巨桉遗传改良研究进展

Advances in Research on Genetic lmprovementof Eucalyptus grandis

进行巨桉种源试验和地理变异研究时，应重视从树种的生物学特性出发，考虑试材的取样标准、群体的生殖和生态特性，采用现代生物气候方法综合分析。巨桉有些群体存在着复杂的多型性，采用复合轮回选择能明显提高自由授粉家系后代的遗传增益，并提高种子园改良的质量。应用入选家系或个体的无性繁殖材料进行改良，可获得更大的遗传增益。巨桉遗传改良应把有性和无性两条途径结合起来，遵循简便、实用和高效的原则；基于这个原则，本文提出了巨桉目前可能的最佳改良程序。

Abstract Eucalyptus grandis Hill ex Maiden, one of the most fast-growing and mostwidely planted eucalyptus in the world, introduced into many tropical and subtropicalcountries and made progress in genetic improvement. The geographic variation andprovenance studies are the basis of genetic improvement for E. grandis. More emphasisshould be given to population reproductive and ecological habits in the research on ge-ographic variation and provenance triales of the species. Biologyclimate analysis is abetter way for studying provenance variation and ecocline of the species. Some populations of the species present the mixed ploymorphology and hence the higher genetic gainin advanced generation breeding can be achieved by recurrent selection system and giverise to additional genetic gain in operational seed orchard by using the clonal materialsfrom selected families and individuals. A probably optimum improvement program is developed in terms of fast, sirnple and effective tree improvement principle.