The Relationships Between Branching Characteristics and Its Performance of Current-year Branches of Taxus yunnanensis

To reveal the influence of branching characteristics on biomass traits and overall performance of Taxus yunnanensis current-year branch, and clarify the current-year branch branching characteristics regulation technology in pharmaceutical raw material forest. The overall performance of T. yunnanensis current-year branch were evaluated by using principal component analysis method. The relationships between current-year branch branching characteristics such as main branches branch diameter, main branches branch length, branch diameter and branch length, branch number of the first-order branches, and current-year branch biomass traits such as leaf biomass, total biomass, leaf biomass ratio and overall performance were researched by path analysis, the key points and directions of current-year branch branching characteristics regulation were clarified and verified. The results showed that there were abundant variations in those branching characteristics and biomass characters of T. yunnanensis current-year branches. The branch number and branch length of the first-order branches had a very significant positive effect on leaf biomass, total biomass and leaf biomass ratio of T. yunnanensis current-year branches; the main branches branch diameter had a significant positive effect on leaf biomas and total biomass of T. yunnanensis current-year branches. The main branches branch length had a significant negative effect on leaf biomass ratio of T. yunnanensis current-year branches; the relative importance order and the dominant branching characteristic factors of branching characteristic on biomass traits of current-year branches changed. The key points and directions of current-year branches branch characteristics regulation for promoting leaf biomass and total biomass, increasing leaf biomass ratio of current-year branch were different. The branch number, branch length of the first-order branches and main branches branch diameter had a significant positive effect on the overall performance of current-year branch, while the effects of main branches branch length and branch diameter of the first-order branches on the overall performance were no significant. The ideal branching characteristics of T. yunnanensis current-year branch in pharmaceutical raw material forest was wider branch number of the first-order branches for the first time, followed by longer branch length of the first-order branches, finally larger branch diameter of the main branches. The key points and directions of current-year branch branch characteristics regulation of T. yunnanensis in pharmaceutical raw material forest was to promote the first-order branches number.