ISHS Acta Horticulturae 619: XXVI International Horticultural Congress: Potatoes, Healthy Food for Humanity: International Developments in Breeding, Production, Protection and Utilization
TRANSMISSION AND CHARACTERIZATION OF PHYTOPLASMA DISEASES ASSOCIATED WITH INFECTED POTATO CULTIVARS IN ALBERTA |
| Authors: | A.-H. Khadhair, P. Duplessis McAlister, K. Ampong-Nyarko, P. Bains |
| Keywords: | Leafhoppers, transmission, potato tubers, DNA, PCR, RFLP |
| Abstract:
A population dynamic study was conducted on leafhopper insects associated with the transmission of phytoplasma diseases. This study was undertaken on a total of nine potato fields throughout Alberta. Our initial data indicate a variation in leafhopper population directly proportional to environmental conditions and plant development. A total of 63 potato plants, representing 10 different cultivars, and showing typical phytoplasma symptoms, were collected after full germination during rouging practices. A representative sample of each cultivar was tested using molecular assays to detect and identify the infecting phytoplasma. In all of the samples tested, potato witches'-broom (PWB) and purple top (PT) phytoplasmas were positively identified by specific DNA testing. These two phytoplasmas were identified by DNA amplification with two universal primer pairs (P1/P7 and R16 F2n/R2) and two specific primer pairs (R16 F1/R1 and 1A/1B). DNA amplification with specific polymerase chain reaction (PCR) primer pairs indicated that aster yellows (AY) phytoplasma was present in a mixed infection with PWB phytoplasma but in a very low DNA concentration. Based on RFLP analyses, PWB and PT phytoplasmas were found to belong to the clover proliferation and AY phytoplasma groups, respectively. The results from this study may suggest that AY and PWB phytoplasmas were associated with tubers collected from infected potato plants from the previous season. | |
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