European Journal of Plant Pathology (2017) 148, 97-107

Felix F. Fru, Emma T. Steenkamp, Michael J. Wingfield, Quentin C. Santana and Jolanda Roux (2017)
Unique clones of the pitch canker fungus, Fusarium circinatum, associated with a new disease outbreak in South Africa
European Journal of Plant Pathology 148 (1), 97-107
Abstract: Pitch canker of pines is caused by the fungus Fusarium circinatum. In South Africa, this pathogen has mostly been a nursery problem. From 2005, however, outbreaks of pitch canker have been reported from established Pinus radiata and P. greggii in the Western and Eastern Cape Provinces. Most recently, pitch canker-like symptoms were observed on 10-year-old P. greggii trees in a plantation in the midlands of the KwaZulu-Natal (KZN) Province. The aim of this study was to: (i) identify the causal agent of the observed symptoms, (ii) determine the genetic diversity, and (iii) the mode of reproduction of this fungal population. Furthermore, the aggressiveness of isolates from these trees was compared with that of isolates obtained previously from P. patula in South Africa. Isolates from the P. greggii trees in KZN were confirmed as F. circinatum based on both morphology and DNA sequence analyses. Microsatellite marker analyses revealed the presence of five genotypes of F. circinatum, not previously reported from other plantations in South Africa, with one of these genotypes being dominant. These genotypes were all pathogenic to P. patula and P. elliottii. No evidence of sexual reproduction was detected in the KZN population of the fungus. This was consistent with the fact that isolates from P. greggii were all of the MAT-2 mating type, in contrast to previously collected isolates from across South Africa that included both mating types. The results suggest that the outbreak of pitch canker on P. greggii in KZN represents a separate introduction of F. circinatum into the region with important implications for managing the disease.
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Link to article at publishers website
Database assignments for author(s): Michael J. Wingfield, Jolanda Roux

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Fusarium circinatum	Pine (Pinus)	South Africa