The wound pathogen Chondrostereum purpureum, its history and incidence on trees in North America

Abstract

Since Percival's inoculation studies in 1902 with the wound pathogen Chondrostereum purpureum (Pers.�:�Fr.) Pouz. on plum trees in England, this fungus has become well known as the cause of silver-leaf disease of rosaceous fruit trees. However, its pathological impact on forest trees has been little studied and appreciated. Therefore, the question is raised about the pathogenic role and incidence of C. purpureum on other trees in damaged forests. A survey of 561 collections of this fungus in herbaria of Canada and the United States found that the highest incidence occurred in the Betulaceae (45%), especially Betula (27%) and Alnus (15%). The second-most favoured host family was the Salicaceae (20%) with a 15 and 5% occurrence on Populus and Salix, respectively. The third-most favoured substrate was apparently the Rosaceae at 11%, but this reflected a bias of agricultural research in orchards. A 6% incidence was found in the Fagaceae, 4% in the Aceraceae and 3% in the Ulmaceae. From 1 to 3% of the collections occurred for each of the Cornaceae, Juglandaceae, Magnoliaceae and Pinaceae. Incidences <1% were indicated for each of the Aquifoliaceae, Caprifoliaceae, Cupressaceae, Grossulariaceae, Hamamelidaceae, Hippocastanaceae, Myrtaceae, Oleaceae, Rhamnaceae and Tiliaceae. The host survey data indicate that C.�purpureum is an important pathogen with epidemic potential in forest trees, especially species in the Betulaceae and Salicaceae. The silvering symptom is inconspicuous in birch and other non-rosaceous trees. Forests with greatest vulnerability are those subjected (1) to physical forces that cause stem injuries to susceptible trees, (2) to environmental conditions conducive for infection and (3) to high levels of basidiospore inoculum from fruiting bodies on hardwood slash that result from timber harvesting and storm damage. Silver-leaf is an important fungal disease of many tree species in North America and is largely responsible for the birch dieback in North American forests. Control data from several mycoherbicide experiments support this conclusion.

Biological control of intolerant hardwood competition: Silvicultural efficacy of Chondrostereum purpureum and worker productivity in conifer plantations

“…These results confirm the tendency noted in the literature that the Betula genus is one of the most likely to react to an application of C. purpureum (Wall, 1990;Dumas et al, 1997;Jobidon, 1998;Harper et al, 1999;Vartiamä ki et al, 2009). Moreover, a North American listing showed that the birch family is the most frequently colonized by C. purpureum under natural conditions (Setliff, 2002). Nevertheless, the effects of the biological treatment on paper birch in our study are less important than those reported by Jobidon (1998), where the reduction in the number of living sprouts after two years was 10 times greater.…”

“…Pouzar fungus has been studied to uncover its ecology and pathology (de Jong, 2000;Ramsfield, 2006). This basidiomycetous white-rot fungus is naturally present in temperate North American forests, and is pathogenic to several hardwood species (Setliff, 2002). Indeed, the colonization of the fungus on a recent wound or cut allows it to grow through the xylem and causes necrosis of the cambium, decay, and even the death of the host (Wall, 1986).…”

Natural enemies of Japanese honeysuckle <i>Lonicera japonica</i> in New Zealand

“…The occurrence of C. purpureum on Japanese honeysuckle is a new host record for this fungus in New Zealand, and possibly also a new international record. The pathogen has been reported on other Lonicera species (Setcliff 2002), including the shrubby relative L. tatarica in New Zealand (Pennycook 989). This fungus is a widespread wound pathogen, commonly known as silver leaf disease, and is a plurivorous horticultural disease of economic importance.…”

Le gel de printemps et la pourriture fongique sont impliqués dans la suppression de la repousse des trembles rejetant après un nettoiement partiel dans des peuplements juvéniles

“…: Fr.) (Setliff, 2002), which may have played a role in the mortality of the stressed trees (Wall, 1991) at Lac La Biche. The drought in 2006 and ungulate herbivory likely exacerbated the impact of the frost and prevented recovery of the remaining regeneration, as mortality tends to increase when defoliation and drought occur sequentially (Hogg et al, 2005;Houston, 1992).…”