Journal of Plant Pathology (2003) 85, p. 309 (Mannerucci et al.)

F. Mannerucci, R. Ubaldo, G. Campanile, S.L. Giove, A. Gatto, G. Sicoli and N. Luisi (2003)
Occurrence of endophytic fungi in the crown of oak trees in southern Italy
Journal of Plant Pathology 85 (4), 309-309
X Meeting, Italian Society for Plant Pathology (poster)
Abstract: Endophytic fungi are commonly detected in the crown of plants of genus Quercus, especially in declining trees, and their pathogenicity is often a point of discussion among scientists. Preliminary results on the variability and incidence of endophytes collected in 20 oak woods of four regions in southern Italy are reported. In each wood, samples were collected in spring and autumn 2002, from four healthy and/or declining Q. pubescens Willd. and Q. cerris L. adult trees. Isolations were obtained in vitro in agar media in Petri dishes from 30 buds, bark, and wood of 15 one-year-old and 15 three-year-old twigs per species and oak wood. The colonisation frequency of each endophyte was based on the formula CF = (Ni/Nt) x 100 (Ni = number of isolations yielding the same endophyte and Nt = number of all isolations done). The data from the spring survey showed that Discula quercina (West.) v. Arx (CF=17.3%), Biscogniauxia mediterranea (De Not.) O: Kuntze (CF=12.0%) and Aureobasidium pullulans (De Bary) Arn. (CF=5.5%) were the most frequent fungi regardless the Quercus species. Isolations from samples collected in autumn proved that D. quercina was still the most frequent (CF=13.9%), followed by Trichoderma sp. (CF = 12.6%), Botryosphaeria stevensii Shoemaker (CF = 6.4%) and A. pullulans (CF=5.5%), while B. mediterranea was considered as "occasional" (CF<5.0%). Other "occasional" endophytes belonged to the genera Alternaria, Cytospora, Phoma and Phomopsis. In general, D. quercina and A. pullulans occurred mainly in both buds and one-year-old twigs, B. mediterranea was mostly isolated from three-year-old twigs, while 18% of samples did not originate any colonies. This percentage arose to 41% if only wood samples were considered. Since some of the recorded endophytes are well-known weak pathogens, this investigation points out the additional role that endophytes from buds and bark tissues can play in oak decline, especially when trees are weakened by environmental stress factors.

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aureobasidium pullulans	Oak (Quercus)	Italy
	Apiognomonia errabunda	Oak (Quercus)	Italy
	Diplodia mutila	Oak (Quercus)	Italy
	Biscogniauxia mediterranea	Oak (Quercus)	Italy