6 Wood Discoloration

8.1 Fungal Damage to Living Trees 167
pathogen if both belong to the same vegetative compatibility group (Haller-
Brem 2001). There are biotechnological attempts for transgenic chestnut trees
(Gartland and Gartland 2004).
8.1.1.3
Plane Canker Stain Disease
The Plane canker stain disease (plane tree canker) (Fig. 8.3) is caused by the
ascomycete Ceratocystis fimbriata f. sp. platani (Wulf 1995). The disease was
for the first time observed on Platanus species in 1926 in the eastern USA
and occurred in the 1940s in Europe [France, Italy, Spain, Switzerland, Turkey;
Clerivet and El Modafar (1994)]. About 80% of the city-trees along motorways
became destroyed until 1950 in the USA. Marseille lost over 1,500 100-year-old
plane trees in 12 years. The fungus penetrates through wounds predominantly
after pruning, more rarely by insects, into the bark of the stem and the branches
and leads to cambium dying and elliptical bark necroses. Later, it colonizes
the outer sapwood with bluish-brown discoloration. Excretion of toxins by
the fungus and tyloses effect wilting of individual crown portions. Thus, the
fungus both produces a bark and a wilt disease (Butin 1995). The trees die
usually within 3–6 years. Reproduction organs are predominantly found on
Fig.8.3. Plane canker stain disease. a Symptoms on plane, b stem cross section showing
stained wood, c tangential stem section showing the stain as streaks, d phialide with conidia
of the Chalara anamorph, e conidiophore with chlamydospores, f perithecium, g ascospores
(from Butin 1995, by permission of Oxford University Press)
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