Showing papers by "Conrad L. Schoch published in 1999"
TL;DR: In this article, Cylindrocladium candelabrum-like isolates were collected from a wide variety of geographic lo- cations and compared based on their morphology, sexual compatibility and the nucleotide sequences of their rDNA ITS regions.
Abstract: Cylindrocladium candelabrum-like isolates were collected from a wide variety of geographic lo- cations and compared based on their morphology, sexual compatibility and the nucleotide sequences of their rDNA ITS regions. All isolates included in this study mated to produce Calonectria teleomorphs with viable progeny. Four distinct mating populations were identified, each representing a genetically iso- lated, biallelic, heterothallic population. Several rep- resentative isolates of each mating population, re- flecting geographic diversity, were chosen for se- quence comparisons. The internal transcribed spacer (ITS) regions 1 and 2 that flank the 5.8S rDNA gene, as well as the gene itself, were sequenced and com- pared. All isolates representing the same group yield- ed similar sequences, but small, consistent differenc- es were found between the groups. Based on these results we recognise Calonectria scoparia (anamorph Cylindrocladium candelabrum), and describe three new species, namely Calonectria pauciramosa (ana- morph Cylindrocladium pauciramosum), Calonectria insularis (anamorph Cylindrocladium insularae) and Calonectria mexicana (anamorph Cylindrocladium mexicanum).
63 citations
TL;DR: Although species differences based on ITS sequences were consistent, there were only a few informative sites available, making it difficult to clearly identify the unknown strains, and better resolution in separation of species was achieved from the beta-tubulin data.
Abstract: Unidentified strains of Cylindrocladium that were baited from soil in the Amazonas state of Brazil or isolated from Adiantum in the Netherlands were examined morphologically and analysed phylogenetically in comparison with reference strains. Phylogenetic trees inferred from the 5.8S subunit and flanking internal transcribed spacers (ITS1 and ITS2) of rDNA, as well as the beta-tubulin gene, separated species in accordance with their morphological features and characteristics. Although species differences based on ITS sequences were consistent, there were only a few informative sites available, making it difficult to clearly identify the unknown strains. Better resolution in separation of species was achieved from the beta-tubulin data. The strains baited from soil in Brazil were found to represent two species, namely Cylindrocladium gracile (Bugnic.) Boesew. and Cylindrocladium pseudogracile Crous. Morphologically, these two species are similar, except that the latter has slightly narrower, 1(-3)-septate c...
38 citations
TL;DR: This is the first report of C. pauciramosum as a pathogen of heath, and the first record of this pathogen from North America.
Abstract: Heath (Erica capensis Salter) is a woody, evergreen plant used in Cali-fornia as a landscape shrub or ground cover In 1997, a new root and crown disease was found in commercial nursery plantings of potted heath A similar disease was found in 1998 on heath transplants being grown as liners In both situations, roots were necrotic and crown tissue turned brown Affected plants became gray-green in color, withered, and died A Cylindrocladium species was consistently isolated from roots, crowns, and lower stems of symptomatic plants Isolates were characterized by having penicillate conidiophores terminating in obpyriform to broadly ellipsoidal vesicles Conidia were hyaline, 1-septate, straight with rounded ends, (30-) 45 to 55 (-60) × (35-) 4 to 5 μm, placing it in the Cylindrocladium candelabrum Viegas species complex Ten single-conidial isolates produced perithecia with viable progeny of Calonectria pauciramosa CL Schoch & Crous when mated on carnation leaf agar with tester strains of Cylindrocladium pauciramosum CL Schoch & Crous (1) Matings with tester strains of all other species in this complex proved unsuccessful Pathogenicity of 8 representative isolates was confirmed by applying 3 ml of a conidial suspension (30 × 105 conidia per ml) to the crowns of potted, 6-month-old, rooted heath cuttings that were subsequently maintained in a greenhouse (23 to 25°C) After 2 weeks, plant crowns and roots developed symptoms similar to those observed in the field, and plants later wilted and died C pauciramosum was reiso-lated from all plants Control plants, which were treated with water, did not develop any symptoms The tests were repeated and the results were similar This is the first report of C pauciramosum as a pathogen of heath, and the first record of this pathogen from North America Reference: (1) C L Schoch et al Mycologia 91:286, 1999
19 citations
TL;DR: Koch’s postulates are proven for this fungus and possible disease control measures are discussed.
6 citations