Sooty Blotch, Sclerotium, Cercospora, Fusarium, Cadophora, andPhialophora


Sooty Blotch and Flyspeck of Apple

I have been collaborating with Mark Gleason's students on identifying the fungi that cause sooty blotch and flyspeck signs on apple and other fruit.

Mark has a webpage devoted to this topic: sooty blotch research at ISU

Batzer, J., M. Gleason, T. C. Harrington, and L.H. Tiffany. 2005. Expansion of the sooty blotch and flyspeck complex on apples based on analysis of ribosomal DNA and morphology. Mycologia 97:1268-1286. (pdf file of manuscript).

Duttweiler, K. B., G. Y. Sun, J. C. Batzer, T. C. Harrington, and M. L. Gleason. 2008. An RFLP-based technique for identifying fungi in the sooty blotch and flyspeck complex on apple. Plant Dis. 92: 794-799. (pdf of manuscript)

Batzer, J. C., Diaz Arias, M. M., Harrington, T.C., Gleason, M. L., Groenwald, J. Z., and Crous, P. W.. 2008. Four species of Zygophiala (Schizothyriaceae, Capnodiales) are associated with the sooty blotch and flyspeck complex on apple. Mycologia 100:246-258. (pdf of manuscript)

Díaz Arias, M. M., J. C. Batzer, T. C. Harrington, A. W. Wong, S. C. Bost, D. R. Cooley, M. A. Ellis, J. R. Hartman, D. A. Rosenberger, G. W. Sundin, T. B. Sutton, J. W. Travis, M. J. Wheeler, K. S. Yoder, and M. L. Gleason. 2010. Diversity and biogeography of sooty blotch and flyspeck fungi on apple in the eastern and midwestern United States. Phytopathology 100:345-355.

Batzer, J. C., A. J. Sisson, T. C. Harrington, D. A. Mayfield and M. L. Gleason. 2012. Temporal patterns in appearance of sooty blotch and flyspeck fungi on apples. Microbial Ecology 64:928-941. (pdf of manuscript).


Fusarium

Mbofung, G. Y. C., T. C. Harrington, J. T. Steimel, S. S. Navi, X. B. Yang, and L. F. Leandro. 2012. Genetic structure and variation in aggressiveness in Fusarium virguliforme in the Midwestern United States. Can. J. Plant Pathol. 34:83-97. (pdf of manuscript).


Phytoplasma

Yun, H. Y., and T. C. Harrington. 2011. First report of the walnut witches’ broom phytoplasma on Japanese and black walnut in Iowa. Plant Dis. 95:1474. (links to note and photos)


Boremia

Jones, S. J., F. S. Hay, T. C. Harrington, and S. J. Pethybridge. 2011. First report of Boeremia blight caused by Boeremia exigua var. exigua on pyrethrum in Australia. Plant Dis. 95:1478. (links to note and photos)


Sclerotium

Xu, Zhihan, Harrington, T.C., Gleason, M. L., and Batzer, J C. 2010. Phylogenetic placement of plant pathogenic Sclerotium species among teleomorph genera. Mycologia 102:337-346.


Cercospora

Recent work on Cercospora species on corn was with Pedro Crous and his associates. I played a minor role.

I also am part of a regional project on Cercospora sojina .

Crous, P. W., J. Z. Groenwald, M. Groenwald, P. Caldwell, U. Braun, and T. C. Harrington. 2006. Species of Cercospora associated with grey leaf spot of maize. Studies in Mycology 55:189-197. (pdf of manuscript)

Groenewald, M., J. Z. Groenwald, T. C. Harrington, E. C. A. Abeln, and P. W. Crous. 2006. Mating type gene analysis in apparently asexual Cercospora species is suggestive of cryptic sex. Fungal Gen. Biol. 43:813-825. (pdf of manuscript)


Cadophora

The fungus Phialophora gregata causes an important disease on soybeans, brown stem rot, a vascular wilt disease. There has been considerable confusion over the cause of this disease, so we (Joe Steimel, Fakede Workneh and X. B. Yang in Plant Pathology) more precisely defined the causal agent and designated two races (aggressvie and mild) within the Midwestern USA. This pathogen is now considered a species of Cadophora, we have re-evaluated the species in this genus, which now includes anamorphs of discomycetes (Helotiales) and a number of stain fungi that can cause soft rots of wood in the Antarctic and elsewhere.

Cadophora, wood soft rot

Blanchette, R. A., B. W. Held, J. A. Jurgens, D. L. McNew, T. C. Harrington, S. M. Duncan, and R. L. Farrell. 2004. Wood-destroying soft rot fungi in the historic expedition huts of Antarctica. Apllied and Environmental Microbiology 70: 1328-1335.

You can download a PDF file of this manuscript by clicking here:

 

Cadophora,taxonomy

We also re-evaluated the placement of P. gregata in Phialophora and determined it would be better placed in Cadophora, anamorphs of the Helotiales:

Harrington, T. C. and D. L. McNew. 2003. Phylogenetic analysis places the phialophora-like anamorph genus Cadophora in the Helotiales. Mycotaxon 87:141-151. (Jul-Sep 2003)

You can download a PDF file of this manuscript by clicking here:

 

Cadophora gregata and brown stem rot of soybean

We have identified two races of Cadophora (Phialophora )gregata that differ markedly in their aggressiveness to soybean:

Harrington, T. C., J. Steimel, F. Workneh, and X. B. Yang. 2003. Characterization and distribution of two races of Phialophora gregata in the North Central United States. Phytopathology 93:901-912.

You can download a PDF file of this manuscript by clicking here:

 

Harrington, T. C., J. Steimel, F. Workneh, and X. B. Yang. 2000. Molecular identification of fungi associated with vascular discoloration of soybean in the North Central United States. Plant Dis. 84:83-89.

You can download a PDF file of this manuscript by clicking here: