Plant Pathology (2009) 58, 642-654

G.S. Pegg, R.I. Webb, A.J. Carnegie, M.J. Wingfield and A. Drenth (2009)
Infection and disease development of Quambalaria spp. on Corymbia and Eucalyptus species
Plant Pathology 58 (4), 642-654
Abstract: Quambalaria spp. are eucalypt leaf and shoot pathogens of growing global importance, yet virtually nothing is known regarding the manner in which they infect and colonize their hosts. A study of the infection process of Q. pitereka and Q. eucalypti on Corymbia and Eucalyptus species was thus undertaken using light, scanning and transmission electron microscopy after artificial inoculation. Conidial germination was triggered when relative humidity levels exceeded 90% and commenced within 2 h in the presence of free water. Light reduced germination but did not prevent germination from occurring. Conidial germination and hyphal growth occurred on the upper and lower leaf surfaces with penetration occurring via the stomata or wounds on the leaf surface or juvenile stems. There was no evidence of direct penetration of the host. Following penetration through the stomata, Q. pitereka and Q. eucalypti hyphae grew only intercellularly without the formation of haustoria or interaction apparatus, which is characteristic of the order Microstromatales. Instead, the presence of an interaction zone is demonstrated in this paper. Conidiophores arose through stomatal openings producing conidia 7 days after infection.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Geoffrey S. Pegg, Michael J. Wingfield, Angus J. Carnegie, Andre Drenth

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Quambalaria eucalypti	Eucalypt (Eucalyptus)
	Quambalaria eucalypti	Corymbia (crop)
	Quambalaria pitereka	Corymbia (crop)