前言:热带桉树育种系统是多样化的,花期的选择和其它因子是有利于自花传粉的,特别在一个树种内,几乎所有单项试验都表明,某种程度上是自交能孕的。桉树近亲繁殖和异型杂交两者表现都很普遍。因此,一般轻易地判断说,桉树异型杂交可能有效,并决定采取像松树人工林遗传改良的育种战略,那是没有充分根据的。在桉树育种系统和群体内的选择结果 Foreword: Tropical Eucalyptus breeding systems are diverse, with flowering options and other factors favoring self-pollination, and in almost any single species, almost all single trials have shown to some extent self-fertile. Eucalyptus both inbreeding and crossbred performance are common. Therefore, it is generally not easy to judge that the eucalyptus heterosexual hybridization may be effective and decided to adopt a breeding strategy like the genetic improvement of pine plantations, which is not well founded. Selection results in eucalyptus breeding systems and populations