European Journal of Plant Pathology (2007) 117, 25-33

Willem A. Man in 't Veld, Arthur W.A.M. de Cock and Richard C. Summerbell (2007)
Natural hybrids of resident and introduced Phytophthora species proliferating on multiple new hosts
European Journal of Plant Pathology 117 (1), 25-33
Abstract: Several atypical Phytophthora strains, isolated from a range of horticultural hosts, were tentatively identified as P. cactorum. Numerous abortive oospores were observed in these strains and isozyme analysis showed all were heterozygous for the dimeric malic enzyme (MDHP). More detailed comparisons indicated that their MDHP alleles matched those of both P. cactorum and P. hedraiandra. Cloning and sequencing of the nuclear ribosomal internal transcribed spacer (ITS) regions of the atypical P. cactorum strains demonstrated the presence of sequences characteristic for both P. cactorum and P. hedraiandra. It was concluded that the atypical strains represented hybrids between the resident P. cactorum and the apparently recently introduced P. hedraiandra. Most strains had the mitochondrially inherited cytochrome oxidase I (Cox I) gene typical of one putative parent P. hedraiandra, while one single strain had that of the other putative parent, consistent with the hybrid hypothesis. Our data also suggest that the hybrids are evolving. The hybrids have proliferated on multiple new hosts in the Netherlands.
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Link to article at publishers website
Database assignments for author(s): Willem A. Man in 't Veld, Arthur W.A.M. De Cock

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora cactorum		Netherlands
	Phytophthora hedraiandra		Netherlands