Assessing Biofungicides and Host Resistance against Rhizoctonia Large Patch in Zoysiagrass.

Rhizoctonia large patch ( AG2-2 LP) significantly reduces turfgrass quality, aesthetics, and playability. Synthetic fungicides are commonly used for managing this disease, but they present high costs, potential for fungicide resistance, and environmental concerns. We conducted in vitro assays to test the effectiveness of three biofungicides, seven synthetic fungicides, and ten combinations against .

Probe-Based Loop-Mediated Isothermal Amplification Assay for Rapid Detection of Two spp., the Causal Agent of Dollar Spot of Turfgrass.

Dollar spot is a major fungal disease affecting turfgrass worldwide and can quickly destroy turfgrass swards. An assimilating probe-based loop-mediated isothermal amplification (LAMP) assay was developed to detect and , the causal agents of dollar spot within the continental United States. Five LAMP primers were designed to target the calmodulin gene with the addition of a 6-carboxyl-fluorescein florescent assimilating probe, and the temperature amplification was optimized for and identification.

Genetic Diversity, Mycotoxin Profiles, and Population Structure of spp Associated with Fusarium Head Blight in Georgia, United States.

Fusarium head blight (FHB) has become a limiting factor in soft red winter wheat production in the southeast United States. Recent epidemics have occurred in Georgia, but genetic information on the species responsible for FHB is unknown. This study aimed to assess pathogen population structure and genetic diversity, trichothecene profiles, and representative pathogenicity of 196 isolates collected from 44 wheat ( = 85) and 53 corn ( = 111) fields in Georgia.

Sensitivity of spp. to benzimidazoles and dimethyl inhibitors fungicides and efficacy of biofungicides on dollar spot of warm season turfgrass.

Dollar spot caused by spp. (formerly ) is an economically destructive fungal disease of turfgrass that can significantly compromise turf quality, playability, and aesthetic value. Fungicides are frequently used to manage the disease but are costly and potentially unfavorable to the environment.

Genetics of Fusarium head blight resistance in soft red winter wheat using a genome-wide association study.

Host resistance is an effective and sustainable approach to manage the negative impact of Fusarium head blight (FHB) on wheat (Triticum aestivum L.) grain yield and quality. The objective of this study was to characterize the phenotypic responses and identify quantitative trait loci (QTL) conditioning different FHB resistance types using a panel of 236 elite soft red winter wheat (SRWW) lines in a genome-wide association study (GWAS).

New Approaches to an Old Problem: Dollar Spot of Turfgrass.

Dollar spot, caused by fungal pathogens spp. (formerly ), is the most common and widely distributed disease of turfgrass worldwide. It can drastically reduce the quality of turfgrass species and affect their aesthetic value and playability.

First report of the stubby-root nematode infecting , seashore paspalum grass in Georgia, USA.

We found that spp. was pathogenic to seashore paspalum () turfgrass as its population increased from 100 to 2,080 nematodes per pot 180 days after inoculation under greenhouse conditions. Morphological measurements of adult females were similar to those described for .

Turfgrass Disease Diagnosis: Past, Present, and Future.

Turfgrass is a multibillion-dollar industry severely affected by plant pathogens including fungi, bacteria, viruses, and nematodes. Many of the diseases in turfgrass have similar signs and symptoms, making it difficult to diagnose the specific problem pathogen. Incorrect diagnosis leads to the delay of treatment and excessive use of chemicals.

Evaluating the impact of turf-care products on soil biological health.

Golf courses require extensive use of inputs to meet the needs of playability and aesthetics. The impact of these inputs on soil biological health is largely unknown. Two field trials were conducted at a golf course in Georgia to evaluate short-term effects of wetting agents (Cascade Plus and Duplex [C+D], Revolution [Rev]), plant growth regulators (PrimoMaxx [PM] and Cutless [CL]), and a product called PlantHelper (PH) on soil biological health by measuring microbial abundance and function.

Fusarium Head Blight and Rust Diseases in Soft Red Winter Wheat in the Southeast United States: State of the Art, Challenges and Future Perspective for Breeding.

