1. The genetic diversity of ampeloviruses in Australian pineapples and their association with mealybug wilt disease.
- Author
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C. F. Gambley, V. Steele, A. D. W. Geering, and J. E. Thomas
- Subjects
PINEAPPLE ,MEALYBUGS ,WILT diseases ,AMINO acid sequence - Abstract
Pineapple mealybug wilt-associated virus 1 (PMWaV-1), 2 (PMWaV-2) and -3 (PMWaV-3) have been detected in Australian commercial pineapple crops, along with a previously undescribed ampelovirus, for which the name Pineapple mealybug wilt-associated virus 5 (PMWaV-5) is proposed. Partial sequences extending from open reading frame 1b through to the heat shock protein homologue were obtained for PMWaV-1, -3 and -5. Phylogenetic analyses of selected regions of these sequences indicated that PMWaV-5 is a distinct species and most closely related to PMWaV-1. The amino acid sequence variation observed in the RNA-dependent RNA polymerase region of PMWaV-1 isolates was 95.8?98.4% and of PMWaV-3 isolates was 92.2?99.5%. In surveys of mealybug wilt disease (MWD) affected crops, none of the four viruses was clearly associated with the disease at all survey sites. A statistically significant association (P<0.001) between the presence of PMWaV-2 and symptoms was observed at one survey site (site 3), but the virus was at a low incidence at the remaining three survey sites. By contrast, although PMWaV-1 and -3 were equally distributed between symptomless and MWD-affected plants at site 3, there was a statistically significant (P<0.001) association between each of these two viruses and MWD at sites 1 and 4. At site 2, there was a statistically significant (P<0.001) association only between PMWaV-3 and MWD. PMWaV-1 was the most commonly found of the four viruses and conversely PMWaV-5 was only occasionally found. Australian isolates of PMWaV-1, -2 and -3 were transmitted by the mealybug species Dysmicoccus brevipes. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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