Frequency of Phaeosphaeria nodorum, the Sexual Stage of Stagonospora nodorum, on Winter Wheat in North Carolina
Open Access
- 1 August 2006
- journal article
- Published by Scientific Societies in Phytopathology®
- Vol. 96 (8), 860-866
- https://doi.org/10.1094/phyto-96-0860
Abstract
Ascocarps of Phaeosphaeria nodorum, which causes Stagonospora nodorum blotch (SNB) of wheat, have not been found by others in the eastern United States despite extensive searches. We sampled tissues from living wheat plants or wheat debris in Kinston, NC, each month except June from May to October 2003. Additional wheat samples were gathered in Kinston, Salisbury, and Plymouth, NC, in 2004 and 2005. For the 3 years, in all, 2,781 fruiting bodies were dissected from the wheat tissues and examined microscopically. Fruiting bodies were tallied as P. nodorum pycnidia or ascocarps, “unknown” (not containing spores, potentially P. nodorum or other fungi), or “other fungi.” In the 2003 sample, asco-carps of P. nodorum were present each month after May at a frequency of 0.8 to 5.4%, and comprised a significantly higher percentage of fruiting bodies from wheat spikes than of those from lower stems and leaves. Ascocarps also were found at frequencies <10% in some wheat debris samples from 2004 and 2005. Analysis of the nucleotide sequences of internally transcribed spacer regions of 18 genetically distinct North Carolina isolates from 2003 suggested that all were P. nodorum, not the morphologically similar P. avenaria f. sp. triticea. Neither the 18 isolates from 2003 nor a set of 77 isolates derived from 2004 Kinston leaf samples gave reason to suspect a mating-type imbalance in the larger P. nodorum population (P ≥ 0.4). We conclude that, in North Carolina, sexual reproduction plays a role in initiation of SNB epidemics and the creation of adaptively useful genetic variability, although its relative importance in structuring this population is uncertain.Keywords
This publication has 38 references indexed in Scilit:
- Variation in cultural characteristics, pathogenicity, vegetative compatibility and electrophoretic karyotype within field populations of Stagonospora nodorumPlant Pathology, 2000
- Intraspecific genetic variation of Stagonospora avenae and its differentiation from S. nodorumMycological Research, 1998
- Gapped BLAST and PSI-BLAST: a new generation of protein database search programsNucleic Acids Research, 1997
- Gene Flow and Sexual Reproduction in the Wheat Glume Blotch Pathogen Phaeosphaeria nodorum (Anamorph Stagonospora nodorum)Phytopathology®, 1997
- Inheritance of Septoria Glume Blotch Resistance in WheatCrop Science, 1993
- First report of the teleomorph of Leptosphaeria nodorum on wheat in South AfricaMycological Research, 1989
- Leptosphaeria nodorum on wheat in IrelandPlant Pathology, 1988
- Confidence Limits on Phylogenies: An Approach Using the BootstrapEvolution, 1985
- A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequencesJournal of Molecular Evolution, 1980
- A FORM OF LEPTOSPHAERIA AVENARIA ON WHEAT IN CANADACanadian Journal of Research, 1947