Botryosphaeriaceae, Botryosphaeriales, Dothideomycetes
SYMPTOMS
Chlorosis of the leaves and leaf dwarfing are the first noticeable symptoms
on the tree, followed by leaf drop showing a regressive death of the leaves
young stems and adult branches. At first glance, the difference between the
affected and healthy branches by the difference in pigmentation of the leaves and of their
size. On closer inspection, you can see the cankers on the stems and the
branches, a cross-section of the affected branches shows the cankers
V-shaped. With the passage of time, we can observe the continuous deterioration that causes
Sardiniella urhana on Celtis australis to defoliate large areas of the tree
losing photosynthetic surface area and causing the death of large branches, which leads to
fear for the safety of people in the cities where Celtis australis
are planted as alignment trees.
Figure A -B Conidiomata on substrate; C Conidiomata section; D-E Conidia
F Young conidia; G Tree affected by
decay caused by Sardiniella urbana. Scale bar B – C 100 µm, D 5 µm.
E-F10 µm
DESCRIPTION
Conidioma: picnidial, unilocular, ostiolado, glabro, piriforme, 210-320 x 140-200 µm,
angular textured outer wall, 40-50 µm thick, composed of five to seven layers
of brown polyhedral cells in the eternal layers to subhyaline cells in the
internals. Conidiogenous cells proliferate percurrently, forming in the apex
inconspicuous, hyaline, cylindrical annulations. Conidium solitary, initially hyaline,
brown and bicellular at maturity, with a medial septum, thick-walled, rough, ellipsoidal to
ovoid, 19-26 x 9-15 µm. Colonies on PDA and MEA 2%, grow 80mm after 7 days, velvety texture with irregular margins, white turning green
Dark when mature, dark grey reverse, NOTES
In Palma de Mallorca, Sardiniella urbana has been isolated from Celtis australis and on
Celtis occidentalis, from both affected parts and healthy stems behaving as
endophytic organism. We have found Sardiniella urbana in saplings, trees,
juveniles, adults and individual trees, this being a very widespread disease in
Mallorca and throughout the Meditophranco basin.
BIBLIOGRAPHY
https//www.indexfungorum.org/
Linaldeddu BT., Alves A., Phillips AJL. Mycosphere 7 (7): 900 (2016). Sardiniella
urbana gen. et sp. nov., a new member of the Botryosphaeriaceae isolated from
declining Celtis australis tres in Sardinian streetscapes
Angel Pintos Amengual, Alberto M. Sttchigel, Jose Cano F. Cano Lira. Plant Disease
Vol. 105 No. 11. First Report of Sardiniella urbana (Botryosphaeriaceae) Causing
Decline of Celtis australis in Mallorca Island (Balearic Islands, Spain).
Sardiniella Urbana fungus
