蓝桉、直干桉优树选择研究

蓝桉(Eucalyptus globulus Labill)和直干桉(E.maidenii F.V.M.)在云南引种时间长,生长快,经济价值高,适应性强,省内绝大部分地区都有栽培,现已成为最重要的速生丰产林造林树种。栽培地区正迅速向低山、缓坡地带扩展,造林面积以每年十多万亩的速度激增。省内计划大面积营造以这两个树种为主的纸浆林,选育良种成了当前生产中的紧迫任务。这两个树种原产澳大利亚、世界各地已广泛引种。但蓝桉以西班牙和葡萄牙种植最多,他们在选优建园和培育新品种方面都取得了成就。国内以四川省林科所在西昌地区进行蓝桉选优为最早,并提出了优树年生量的绝对指标。直干桉全球很多地方都有引种,但尚未见到国内外对它进行遗传改良的报道。

A STUDY ON PLUS TREE SELECTION IN EUCALYPTUS GLOBULUS LABILL AND E.MAIDENII F.V.M.

The trees were selected in three aspects: Qualitative characters, quantitative characters and resistance. But we paid much attention to quantitative characters evaluated by standard selection differential. The quantitative characters and resistance were assessed with independent criteria.Four most important factors have been found out by means of double selection stepwise regression from eighteen variables which include the characters of plus trees and the sampling statistics. Eleven characters of plus trees were divided into five groups and the plus trees were separated into four parts by principal component analysis(PCA).According to the results obtained from these analysis, it was shown that quantitative characters were more accurate and to be used easily by standard selection differential of the tree heights. And four criteria have been proposed to estimate plus trees.