position of Coniothyrium minitans

This paper is made available online in accordance with publisher policies. Please scroll down to view the document itself. Please refer to the repository record for this item and our policy information available from the repository home page for further information. To see the final version of this paper please visit the publisher's website. Access to the published version may require a subscription. Simple sequence repeat (SSR)–PCR amplification using a microsatellite primer (GACA) % and ribosomal RNA gene sequencing were used to examine the intraspecific diversity in the mycoparasite Coniothyrium minitans based on 48 strains, representing eight colony types, from 17 countries worldwide. Coniothyrium cerealis, C. fuckelii and C. sporulosum were used for interspecific comparison. The SSR–PCR technique revealed a relatively low level of polymorphism within C. minitans but did allow some differentiation between strains. While there was no relationship between SSR–PCR profiles and colony type, there was some limited correlation between these profiles and country of origin. Sequences of the ITS 1 and ITS 2 regions and the 5n8S gene of rRNA genes were identical in all twenty-four strains of C. minitans examined irrespective of colony type and origin. These results indicate that C. minitans is genetically not very variable despite phenotypic differences. ITS and 5n8S rRNA gene sequence analyses showed that C. minitans had similarities of 94 % with C. fuckelii and C. sporulosum (which were identical to each other) and only 64 % with C. cerealis. Database searches failed to show any similarity with the ITS 1 sequence for C. minitans although the 5n8S rRNA gene and ITS 2 sequences revealed an 87 % similarity with Aporospora terricola. The ITS sequence including the 5n8S rRNA gene sequence of Coniothyrium cerealis showed 91 % similarity to Phaeosphaeria microscopica. Phylogenetic analyses using database information suggest that C. minitans, C. sporulosum, C. fuckelii and A. terricola cluster in one clade, grouping with Helminthosporium species and ' Leptosphaeria ' bicolor. Coniothyrium cerealis grouped with Ampelomyces quisqualis and formed a major cluster with members of the Phaeosphaeriacae and Phaeosphaeria microscopica.