Journal of Phytopathology (2008) 156, 29-35
A.M. Al-Sa'di, A. Drenth, M.L. Deadman, A.W.A.M. deCock, F.A. Al-Said and E.A.B. Aitken (2008)
Genetic diversity, aggressiveness and metalaxyl sensitivity of Pythium spinosum infecting cucumber in Oman
Journal of Phytopathology 156 (1), 29-35
Abstract: A total of 24 isolates of Pythium spinosum from cucumber obtained from five regions in Oman were characterized for genetic diversity using amplified fragment length polymorphism (AFLP) fingerprinting and three isolates from the Netherlands, South Africa and Japan were included for comparison. Isolates from Oman were also characterized for aggressiveness on cucumber seedlings and sensitivity to metalaxyl. Identity of all isolates was confirmed using sequences of the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA), which showed more than 99% nucleotide similarity among all isolates. Using six primer-pair combinations, AFLP fingerprinting resolved 295 AFLP markers of which 193 were polymorphic among isolates from other countries and only six were polymorphic among isolates of P. spinosum from Oman. Seven different AFLP phenotypes of P. spinosum were recovered in Oman; two of them were found to contain over 79% of isolates and one was recovered from all regions in Oman. Phenotypes from Oman showed very high (>99%) levels of genetic similarity to each other compared to moderate (mean =53%) levels of genetic similarity with phenotypes from other countries. In addition, all isolates from Oman were found to be highly sensitive to metalaxyl and all were aggressive on cucumber seedlings at 25°C. The high genetic similarity among phenotypes of P. spinosum in Oman as well as recovering two major clones across regions may suggest that P. spinosum has been recently introduced in Oman via a common source.
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Link to article at publishers website
Database assignments for author(s): Abdullah Mohammed Al-Sadi, Andre Drenth, Mike L. Deadman
Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
control - general
Pest and/or beneficial records:
Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
---|---|---|---|---|
Globisporangium spinosum | Netherlands | |||
Globisporangium spinosum | Japan | |||
Globisporangium spinosum | South Africa | |||
Globisporangium spinosum | Cucumber (Cucumis sativus) | Oman |