Lacourt Isabelle, Girlanda Mariangela, Perotto Silvia, Del Pero Massimiliano, Zuccon Dario, Luppi Anna Maria
Dipartimento di Biologia Vegetale, Viale Mattioli 25, 10125 Torino, Italy.
I. Lacourt and M. Girlanda contributed equally to this paper.
New Phytol. 2001 Mar;149(3):565-576. doi: 10.1046/j.1469-8137.2001.00058.x.
• Nuclear ribosomal sequence analysis was performed to investigate delimitation of common Oidiodendron species comprising endomycorrhizal symbionts and close associates of ectomycorrhizal plants. • Neighbour-joining, maximum likelihood and parsimony analyses were used to compare 35 ribosomal DNA (internal transcribed spacer (ITS) and 5.8S) sequences (including sequences available in databases) from 15 putative species. • Oidiodendron citrinum formed a monophyletic group nested within O. maius, whereas O. tenuissimum and O. griseum did not appear either as distinct groups or as a single complex. Pairwise nucleotide divergence values between O. citrinum and O. maius were very low and comparable to intraspecific values obtained for both species; values for O. griseum and O. tenuissimum, although higher, overlapped those observed at the intraspecific level for the two species. • Molecular data indicate that O. maius and O. citrinum, which were described as distinct, though related species, could be moved to a subspecific level; however, the delimitation of O. griseum and O. tenuissimum is still open to question. Taxonomic rank assignment to groups determined from sequence data analysis is discussed.
• 进行了核糖体序列分析，以研究构成内生菌根共生体和外生菌根植物紧密伴生菌的常见奥氏霉属物种的界定。• 采用邻接法、最大似然法和简约法分析，比较了来自15个假定物种的35个核糖体DNA（内部转录间隔区（ITS）和5.8S）序列（包括数据库中可用的序列）。• 柠檬色奥氏霉形成了一个嵌套在大孢奥氏霉内的单系类群，而纤细奥氏霉和灰色奥氏霉既未表现为不同的类群，也未表现为单一的复合体。柠檬色奥氏霉和大孢奥氏霉之间的成对核苷酸差异值非常低，与这两个物种的种内值相当；灰色奥氏霉和纤细奥氏霉的值虽然较高，但与这两个物种在种内水平观察到的值重叠。• 分子数据表明，被描述为不同但相关物种的大孢奥氏霉和柠檬色奥氏霉可以归为亚种水平；然而，灰色奥氏霉和纤细奥氏霉的界定仍存在疑问。讨论了根据序列数据分析确定的类群的分类等级归属。
