Fungicide Sensitivity of from U.S. Soybean and Dry Bean, Compared to Different Regions and Climates.

Fungicide use is integral to reduce yield loss from on dry bean and soybean. Increasing fungicide use against this fungus may lead to resistance to the most common fungicides. Resistance has been reported in Brazil () and China ( subsp.

Species Identification and Fungicide Sensitivity of Fungi Causing Alternaria Leaf Blight and Head Rot in Cole Crops in the Eastern United States.

Alternaria leaf blight and head rot is an important disease of broccoli and other cole crops. With no resistant host varieties, fungicides are utilized to manage this disease. However, anecdotal evidence suggests that, in southeastern U.

Ecological and Morphological Differentiation Among COI Haplotype Groups in the Plant Parasitic Nematode Species .

DNA barcoding with the mitochondrial COI gene reveals distinct haplotype subgroups within the monophyletic and parthenogenetic nematode species, . Biological attributes of these haplotype groups (HG) have not been explored. An analysis of from 40 North American sites representing both native plant communities and agroecosystems was conducted to identify possible subgroup associations with ecological, physiological, or geographic factors.

Evolutionary Significance of Fungal Hypermutators: Lessons Learned from Clinical Strains and Implications for Fungal Plant Pathogens.

Rapid evolution of fungal pathogens poses a serious threat to medicine and agriculture. The mutation rate determines the pace of evolution of a fungal pathogen. Hypermutator fungal strains have an elevated mutation rate owing to certain defects such as those in the DNA mismatch repair system.

Diversity and Aggressiveness of spp. from Nebraska on Soybean and Cross-Pathogenicity to Corn and Wheat.

and -like species of fungi that cause disease are known to have varying host ranges and aggressiveness. Accurate identification of these species causing disease is important for soybean disease management that relies upon crop rotation. The anamorphic genus contains several diverse species and anastomosis groups (AGs) including some known soybean pathogens, such as , whereas for others the ability to cause disease on soybean has not been well described.

Origin of agricultural plant pathogens: Diversity and pathogenicity of Rhizoctonia fungi associated with native prairie grasses in the Sandhills of Nebraska.

The Sandhills of Nebraska is a complex ecosystem, covering 50,000 km2 in central and western Nebraska and predominantly of virgin grassland. Grasslands are the most widespread vegetation in the U.S.

Spontaneous and Fungicide-Induced Genomic Variation in .

Stress from exposure to sublethal fungicide doses may cause genomic instability in fungal plant pathogens, which may accelerate the emergence of fungicide resistance or other adaptive traits. In a previous study, five strains of were exposed to sublethal doses of four fungicides with different modes of action, and genotyping showed that such exposure induced mutations. The goal of the present study was to characterize genome-wide mutations in response to sublethal fungicide stress in and study the effect of genomic background on the mutational repertoire.

Comparative analysis of viruses in four bee species collected from agricultural, urban, and natural landscapes.

Managed honey bees (Apis mellifera L.) and wild bees provide critical ecological services that shape and sustain natural, agricultural, and urban landscapes. In recent years, declines in bee populations have highlighted the importance of the pollination services they provide and the need for more research into the reasons for global bee losses.

Genetic Structure of AG-2-2IIIB from Soybean in Illinois, Ohio, and Ontario.

AG-2-2IIIB is an important seedling pathogen of soybean in North America and other soybean-growing regions around the world. There is no information regarding the population genetics of field populations of associated with soybean seedling disease. More specifically, information regarding genetic diversity, the mode of reproduction, and the evolutionary factors that shape different populations separated in time and space are lacking.

Mitotic Recombination and Rapid Genome Evolution in the Invasive Forest Pathogen .

Invasive alien species often have reduced genetic diversity and must adapt to new environments. Given the success of many invasions, this is sometimes called the genetic paradox of invasion. is invasive, limited to asexual reproduction within four lineages, and presumed clonal.

Population structure and phenotypic variation of from dry bean () in the United States.

The ascomycete pathogen is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on dry bean. Currently, there are no known cultivars of dry bean with complete resistance to white mold. For more than 20 years, bean breeders have been using white mold screening nurseries (wmn) with natural populations of to screen new cultivars for resistance.

Novel gene-sequence markers for isolate tracking within Monilinia fructicola lesions.

Background: Monilinia fructicola is a diverse pathogen of pome and stone fruits that causes severe economic losses each year. However, little is known about inoculum flow within or between orchards and pathogen establishment in an orchard, because few methods exist for detecting diversity or tracking isolates over time. SSR loci are an effective option, but may be confounded by a high degree of mutability and potential sensitivity to abiotic stress.

Effects of Sublethal Fungicides on Mutation Rates and Genomic Variation in Fungal Plant Pathogen, Sclerotinia sclerotiorum.

Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently to five commercial fungicides with different modes of action: boscalid (respiration inhibitor), iprodione (unclear mode of action), thiophanate methyl (inhibition of microtubulin synthesis) and azoxystrobin and pyraclostrobin (quinone outside inhibitors).

Effect of Fungicide Applications on Monilinia fructicola Population Diversity and Transposon Movement.

In this study, we investigated whether fungicide-induced mutagenesis previously reported in Monilinia fructicola could accelerate genetic changes in field populations. Azoxystrobin and propiconazole were applied to nectarine trees at weekly intervals for approximately 3 months between bloom and harvest in both 2013 and 2014. Fungicides were applied at half-label rate to allow recovery of isolates and to increase chances of sublethal dose exposure.

Fungicide-induced transposon movement in Monilinia fructicola.

Repeated applications of fungicides with a single mode of action are believed to select for pre-existing resistant strains in a pathogen population, while the impact of sub-lethal doses of such fungicides on sensitive members of the population is unknown. In this study, in vitro evidence is presented that continuous exposure of Monilinia fructicola mycelium to some fungicides can induce genetic change in form of transposon transposition. Three fungicide-sensitive M.

Characterization of three-dimensional spatial aggregation and association patterns of brown rot symptoms within intensively mapped sour cherry trees.

Background And Aims: Characterization of spatial patterns of plant disease can provide insights into important epidemiological processes such as sources of inoculum, mechanisms of dissemination, and reproductive strategies of the pathogen population. Whilst two-dimensional patterns of disease (among plants within fields) have been studied extensively, there is limited information on three-dimensional patterns within individual plant canopies. Reported here are the detailed mapping of different symptom types of brown rot (caused by Monilinia laxa) in individual sour cherry tree (Prunus cerasus) canopies, and the application of spatial statistics to the resulting data points to determine patterns of symptom aggregation and association.

Influence of bark pH on the occurrence and distribution of tree canopy myxomycete species.

This study compares the occurrence and distribution of myxomycete species in the canopy of living trees and neighboring grapevines. Corticolous myxomycetes of three temperate forests in southeastern USA were studied on six tree species (30 trees) and grapevines (30 vines) to determine distribution and occurrence of myxomycete species relating to geographic location, host species, and bark pH. The double-rope climbing technique was used to access the canopy and sample bark up to 16.