DNA reassociation was used to estimate GC content, size, and complexity of the nuclear genomes of Colletotrichum from maize and sorghum. Melting-temperature analysis indicated that the GC content of the maize pathotype DNA was 51% and that the GC content of the sorghum pathotype was 52%. DNA reassociation kinetics employing S1 nuclease digestion and an appropriately modified second-order equati...

Severity of Verticillium wilt in olive trees in Andalusia, southern Spain is associated with the spread of a highly virulent, defoliating (D) Verticillium dahliae pathotype of vegetative compatibility group 1A (VCG1A) but the extent of this spread and the diversity of the pathogen population have never been documented. VCG typing of 637 V. dahliae isolates from 433 trees in 65 orchards from fiv...

Sorghum downy mildew, caused by the obligate oomycete Peronosclerospora sorghi, has been controlled through the use of resistant cultivars and seed treatment with metalaxyl. A recent outbreak in fields planted with treated seed revealed the presence of a metalaxyl-resistant variant. Here, PCR-based methods including amplification from RAPD primers and two systems of automated AFLP analysis have...

Advanced backcross families derived from Oryza sativa cv MR219/O. rufipogon IRGC105491 were utilized for identification of quantitative trait loci (QTL) for blast resistance using simple sequence repeat markers. Two hundred and sixty-one BC(2)F(3) families were used to construct a linkage map, using 87 markers, which covered 2375.2 cM of 12 rice chromosomes, with a mean density of 27.3 cM. The ...

Bursaphelenchus xylophilus isolate MPSy-1av was subcultured from pathotype MPSy-1. MPSy-1av is nonparasitic and does not establish in Pinus sylvestris, P. strobus, P. nigra, or P. taeda. This isolate produces ethanol as an end product of carbohydrate metabolism, whereas its parent pathotype, MPSy-1, does not. Alcohol dehydrogenase activity was easily detectable in homogenates of MPSy-1av but ba...

Alternaria brown spot disease is caused by the alternata tangerine pathotype, which relies on ACT-toxin for infection. At present, all identified biosynthesis-related genes are multi-copy genes. In this study, we summarized advances in important host-specific toxins (HSTs), and listed key required pathogenicity of A. pathotype. Toxin virulence test results revealed that different citrus species...

BACKGROUND Development of Verticillium wilt in olive, caused by the soil-borne fungus Verticillium dahliae, can be influenced by biotic and environmental factors. In this study we modeled i) the combined effects of biotic factors (i.e., pathotype virulence and cultivar susceptibility) and abiotic factors (i.e., soil temperature) on disease development and ii) the relationship between disease se...

spot blotch caused by bipolaris sorokiniana is a serious disease of barley in western canada. it has become the predominant barley leaf spot disease in the province of manitoba, canada, since 2001. a new pathotype of b. sorokiniana with virulence on seedlings of ‘resistant’ six-rowed barley cultivars grown in manitoba was recently identified. to determine the adult plant infection response of b...

Turnip mosaic virus (TuMV), a species of the genus Potyvirus, occurs worldwide. Seventy-six isolates of TuMV were collected from around the world, mostly from Brassica and Raphanus crops, but also from several non-brassica species. Host tests grouped the isolates into one or other of two pathotypes; Brassica (B) and Brassica-Raphanus (BR). The nucleotide sequences of the first protein (P1) and ...