采用髓心形成层对接法对马占相思及其杂种优树开展嫁接研究, 结果表明: 优树的基因型对于嫁接结果具有显著影响, 杂种无性系平均嫁接成活率达 82 %, 高出纯种无性系 2倍; 嫁接季节对接活率有很大影响, 春季接活率为 76.9%～82.0 %, 分别比夏季、秋季提高 130 %、190 %以上, 冬季嫁接成活率很低; 砧木地径以 0.5～0.8cm为佳, 接口高度 30～4 0 cm为优, 接穗以具有 4～5个腋芽的穗段为优。

以聚乙二醇(PEG-6000)的渗透溶液模拟水分胁迫条件,比较了不同水分胁迫强度下3种相思幼苗的抗旱性, 并确定了鉴定幼苗抗旱性的生理指标。结果表明:相对电导率、相对含水量、相对水分亏缺、可溶性糖含量、游离脯 氨酸等指标可作为鉴定相思幼苗早期抗旱性的生理指标;3个树种的抗旱能力排序为:厚荚相思大叶相思马占相思。

Effects of substrates, type of auxin, treatment concentration and time on rooting ability of Acacia mangium were systematically studied, and the change trend of rooting ability over time were analyzed. The results obtained from the experiment indicated that the substrate of yellow subsoil could improve the rooting rate of the cuttings significantly. IBA was superior to other auxins in increase the number of mean roots and the longest root length. And general rooting effect for different treatments was evaluated based on subordinate function values analysis. The optimized combinations were the cutting treated by IBA 400 mg·L-1 soaked for 2 hours. Callus were occurred in 5 d after cutting, and higher rooting period occurred in 10—15 d and 25—30 d after cutting.

Taking Acacia mangium elite trees as explants, the tissue culture technique system for dormant bud of 3-5 year-old elite trees was established. The system includes the germination-inducing of the dormant buds, the multiplying of shoots, the rooting of adventitious shoots, and the pre-treating and transplanting of seedlings. The medium MS + Sucrose 30 g·L-1 + BA 0.5 mg·L-1 + NAA 0.1 mg·L-1 was used for inducing the dormant buds; the medium MS + BA 1.0 mg·L-1 + NAA 0.05 mg·L-1 was used for multiplying; while the medium 1/2 MS + IBA 2.0 mg·L-1 + NAA 0.5 mg·L-1 was used for rooting. The results revealed that it was viable to producing field seedlings with micropropagation. Although the branches with dormant buds harbored many kinds of microbes and the adventitious shoots were not easy to root, 20% to 30% healthy germination could be yielded and the rooting rate of adventitious shoots could be higher than 85%. Pretreated with ABT powder (rooting hormone), both the rooting rate and survival rate of adventitious shoots were nearly 100%.

采用电导法对南亚热带的马占相思、大叶相思、厚荚相思的幼苗在树种和种源2个层次上的耐寒性进行了评估,并进行了排序。结果表明:在树种和种源层次上, 3种相思耐寒性变异均达极显著差异;马占相思的低温敏感区为6 ℃,大叶相思和厚荚相思的低温敏感区为0～3 ℃;最耐寒的马占相思种源是17703,大叶相思种源是19244,厚荚相思种源是17562和16598。

The effects of applying N(urea, 46% N), P(phosphate, 12% P2O5) and K(potassium sulphate, 54% K2O) fertilizers on the growth performance and biomass yield of 8-month-old Archidendron clypearia seedlings were examined by L9 orthogonal array with 3 replicates in the nursery of Zengcheng Forest Farm of Guangzhou, Guangdong Province. The test seedlings were potted with the subsoil of total N 0.0484%, total P 0.1518% and total K 1.2629%, and fertilized at the 2nd and 6th months with the application rates of 0, 10 and 20 mg of N, 0, 20 and 50 mg of P and 0, 10 and 20 mg of K per seedling. The results showed that the diameter at ground level(DGL), the height and the oven-dried weight biomass of 8-month-old seedlings differed significantly at P=0.05. The combined application dose of 20 mg N, 20 mg P and 0 mg K per seedling resulted in the best seedling growth and biomass yield. N fertilizer was a significant factor in the growth of DGL and height of A. clypearia seedlings. P fertilizer had no significant effects on both DGL and height, while K fertilizer only affected DGL significantly. Analysis of the leaf and root stoichiometry suggested that N may be the most single limiting nutrient, A. clypearia seedlings used N more efficiently than they used P.