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Spatiotemporal changes in the population structure of Botryosphaeria dothidea from California pistachio orchards

Ma, Z., Luo, Y., Michailides, T.J.
Phytopathology 2004 v.94 no.4 pp. 326-332
Pistacia vera, pistachios, blight, Botryosphaeria dothidea, plant pathogenic fungi, disease prevalence, spatial distribution, geographical distribution, temporal variation, orchards, inoculum density, polymerase chain reaction, DNA-directed RNA polymerase, genes, gene amplification, microsatellite repeats, nucleotide sequences, vegetative growth, California, Georgia, South Carolina, North Carolina, Illinois, Pennsylvania
Spatiotemporal changes in the population structure of Botryosphaeria dothidea, causal agent of panicle and shoot blight of pistachio, were analyzed by using microsatellite-primed polymerase chain reaction (MP-PCR), partial sequences of the RNA polymerase II (RPB2) gene, and vegetative compatibility groups (VCGs). We examined 390 isolates, 378 recovered from pistachio in seven counties of California from 1990 to 2001 and 12 recovered from peach, apple, and sycamore in Georgia, North Carolina, South Carolina, Illinois, and Pennsylvania. Six microsatellite primers generated 116 polymorphic bands. Based on MP-PCR data, we observed very high (>98%) levels of genetic identity among populations of B. dothidea collected from the commercial pistachio orchards in California. The near identity of these populations was supported by VCGs and partial sequences of the RBP2 gene. These findings suggest that populations of B. dothidea from commercial pistachio orchards are spatially and temporally stable, at least in the past 5 years.