Detached Maize Sheaths for Live-Cell Imaging of Infection by Fungal Foliar Maize Pathogens.

We have optimized a protocol to inoculate maize leaf sheaths with hemibiotrophic and necrotrophic foliar pathogenic fungi. The method is modified from one originally applied to rice leaf sheaths and allows direct microscopic observation of fungal growth and development in living plant cells. Leaf sheaths collected from maize seedlings with two fully emerged leaf collars are inoculated with 20 µL drops of 5 x 10 spores/mL fungal spore suspensions and incubated in humidity chambers at 23 °C under continuous fluorescent light.

Identification of Quinone Outside Inhibitor Fungicide-Resistant Isolates of from Illinois and Kentucky.

Stagonospora leaf and glume blotch, caused by is a major disease of winter wheat () in the United States capable of significantly reducing grain yield and quality. Pathogens such as that overwinter in crop residue are often an increased concern in cropping systems that utilize no-till farming. In addition, the lack of wheat cultivars with complete resistance to has led to the reliance on foliar fungicides for disease management.

Diversity and Cross-Infection Potential of Causing Fruit Rots in Mixed-Fruit Orchards in Kentucky.

Fungi in the genus cause apple, blueberry, and strawberry fruit rots, which can result in significant losses. Accurate identification is important because species differ in aggressiveness, fungicide sensitivity, and other factors affecting management. Multiple species can cause similar symptoms on the same host, and more than one fruit type can be infected by a single species.

Effects of Phenolic Compounds on Growth of Colletotrichum spp. In Vitro.

Colletotrichum acutatum is responsible for anthracnose fruit rot, one of the most devastating diseases in strawberry. Phenolic compounds have been described as contributors to anthracnose resistance in strawberry (Fragaria x ananassa, Duch.).

The role of a fadA ortholog in the growth and development of Colletotrichum graminicola in vitro and in planta.

A transposon-based split-marker protocol was used to produce insertional mutations in the fadA ortholog of the maize anthracnose pathogen Colletotrichum graminicola. The mutants grew more slowly in culture, produced fewer oval spores, produced fusiform rather than falcate phialospores, lost their normal clockwise spiral growth pattern in culture, and were significantly reduced in their pathogenicity to maize stalks and leaves. The differential effect of the fadA mutation on oval spore versus phialospore production suggests that there are differences in the signaling pathways that regulate these two types of sporulation.

Using mating-type gene sequences for improved phylogenetic resolution of Collectotrichum species complexes.

Colletotrichum species are defined primarily on the basis of host preference and morphology of the organism in planta and in culture. However the genus contains several species complexes that encompass such a broad range of morphological and pathological variation that the species name is of relatively little use either to the taxonomist or plant pathologist. Phylogenetic analyses, primarily based on variable regions of the ribosomal DNA (rDNA) sequences, have indicated that these species complexes comprise a variable number of identifiable monophyletic clades.

CPR1: a gene encoding a putative signal peptidase that functions in pathogenicity of Colletotrichum graminicola to maize.

Colletotrichum graminicola causes anthracnose leaf blight and stalk rot of maize. We used restriction-enzyme mediated insertional (REMI) mutagenesis to identify a gene in this fungus that is required for pathogenicity to both stalks and leaves. The predicted polypeptide encoded by this gene, which we have named CPR1, is similar to a family of proteins that comprise one subunit of the eukaryotic microsomal signal peptidase.

Latent Infection of Austrian and Scots Pine Tissues by Sphaeropsis sapinea.

This study documents latent infection of Austrian and Scots pine tissues by Sphaeropsis sapinea, the causal agent of Sphaeropsis tip blight disease. Symptomless shoots from diseased or apparently healthy Austrian and Scots pine trees were cultured and analyzed for the presence of S. sapinea.

Restriction enzyme-mediated integration used to produce pathogenicity mutants of Colletotrichum graminicola.

We have developed a restriction enzyme-mediated insertional mutagenesis (REMI) system for the maize pathogen Colletotrichum graminicola. In this report, we demonstrate the utility of a REMI-based mutagenesis approach to identify novel pathogenicity genes. Use of REMI increased transformation efficiency by as much as 27-fold over transformations with linearized plasmid alone.