The pinewood nematode, Bursaphelenchus xylophilus, is native to North America but it only causes damaging pine wilt disease in those regions of the world where it has been introduced. The accurate detection of the species and its dispersal routes are thus essential to define effective control measures. The main goals of this study were to analyse the genetic diversity among B. xylophilus isolat...

seven geographic isolates of helicoverpa armigera npv were characterized by pcr-rflp techniques and their comparative virulence to second instar larvae of h. armigera (hã¼bner) were compared before and after exposure to simulated sunlight as well as open weather conditions on cotton and tomato plants. the pcr products of 25k fp region showed no difference among the isolates (780 bp). the pcr am...

We used RAPD (random amplification of polymorphic DNA) to analyze the phenotypic and genotypic characteristics of Sporothrix schenckii isolated from five geographic regions of Brazil, from clinical, animal, and environmental sources. Our results yielded a significant difference (P<0.01) in the mean conidial area of S. schenckii animal isolates (2.96 ± 1.07) compared with those of clinical isola...

Global-scale data on the Oligocene to Recent planktic foraminifers and coccoliths from the tropical Pacific and Atlantic Oceans are employed for quantitative testing of alternative models (Red Queen and Stationary Hypotheses) of the relationship between speciation rates, extinction rates, taxonomic diversity, abiotic events, and history of the paleosystem. The results demonstrate that although ...

Objective: The aim of this study was to estimate genetic variability and phonetic relationships of 50 isolates of P. sojae from Iran. Methods: During 2005–2007, 142 isolates of Phytophthora sojae were collected from soil samples and diseased soybean plants from Lorestan, Mazandaran, Golestan and Ardabil provinces. Races of the isolates were determined. DNA of P. sojae...

Objective: The aim of this study was to estimate genetic variability and phonetic relationships of 50 isolates of P. sojae from Iran. Methods: During 2005–2007, 142 isolates of Phytophthora sojae were collected from soil samples and diseased soybean plants from Lorestan, Mazandaran, Golestan and Ardabil provinces. Races of the isolates were determined. DNA of P. sojae...

Background: The tan spot disease of wheat caused by Pyrenophera tritici-repentis has become a major disease in most wheat growing areas worldwide. Objectives: Here we used ISSR and RAPD markers to study the genetic diversity of 34 P. tritici-repentis isolates collected from North of Iran. Materials and Methods: The leaves having the typical symptoms of tan spot disease were collected and after...

Numerous outbreaks of cholera have occurred in Kenya since 1971. To more fully understand the epidemiology of cholera in Kenya, we analyzed the genetic relationships among 170 Vibrio cholerae O1 isolates at 5 loci containing variable tandem repeats. The isolates were collected during January 2009-May 2010 from various geographic areas throughout the country. The isolates grouped genetically int...

Verticillium dahliae is a fungal pathogen that causes wilt disease in a wide range of host plants. Characterization of virulence, morphological, and molecular variations among V. dahliae isolates from different geographic origins is essential for any breeding program aimed at producing plant cultivars resistant to this disease. We characterized virulence variation among V. dahliae isolates...

The limited host range of Enterococcus faecalis may reduce its clonal diversity and thereby increase its geographic sharing of ribotype patterns. Such sharing would be advantageous for bacterial source tracking (BST). We determined the geographic sharing of ribotype patterns in 752 Ent. faecalis isolates obtained primarily from wastewater treatment plants in Delaware (15 locations; 490 isolates...