[Development of DUS testing guidelines of Angelica dahurica varieties]

To explore the distinctness, uniformity, and stability(DUS) testing technology for Angelica dahurica and develop its DUS testing guidelines, this study conducted systematic research on the morphological and growth characteristics of A. dahurica throughout its whole growth period. The research was based on 428 A. dahurica lines from 48 sampling sites across China, with unified standardized field planting, regular and fixed-point observation, classified statistics of phenotypic characteristics, and comprehensive data analysis. Ultimately, 49 test characteristics were identified, including 36 basic characteristics and 13 optional characteristics. Classified by attribute, they consisted of 4 qualitative characteristics, 3 pseudo-qualitative characteristics, and 42 quantitative characteristics. Classified by organ and growth stage, the characteristics covered 2 cotyledon characteristics, 19 leaf characteristics(including basal leaves and cauline leaves), 2 plant characteristics, 3 saccate leaf sheath characteristics, 5 fruit characteristics, 9 root characteristics, 5 stem characteristics, 3 flower characteristics, and 1 growth period characteristic. Through the evaluation of characteristic discriminability and stability, five grouping characteristics were screened out, namely "basal leaf: anthocyanin coloration on the back of the leaf sheath" "basal leaf: anthocyanin coloration at the attachment site of the petiolule" "flowering period" "plant: height" "main root: arrangement pattern of lenticel-like protuberances". These can serve as important bases for the preliminary screening and classification of A. dahurica varieties. Meanwhile, 20 standard varieties with typical phenotypes were identified to provide a unified reference for characteristic observation. In addition, the guidelines also specify the scope of application, requirements for propagation materials, growth stages, observation periods, observation methods, DUS judgment criteria, and other content. This study fills the gap in the field of DUS testing technology for A. dahurica, and provides a scientific basis and technical support for DUS testing, resource identification and description, variety breeding of A. dahurica varieties, as well as management and protection of new A. dahurica arieties.