Development of DUS Test Guidelines for new varieties of Viburnum L.

Distinctness, uniformity and stability (DUS) Test Guidelines for new varieties of Viburnum L. were developed according to the principles and requirements of the International Union for the Protection of New Varieties of Plants (UPOV) and China. The development processes, including selection and determination of testing characteristics, determination of expression states of characteristics, selection of example varieties, determination of the order of characteristics, and assessment of distinctness, uniformity and stability, are described in this paper. There were 54 testing characteristics: 24 qualitative characteristics (QL), 15 quantitative characteristics (QN), 15 pseudo-qualitative characteristics (PQ) and 34 example varieties in the DUS Test Guidelines. Among the 54 testing characteristics, 20 were asterisked and 34 were non-asterisked. Seven were selected for variety groupings and 18 were adopted in the Technical Questionnaire. The development of these DUS Test Guidelines will be useful for the application and protection of new Viburnum varieties. The Guidelines will provide technical support for DUS testing of Viburnum and serve as a reference for the development of new varieties in other countries.