In North America there are two generally recognized pathotypes (pathotypes 1 and 2) of the fungus Entomophaga grylli which show host-preferential infection of grasshopper subfamilies. Pathotype 3, discovered in Australia, has a broader grasshopper host range and was considered to be a good biocontrol agent. Between 1989 and 1991 pathotype 3 was introduced at two field sites in North Dakota. Sin...

This study was carried out to better understand factors that influenced the process of attenuation of Marek's disease (MD) virus by serial passage in cell cultures. Three virulent (v) pathotype and three very virulent plus (vv+) pathotype strains were passed by three techniques up to 131 times, and the passage level at attenuation was determined. The 18 attenuated or partially attenuated viruse...

Canadian isolates of Leptosphaeria maculans, the causal agent of blackleg of crucifers, were examined for genetic relatedness by the random amplified polymorphic DNA assay. DNA polymorphisms amplified with random decamer primers were used to distinguish three groups of isolates. Group 1 contained all isolates of the virulent pathotype, group 2 contained isolates of the avirulent pathotype from ...

Pines responded to inoculation with Bursaphelenchus xylophilus by changes in reducing and nonreducing carbohydrate concentrations dependent on the pine species and the pathotype of B. xylophilus with which the trees were inoculated. Carbohydrate concentrations, in compatible pine-nematode pathotype combinations, decreased initially after inoculation and then increased slightly before decreasing...

A number of rice resistance genes, called Xa genes, have been identified that confer resistance against various strains of Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight. An understanding of pathotype diversity within the target pathogen population is required for identifying the Xa genes that are to be deployed for development of resistant rice cultivars. Among 1024 ...

Blight disease, caused by Ascochyta rabiei (Pass.) Labrousse (teleomorph=Didymella rabiei), is one of the most important biotic stress factors affecting chickpea produc tion worldwide. The high variation in disease severity among different cul tivars and decrease resistance cultivars over time make it necessary to test regularly. aim this research was determine evalu ate changes susceptibility ...

background and objectives: diarrheagenic escherichia coli (dec) is an emerging agent among pathogens that causes diarrhea. studies showed that diarrheagenic e. coli such as enterohaemorrhagic e. coli (ehec), enteroaggregative e. coli (eaec), enteropathogenic e. coli (epec), enteroinvasive e. coli (eiec), enterotoxigenic e. coli (etec), diffusely adhering e. coli (daec) and shiga toxin producing...

The tomato pathotype of Alternaria alternata produces host-specific AAL toxin and causes Alternaria stem canker on tomato. A polyketide synthetase (PKS) gene, ALT1, which is involved in AAL toxin biosynthesis, resides on a 1.0-Mb conditionally dispensable chromosome (CDC) found only in the pathogenic and AAL toxin-producing strains. Genomic sequences of ALT1 and another PKS gene, both of which ...

The purpose of this study was to compare avian pathogenic Escherichia coli (APEC) isolates to fecal isolates of apparently healthy poultry (avian fecal E. coli or AFEC) by their possession of various traits in order to ascertain whether APEC and AFEC are distinct and if the APEC strains constitute a distinct pathotype. Four hundred and fifty-one APEC and one hundred and four AFEC isolates were ...

The tangerine pathotype of Alternaria alternata produces the A. citri toxin (ACT) and is the causal agent of citrus brown spot that results in significant yield losses worldwide. Both the production of ACT and the ability to detoxify reactive oxygen species (ROS) are required for A. alternata pathogenicity in citrus. In this study, we report the 34.41 Mb genome sequence of strain Z7 of the tang...