Description of the parasite

The first isolations carried out at the end of the 1980s (Maluta and Larignon, 1991) made it possible to regularly identify a soil fungus, called at the time Cylindrocarpon destructans (Zinsmeister) Scholten. The frequency of isolation of this type of fungus and the reproduction of necrotic lesions on the underground parts of inoculated cuttings have made it possible to demonstrate its parasitic role. Since then, advances in taxonomy have made it possible to associate the symptoms of Black footwith two fungal genera, Cylindrocarpon and Campylocarpon , and several related species. It is therefore very likely that many isolates, previously identified as C. destructans , actually belonged to the main species now recognized Cylindrocarpon liriodendri (JD Mac Donald and EE Butler), and sometimes to other species described in different countries: Cylindrocarpon macrodidymum Schroers, Halleen & Crous (South Africa, Australia, California and New Zealand), Cylindrocarpon obtusisporum (Cooke & Harness) Wollew. (Sicily, California), Campylocarpon fasciculare Schroers, Halleen and Crous and Campylocarpon pseudo-fasciculare Halleen, Schroers and Crous (South Africa).

We will only describe the anamorphic and teleomorphic forms of the most common species C. liriodendri.

• It forms conidiophores isolated or united in the form of sporodochia . At their end, we can observe macro or micro-conidia . The first, predominant, are cylindrical and sometimes slightly curved, and present from 1 to 3 partitions as well as a hilum. They measure 35-40 x 5.5-6 µm. The rarer micro-conidia reveal 0 to 1 septum. They can be ellipsoid to subcylindrical (5-15 x 2.5-4 µm) or ovoid (3-5 x 3-4 µm) with a lateral hilum.
• Of chlamydospores are commonly seen: they are ovoid to ellipsoid and often associated with short chains. They are medium brown in color and have the following dimensions: 10-20 x 10-17 µm.
• Mushroom heterothallic, Ilyonectria liriodendri (Halleen Rego & Crous, sp.nov.)  As in vitro of perithecia singly or in groups, the latter has not yet been observed in nature. This is why some authors prefer to name this fungus under the name of its anamorphic or asexual form which is the only one present in vine wood.