Among the biotic constraints to wheat ( L.) production, fusarium head blight (FHB), caused by , leaf rust (LR), caused by , and stripe rust (SR) caused by are problematic fungal diseases worldwide. Each can significantly reduce grain yield while FHB causes additional food and feed safety concerns due to mycotoxin contamination of grain.

Ubc2, an ortholog of the yeast Ste50p adaptor, possesses a basidiomycete-specific carboxy terminal extension essential for pathogenicity independent of pheromone response.

Proteins involved in the mitogen-activated protein (MAP) kinase pathway controlling mating, morphogenesis, and pathogenicity have been identified previously in the fungus Ustilago maydis. One of these, the Ubc2 adaptor protein, possesses a basidiomycete-specific structure. In addition to containing sterile alpha motif (SAM) and ras association (RA) domains typical of Ste50-like adaptor proteins found in the fungal phylum Ascomycota, Ubc2 also contains two C-terminal SH3 domains.

Infection of alternative host plant species by Ustilago maydis.

•  Here, the host specificity of the corn smut fungus Ustilago maydis was analyzed, with the long-term objective of understanding the different aspects of its pathogenic behavior. •  Axenic plantlets obtained in vitro, including one gymnosperm, monocotyledons and dicotyledons, were inoculated with a diploid strain of U. maydis, incubated in a growth chamber, and observed periodically.

MAP kinase and cAMP signaling pathways modulate the pH-induced yeast-to-mycelium dimorphic transition in the corn smut fungus Ustilago maydis.

Acid pH induces the yeast-to-mycelium transition in haploid cells of Ustilago maydis. We tested two signal transduction pathways known to be involved in dimorphism for roles in acid-induced filamentation. In wild-type cells intracellular cAMP levels were reduced under acid growth.

Cloning and expression analysis of the ornithine decarboxylase gene (PbrODC) of the pathogenic fungus Paracoccidioides brasiliensis.

We describe the isolation and sequencing of PbrODC, the gene encoding ornithine decarboxylase (ODC) in Paracoccidioides brasiliensis. The gene contains a single open reading frame made of 1413 bp with a single intron (72 bp), and encodes a 447 amino acid polypeptide with a predicted molecular weight of 50.0 kDa, an isoelectric point of 4.

Use of PCR to detect infection of differentially susceptible maize cultivars using Ustilago maydis strains of variable virulence.

Ustilago maydis was specifically detected in infected maize plants by means of the polymerase chain reaction (PCR) using oligonucleotides corresponding to a specific region downstream of the homeodomain of the bE genes of the pathogen. The reaction gave rise to amplification of a ca. 500-bp product when tested with U.

The Ustilaginales as plant pests and model systems.

The Ustilaginales are a vast and diverse group of fungi, which includes the plant pathogenic smuts that cause significant losses to crops worldwide. Members of the Ustilaginales are also valuable models for the unraveling of fundamental mechanisms controlling important biological processes. Ustilago maydis is an important fungal model system and has been well studied with regard to mating, morphogenesis, pathogenicity, signal transduction, mycoviruses, DNA recombination, and, recently, genomics.

Integration of the gene for carboxin resistance does not impact the Ustilago maydis-maize interaction.

A previous report indicated that insertion of the carboxin resistance (cbxR) gene into the Ustilago maydis genome impaired the pathogenic ability of the fungus towards Zea mays, the corn host. Because we had anecdotal evidence from work in our laboratory that this was not necessarily the case we decided to determine how general was the observation of reduced pathogenicity associated with cbxR. To accomplish this we tested the pathogenicity of several strains that had been transformed with the cbxR gene and compared them with non-transformed strains or strains transformed with the gene conferring hygromycin resistance which is a commonly used selectable marker in this fungus.

Double chitin synthetase mutants from the corn smut fungus Ustilago maydis.

Using genetic crosses between single chs mutants of Ustilago maydis inoculated into maize (Zea mays) seedlings, two classes of double mutants affected in genes coding for chitin synthetases were isolated: chs3/chs4, and chs4/chs5. Analysis of the mutants showed almost no change in their phenotype compared with wild-type strains. Growth rate, effect of stress conditions, dimorphic transition and mating were not affected.