邓恩桉再生系统的研究

邓恩桉生长速度快、耐寒能力较强，近年来已成为中国南方地区的重要造林树种，但其种子主要依赖进口且价格昂贵，因此进行再生体系的研究对解决种苗问题具有重要意义。本研究以种子和腋芽为外植体建立了邓恩桉再生体系，研究结果如下：采用无菌播种后萌发产生的胚轴和子叶进行体细胞胚胎发生途径培养，诱导和分化的最佳培养基配方为1/2MS+6-BA0.5+NAA0.2+IBA0.5，芽继代培养周期25天，扩繁系数3.1；采用邓恩桉腋芽进行的器官发生途径培养，诱导和分化的最佳培养基配方为1/2MS+6-BA0.5+NAA0.2+IBA0.5，继代培养周期和扩繁系数与胚胎发生途径基本一致。将通过2种途径繁殖的芽苗转接到生根培养基1/2MS+NAA0.2+IBA0.5上，7天后陆续生根，25天后生根率70%~71%。试验结果为邓恩桉组培快繁及工厂化育苗提供了有力的理论和实践基础。

The study on tissue culture regeneration system of Eucalyptus dunnii

In recent years, the Eucalyptus dunnii had become an important afforestation tree species in southern China because of its fast growing and high cold-tolerance. But its seeds mainly depended on imports and the price is expensive, so to carry on the regeneration system of the research was of great significance to solve the problem of seedling. In this paper, a regeneration system of E. dunnii using seed and axillary bud as explants was established, the results showed: Using aseptic sowing technique of E. dunnii, cutting their hypocotyls and cotyledons and cultured in vitro, establishment of adventitious buds and plant regeneration of embryogenesis. The best culture medium was 1/2MS+6-BA0.5+NAA0.2+IBA0.5, the subculture cycle was 25 days, the subculture coefficiency reached 3.1. Furthermore, E. dunnii axillary buds were used to study organogenesis approach. The results showed that 1/2MS+6-BA0.5+NAA0.2+IBA0.5 medium also suitable for axillary buds induction and differentiation. Subculture cycle and propagation coefficient is consistent with the embryogenesis way. The axillary shoots were transferred to rooting medium 1/2MS+NAA0.2+IBA0.5 which come from embryogenesis and organogenesis pathway, 7 days later, successions generated roots, the rooting rate could reach to 70%-71% after 25 days. The results provided the theoretical and practical basis for the rapid propagation and factory production of E. dunnii.