The Impatiens Downy Mildew Epidemic in the United States Is Caused by New, Introgressed Lineages of with Prominent Genotypic Diversity and High Evolutionary Potential.

Impatiens downy mildew (IDM) caused by is currently the primary constraint on the production and use of impatiens () as bedding plants worldwide. Downy mildew has been documented since the 1880s from wild-grown spp. but epidemic outbreaks of the disease affecting the commercially grown, ornamental were only reported for the first time in 2003 in the United Kingdom and in 2004 in the United States.

Mitochondrial Loci Enable Specific Quantitative Real-Time PCR Detection of the Pathogen Causing Contemporary Impatiens Downy Mildew Epidemics.

Impatiens downy mildew (IDM) disease is a primary constraint on the production of , a popular and economically important floriculture plant. IDM is caused by the biotrophic. oomycete that emerged as a pathogen of in the 2000s.

First report: Co-infection of (sweetbox) by and causes a foliar disease of sweetbox in Pennsylvania.

Sweetbox () are high value ornamental shrubs susceptible to disease caused by () and () (Malapi-Wight et al. 2016; Salgado-Salazar et al. 2019).

Sporangiospore Viability and Oospore Production in the Spinach Downy Mildew Pathogen, .

Downy mildew of spinach, caused by the obligate pathogen , remains the most important constraint in the major spinach production areas in the United States. This disease can potentially be initiated by asexual sporangiospores via "green bridges", sexually derived oospores from seed or soil, or dormant mycelium. However, the relative importance of the various types of primary inoculum is not well known.

One Clonal Lineage of Is Primarily Responsible for the Boxwood Blight Epidemic in the United States.

Boxwood blight caused by and is destroying cultivated and native boxwood worldwide, with profound negative economic impacts on the horticulture industry. First documented in the United States in 2011, the disease has now occurred in 30 states. Previous research showed that global populations prior to 2014 had a clonal structure, and only the idiomorph was observed.

Wheat blast: from its origins in South America to its emergence as a global threat.

Wheat blast was first reported in Brazil in 1985. It spread rapidly across the wheat cropping areas of Brazil to become the most important biotic constraint on wheat production in the region. The alarming appearance of wheat blast in Bangladesh in 2016 greatly increased the urgency to understand this disease, including its causes and consequences.

Wheat Blast: Past, Present, and Future.

The devastating wheat blast disease first emerged in Brazil in 1985. The disease was restricted to South America until 2016, when a series of grain imports from Brazil led to a wheat blast outbreak in Bangladesh. Wheat blast is caused by Pyricularia graminis-tritici ( Pygt), a species genetically distinct from the Pyricularia oryzae species that causes rice blast.

Population Genetic Structure of Rhizoctonia oryzae-sativae from Rice in Latin America and Its Adaptive Potential to Emerge as a Pathogen on Urochloa Pastures.

The fungus Rhizoctonia oryzae-sativae is an important pathogen that causes the aggregated sheath spot disease on rice. In this study, we investigated the genetic structure of rice-adapted populations of R. oryzae-sativae sampled from traditional rice-cropping areas from the Paraíba Valley, São Paulo, Brazil, and from Meta, in the Colombian Llanos, in South America.

Emergence of wheat blast in Bangladesh was caused by a South American lineage of Magnaporthe oryzae.

Background: In February 2016, a new fungal disease was spotted in wheat fields across eight districts in Bangladesh. The epidemic spread to an estimated 15,000 hectares, about 16 % of the cultivated wheat area in Bangladesh, with yield losses reaching up to 100 %. Within weeks of the onset of the epidemic, we performed transcriptome sequencing of symptomatic leaf samples collected directly from Bangladeshi fields.

Resistance to QoI Fungicides Is Widespread in Brazilian Populations of the Wheat Blast Pathogen Magnaporthe oryzae.

Wheat blast, caused by Magnaporthe oryzae, is an important disease across central and southern Brazil. Control has relied mainly on strobilurin fungicides (quinone-outside inhibitors [QoIs]). Here, we report the widespread distribution of QoI resistance in M.

Population structure and pathotype diversity of the wheat blast pathogen Magnaporthe oryzae 25 years after its emergence in Brazil.

Since its first report in Brazil in 1985, wheat blast, caused by Magnaporthe oryzae (anamorph: Pyricularia oryzae), has become increasingly important in South America, where the disease is still spreading. We used 11 microsatellite loci to elucidate the population structure of the wheat blast pathogen in wheat fields in central-western, southeastern, and southern Brazil. No subdivision was found among the wheat-infecting populations, consistent with high levels of gene flow across a large spatial scale.