title: Detection of rDNA ITS polymorphism in Rhizoctonia solani AG 2-1 isolates.
abstract: The sequence variability of the ribosomal internal transcribed spacer regions ITS1 and ITS2, including the 5.8S gene, was investigated for Rhizoctonia solani isolates of anastomosis group (AG) 2-1. During PCR RFLP analysis of eight isolates, the restriction patterns of four isolates showed an excess of bands after restriction with the enzymes AvaII and/or HincII, which suggested the presence of more than one ITS region. By cloning the ITS region of six isolates sequence heterogeneity was detected in the isolates that showed an excess of bands in the PCR RFLP analysis; up to nine different ITS regions were identified within one isolate. The same level of diversity was found within the same isolate as among isolates. In the phylogenetic tree based on the rDNA ITS sequences of several AG 2-1 isolates, sequences derived from the same isolate did not form distinct clusters, questioning the relevance of further subdivision of heterogeneous AG 2-1 isolates based on the ITS region.
authors.affiliation: Ghent University, Department of Crop Protection, Laboratory of Phytopathology, Coupure Links 653, B-9000 Ghent, Belgium.
authors.forename: Joke
authors.initials: J
authors.lastname: Pannecoucque
authors.forename: Monica
authors.initials: M
authors.lastname: Höfte
mesh_terms: D001483:Base Sequence; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D012232:Rhizoctonia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D021903:DNA, Ribosomal Spacer