Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa.
Stud Mycol. 2006;55:289-98. doi: 10.3114/sim.55.1.289.
The genus Quambalaria consists of plant-pathogenic fungi causing disease on leaves and shoots of species of Eucalyptus and its close relative, Corymbia. The phylogenetic relationship of Quambalaria spp., previously classified in genera such as Sporothrix and Ramularia, has never been addressed. It has, however, been suggested that they belong to the basidiomycete orders Exobasidiales or Ustilaginales. The aim of this study was thus to consider the ordinal relationships of Q. eucalypti and Q. pitereka using ribosomal LSU sequences. Sequence data from the ITS nrDNA were used to determine the phylogenetic relationship of the two Quambalaria species together with Fugomyces (= Cerinosterus) cyanescens. In addition to sequence data, the ultrastructure of the septal pores of the species in question was compared. From the LSU sequence data it was concluded that Quambalaria spp. and F. cyanescens form a monophyletic clade in the Microstromatales, an order of the Ustilaginomycetes. Sequences from the ITS region confirmed that Q. pitereka and Q. eucalypti are distinct species. The ex-type isolate of F. cyanescens, together with another isolate from Eucalyptus in Australia, constitute a third species of Quambalaria, Q. cyanescens (de Hoog & G.A. de Vries) Z.W. de Beer, Begerow & R. Bauer comb. nov. Transmission electron-microscopic studies of the septal pores confirm that all three Quambalaria spp. have dolipores with swollen lips, which differ from other members of the Microstromatales (i.e. the Microstromataceae and Volvocisporiaceae) that have simple pores with more or less rounded pore lips. Based on their unique ultrastructural features and the monophyly of the three Quambalaria spp. in the Microstromatales, a new family, Quambalariaceae Z.W. de Beer, Begerow & R. Bauer fam. nov., is described.
该属由植物病原真菌引起，可导致叶和芽的疾病桉树及其近亲，科里姆比亚。Quambalaria spp.的系统发育关系，以前被分类在 sporothrix 和 ramularia 等属中，从未被涉及过。然而，有人认为它们属于担子菌目 exobasidiales 或 ustilaginales。因此，本研究的目的是利用核糖体 LSU 序列来考虑 Q. eucalypti 和 Q. pitereka 的目级关系。使用 ITS nrDNA 的序列数据来确定这两个 Quambalaria 物种与 Fugomyces（= Cerinosterus）cyanescens 的系统发育关系。除了序列数据外，还比较了所研究物种的隔膜孔的超微结构。从 LSU 序列数据得出的结论是，Quambalaria spp.和 F. cyanescens 形成了 Ustilaginomycetes 目 Microstromatales 的单系群。ITS 区的序列证实 Q. pitereka 和 Q. eucalypti 是不同的物种。F. cyanescens 的外模式分离株，以及来自澳大利亚桉树的另一个分离株，构成了第三个 Quambalaria 物种，Q. cyanescens（de Hoog & G.A. de Vries）Z.W. de Beer、Begerow & R. Bauer comb. nov. 隔膜孔的透射电子显微镜研究证实，所有三个 Quambalaria spp.都有带有肿胀唇的 dolipores，这与其他 Microstromatales 成员（即 Microstromataceae 和 Volvocisporiaceae）不同，后者具有具有或多或少圆形孔唇的简单孔。基于其独特的超微结构特征和在 Microstromatales 中三个 Quambalaria spp.的单系性，描述了一个新科，Quambalariaceae Z.W. de Beer、Begerow & R. Bauer fam. nov.。
