Genetic and Virulence Variability Among Erwinia tracheiphila Strains Recovered from Different Cucurbit Hosts

Low genetic diversity among pathogenic strains of Erwinia psidii from Brazil

Erwinia psidii causes bacterial disease of guava in Brazil. Phenotypic and molecular characterization through rep-PCR fingerprinting of 42 strains from different geographical regions showed that E. psidii populations in Brazil have a low level of genetic diversity and suggest that contaminated plant material is the main source for pathogen dissemination in the country.

The Serological Relationship Between Erwinia tracheiphila and Species of Shigella.

Genetic diversity of Spiroplasma citri strains from different regions, hosts, and isolation dates.

Spiroplasma citri, a phloem-limited pathogen, causes citrus stubborn disease (CSD). Losses due to CSD in California orchards have grown over the past decade. To investigate the possibility of introduction or emergence of a new strain, a study of genetic diversity among S. citri strains from various locations was conducted using random amplified polymorphism DNA-polymerase chain reaction (RAPD-P...

Virulence and Genetic Variability Among Isolates of Mycosphaerella pinodes

Mycosphaerella blight, caused by Mycosphaerella pinodes (Berk. & Bloxam) Vestergr., is the most important foliar disease of field pea (Pisum sativum L.) worldwide (2,7,16,17,23,30,31). In Canada, average dry seed yield losses caused by this disease have been estimated at 10%, and losses of over 50% have been reported in field trials (28,34). Management for Mycosphaerella blight is limited to fu...

Sequence variation in the Toxoplasma gondii ROP20 gene among strains from different hosts and geographical locations.

Toxoplasma gondii, an opportunistic protozoan parasite, infects almost all warm-blooded animals. In this study, we examined the sequence variation in rhoptry protein 20 (ROP20) genes among 18 T. gondii isolates collected from different hosts and geographical regions. Full length ROP20 genes were amplified and sequenced. The results showed that the genes were 1659 bp in length and contained only...