title: Differentiation of the "Ascochyta complex" fungi of pea by biochemical and molecular markers.
abstract: Isolates of three closely related pea pathogens, Ascochyta pisi, Ascochyta pinodes (teleomorph Mycosphaerella pinodes) and Phoma medicaginis var. pinodella, were compared by means of isozyme analysis and restriction fragment length polymorphisms (RFLP) of amplified rDNA spacers. Three enzyme systems differentiated A. pisi from M. pinodes and P. m. pinodella. The internal transcribed spacers (ITSs) of the three fungi showed no intraspecific and very little interspecific variation after digestion with 12 endonucleases. Digestion of the intergenic spacer (IGS) with HinfI, and Sau3A revealed uniformity in A. pisi patterns which consistently differed from those of M. pinodes and P. m. pinodella. No clear distinction could be made between the latter two fungi which both showed intraspecific variability. Both biochemical and molecular markers thus discriminated between two Ascochyta species. The results also indicated a closer relationship between two organisms belonging to different genera (Ascochyta and Phoma) than between two species of the same genus (Ascochyta).
authors.affiliation: Station de Pathologie Végétale, Institut National de la Recherche Agronomique, Versailles, France.
authors.forename: S
authors.initials: S
authors.lastname: Faris-Mokaiesh
authors.forename: M
authors.initials: M
authors.lastname: Boccara
authors.forename: J B
authors.initials: JB
authors.lastname: Denis
authors.forename: A
authors.initials: A
authors.lastname: Derrien
authors.forename: D
authors.initials: D
authors.lastname: Spire
mesh_terms: D000429:Alcohol Oxidoreductases / Q000032:analysis / Q000235:genetics; D001483:Base Sequence; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry; D004275:DNA, Ribosomal / Q000737:chemistry*; D005956:Glucose-6-Phosphate Isomerase / Q000032:analysis / Q000235:genetics; D005954:Glucosephosphate Dehydrogenase / Q000032:analysis / Q000235:genetics; D007527:Isoenzymes / Q000032:analysis* / Q000235:genetics; D003904:Mitosporic Fungi / Q000145:classification* / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000382:microbiology*; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D007527:Isoenzymes; D000429:Alcohol Oxidoreductases; C022641:Shikimate dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005956:Glucose-6-Phosphate Isomerase