title: Morphological, ontogenetic and molecular characterization of Scutellospora reticulata (Glomeromycota).
abstract: The arbuscular mycorrhizal (AM) fungus Scutellospora reticulata (CNPAB11) was characterized using morphological, ontogenetic and molecular approaches. Spore ontogenesis was studied using Ri T-DNA transformed carrot roots and observations were compared with those published for eight other, pot-cultured, Scutellospora species. The sporogenesis of S. reticulata exhibited an unreported pattern of outer spore wall differentiation. In addition, Denaturing Gradient Gel Electrophoresis (DGGE), targeting the V9 region of the SSU nrDNA, was used to differentiate S. reticulata from 16 other Scutellospora species and results were confirmed by sequencing analysis. Phylogenetic analyses, using nearly full length SSU nrDNA sequences, grouped S. reticulata in a cluster together with S. cerradensis and S. heterogama, species that share similar spore wall organization and also possess ornamented external walls. PCR-DGGE and sequence analysis revealed intragenomic SSU nrDNA polymorphisms in four out of six Scutellospora species tested, and demonstrated that SSU nrDNA intragenomic polymorphism could be used as a marker to differentiate several closely related Scutellospora species.
authors.affiliation: Empresa Brasileira de Pesquisa Agropecuária, Embrapa Agrobiologia (CNPAB), Caixa Postal 74505, CEP 23851-970, Rodovia BR 465-RJ, km 7, Seropédica, Rio de Janeiro State, Brazil. fdesouza@cnpab.embrapa.br
authors.forename: Francisco Adriano
authors.initials: FA
authors.lastname: De Souza
authors.forename: Stéphane
authors.initials: S
authors.lastname: Declerck
authors.forename: Eric
authors.initials: E
authors.lastname: Smit
authors.forename: George A
authors.initials: GA
authors.lastname: Kowalchuk
mesh_terms: D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005819:Genetic Markers; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000145:classification / Q000166:cytology / Q000502:physiology; D010802:Phylogeny; D011110:Polymorphism, Genetic; D016415:Sequence Alignment; D017421:Sequence Analysis; D013045:Species Specificity; D013172:Spores, Fungal / Q000166:cytology / Q000254:growth & development
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D005819:Genetic Markers