桉树抗冻性种质的筛选

Selections from Eucalyptus species of Freezing Resistance

云南常年冬天不冷,1982年度冬,一反常态,变成冬季奇寒,低温寡照的气候。不论是冷冬和冬雨,都出现了明显的极值。为了对比方便,将桉树(Eucalyptus)受冻后的生态反映情况分为五级,并以这个标准记录了在云南面积最大,分布最广的4种桉树的受冻情况,其中直干桉(E.maideni)、蓝桉(E.globulus)、大叶桉(E.robusta)、赤桉(E.camaldulensis)在玉溪海拔1680米处的平均受冻级别分别为1.00级,1.06级,1.39级,1.49级,此外还记录了57种按树受害情况。1983、1984到1988年度冬,我们测定了61种桉树的抗冻生理指标,这些室内测定数据,与室外桉树受冻的生态反映级别是基本趋于一致的。因此,根据测定数据,我们将61种桉树的抗冻性分为强、中、弱三等,可为云南桉树的合理布局提供科学依据。

Regularly,it is not cold in winter in Yunnan Province,but weather had been changed from its normal ehaviour intoa very cold,microthermal and sunless climate in the winter of1982.Extreme values had been appeared istinctly for both coldwinters and winter rains.For the sake of contrast,the ecological responses for thefrozen ucalyptus were divided into five grades and four speciesof Eucalyptus which have a greatest grown area and widepreaded distribution in Yunnan Province have been recordedaccording to this criterion among which the verage rozenrades of Eacalyptus grown in Yuxi area with an elevation of1680 meters such as .maideni.E.globulus,E.robusta nd E.camaldulensis were 1.00,1.06,1.39 and 1.49 respectively.Moreover,57 species of affected Eucalyptus have een ecoredealso.In the winters of 1983,1984 to 1988,we have measuredhe anti freezing physiological indices of 61 ecies f Eu-calyptus.These indoor-measured data are generally showing nodifference with the grades of ecological esponses for the out-door frozen Eucalyptus.Based on the measured data,we havedivided the freezing resistance or 1 species of Eucalyptusinto three grades,namely,strong,moderate and weak.It can beused as a scientificai basis for he rational distribution ofEucalyptus in Yunnan Provincs.