全国27个侧柏(Platycladus orientalis)地理种源,用Liu氏法计算标准遗传距离(Genetic dictances),根据Smcath和Sokal氏聚类原则,绘制了系统树(ptylo genetic tree)。聚类结果表明:参试的27个侧柏种源可聚力4个明显的类群;同一类群内种源间遗传距离小,不同类群间遗传距离大。就选择遗传距离相距较远,综合性状好,主成分能够互补的种源,建立改良的种源采种林分或种子园,可望获得增益等问题进行了探讨。 The geographical provenance of 27 Platycladus orientalis in the whole country was calculated using the Liu’s method for genetic dictances and the ptylo genetic tree was drawn according to the Smcath and Sokal clustering principles. The clustering results showed that there were four distinct taxa in 27 endemic species of Arborvitae. The genetic distances among provenances in the same species were small and the genetic distances among different taxa were large. The problems such as the selection of improved provenances for planting seed orchard and gaining gain are discussed in this paper.