn were also characterized. This study establishes a novel method for the digital analysis of leaf color, offering a reliable framework for germplasm evaluation, phenotypic classification, and tea breeding research.