前言每一个完整的育种计划都包括人工杂交授粉。人工控制授粉可以获得自然界中永远不可能出现的优良组合,这就是人工杂交的目的。林业实践已经证明:新的优良遗传组合可以达到林木速生、丰产和优质的目的,并能增加树木对不良环境条件的适应性和抗病虫害能力。目前世界上在桉树人工控制杂交育种方面已取得了巨大成功。如巴西的巨桉(Eucaly-ptus grandis)×尾叶桉(E.urophylla),美国佛罗里达的巨桉×大叶桉(E.robusta) Preface Every complete breeding program includes artificial crossbreeding. Artificially controlled pollination can get an excellent combination that can never happen in nature, which is why artificial crosses are made. Forestry practice has proven that the new good genetic combination can achieve the purpose of quick-growing trees, high yield and high quality, and can increase the adaptability of trees to adverse environmental conditions and the ability to resist diseases and pests. The world has achieved great success in artificially controlling hybridization and breeding of eucalyptus. Such as Eucalyptus grandis × E.urophylla in Brazil, E. grandis in Florida, USA × E. robusta,