利用RAPD标记进行桉树杂交亲本遗传变异的研究

RAPD Analysis on Genetic Variation in Parental Trees of Eucalyptus urophylla S. T. Blake and E. tereticornis Smith

利用RAPD分子标记技术分析了尾叶桉和细叶桉各lO个杂交亲本的遗传变异。结果表明,14 个随机引物共扩增产生143条谱带,其中在亲本间呈多态性的谱带88条(占61.5%),包括在两个种间呈多态性而在种内无多态性的谱带18条(占12.6%)。尾叶桉和细叶桉两个类群间遗传距离的平均值及其变幅分别为0.365和0.218-0.544;尾叶桉种内个体间遗传距离的平均值及其变幅分别为0.267和0.175-0.338,细叶桉种内个体间遗传距离的平均值及其变幅分别为0.258和0.119-0.378。利用亲本间的遗传距离进行聚类分析,20个亲本可以明显地分为尾叶桉组和细叶桉组,各组有其特征谱带,可以将尾叶桉和细叶桉识别开。试验结果为开展分子标记辅助的桉树杂交亲本选配和杂种子代表现预测奠定了基础。

Genetic variation of ten parental trees of each of Eucalyptus urophylla and E. tereticornis was investigated using Random Amplified Polymorphic DNA （RAPD） markers. Fourteen primers generated a total of 143 discernible and reproducible bands across the twenty parental trees analyzed, of which 88 （61.5%） were polymorphic, indicating a high level of genetic diversity among the parental trees tested. Of the total 143 bands amplified, 11 were present in all E. urophylla trees, and absent in all E. tereticornis trees, while seven were present in all E. tereticornis trees, and absent in all E. urophylla trees. The 18 species-specific fragments could be used as markers in the identification of species. The Nei＇s genetic distances between twenty parents were calculated. The range of genetic distance among trees of E. urophylla and E. tereticornis was 0. 175 -0. 338 with an average 0.267 and 0. 119 -0. 378 with an average 0.258, respectively, and that between E. urophlla and E. tereticornis was 0. 218 -0. 544 with an average 0.365. Cluster analysis was made basing on the genetic distances among parental trees, and the two species were separated exclusively in two groups. This work gives a preliminary exploration in marker-assisted grouping of parental trees and marker-assisted prediction of hybrid performance in eucalypt hybridization.