Breeding on Superior Clones of Betula alnoides

Super-seedlings were selected from 3-month-old seedlings of 14 superior individual half-sib progenies of Betula alnoides, and were cloned by tissue culture. Clonal test forests were built respectively in Shuangjiang County and Simao Distric, and the 8-year-old clonal test forest in Shuangjiang County and the 9-year-old in Pu'er District were measured and the genetic gain was analyzed. The results showed that there were significant differences in tree height and DBH among different clones in Shuangjiang County. The tree height of clone 1 and clone 4 was significantly different from that of the control, and the DBH of clone 1, clone 2 and clone 4 were significantly different from the control. Moreover, the tree height difference among different clones in Simao District was very significant, and the DBH of clone 1, clone 3 and clone 4 were significantly different from the control.The tree height and DBH of clonal test forest of B. alnoides in these 2 sites were comprehensively analyzed, and clones 1 and 4 of B. alnoides were selected, which were also called Lintui Superior Clone 1 and 4 of B. alnoides with excellent characters with fast-growing, high-yield, straight stem type, obvious apical advantage and good resistance.