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ABSTRACTSphaerodes mycoparasiticaVuj. is a Fusarium-specific mycoparasite. Some recent discoveries recognize its biotrophic polyphagous lifestyle as an interesting biocontrol property against a broad spectrum of mycotoxigenic Fusariumhosts. Secondary metabolites such as mycotoxins produced by Fusariumspp. may play an important role in the signaling process, allowing an early mycoparasite-host recognition. A multiple-paper-disc assay has been conducted to test S. mycoparasiticahyphal adaptability to filtrates of 12 Fusariumspp. This study shows that shifts of adapted and nonadapted hyphal migration towards different Fusarium-host filtrates may partly explain S. mycoparasiticapolyphagous lifestyle, and its adaptability depending on host preference or compatibility. In terms of host compatibility, the current findings suggest that S. mycoparasiticatends to prefer native Fusariumhosts more related to its origin and propose that the mycoparasite could possess diphasic interactions such as biotrophic-attraction and antagonistic-inhibition relationships based on relative radial growth. This implies that the mycoparasite may use a group of mycotoxins produced by specific Fusariumspp. as an adaptive selective mechanism that facilitates a parasite-host recognition and further successful mycoparasitism. In particular, relative polarity or hydrophilicity/hydrophobicity of mycotoxins may be related to solubility and absorption properties in hyphae of the mycoparasite. Taken together, the studies of host compatibility and adaptability depending on host filtrates will aid in understanding complex mechanisms of S. mycoparasitica, as a promising model organism for a specific biotrophic mycoparasite to enhance and improve biocontrol efficacy against Fusaria.

Willow (Salixspp.) short‐rotation coppice (SRC) systems are becoming an attractive practice because they are a sustainable system fulfilling multiple ecological objectives with significant environmental benefits. A sustainable supply of bioenergy feedstock can be produced by willow on marginal land using well‐adapted or tolerant cultivars. Across Canada and the northern United States, there are millions of hectares of available degraded land that have the potential for willow SRC biomass production, with a C sequestration potential capable of offsetting appreciable amounts of anthropogenic greenhouse gas emissions. A fundamental question concerning sustainable SRC willow yields was whether long‐term soil productivity is maintained within a multi‐rotation SRC system, given the rapid growth rate and associated nutrient exports offsite when harvesting the willow biomass after repeated short rotations. Based on early results from the first willow SRC rotation, it was found that willow systems have relatively low nutrient demands, with minimal nutrient outputs other than in the harvested biomass. Our overall aim was to summarize the literature and present findings and data from ongoing research trials across Canada and the northern United States examining willow SRC system establishment and viability. The research areas of interest are the crop production of willow SRC systems, above‐ and belowground biomass dynamics and the C budget, comprehensive soil–willow system nutrient budgets, and soil nutrient amendments (via fertilization) in willow SRC systems. Areas of existing research gaps were also identified for the Canadian context.

Sphaerodes quadrangularisGarcía, Stchigel & Guarro was shown to be a facultative contact biotrophic mycoparasite of Fusarium avenaceum(Fr.) Sacc. (teleomorph: Gibberella avenaceaCooke) that established an intimate relationship with its host by producing hook-shaped and clamp-like attachment structures that appeared to derive nutrients and other essential factors from living host cells. The contact cells of the mycoparasite surrounded and envelop host hyphae and, although they do not appear to penetrate the host, the parasitized hyphae were significantly smaller than unparasitized controls. Sphaerodes quadrangularisdid not form specialized attachment structures when cultured together with strains representing F. oxysporumand F. graminearum, indicating some degree of host specificity in the parasite.

Pseudorobillarda monicasp. nov. is described and illustrated. The endophyte was isolated from living leaves and bark of twigs of a Thuja occidentalisbonsai (>90 years old) at the Montréal Botanical Garden and ornamental trees in Montréal urban plantations. This pycnidial fungus is typical of the genus in morphology but clearly differs from other species in Pseudorobillardaby the distinct size of the conidiomata and the shape and size of conidia and paraphyses. Its taxonomic placement is discussed and a key to the species of Pseudorobillardais provided.

AbstractA new species of Coelomycete, Leptomelanconium abietis, is described and illustrated from chlorotic and necrotic needles of Abies balsamea.This fungus is typical of the genus in morphology and ecology, but clearly different from other known species in Leptomelanconiumby host, distinct size of conidiomata, and shape and size of conidia. Its taxonomic placement and relation to other species in this genus and the genus Gloeocoryneumare given.

AbstractA new hyphomycete Phialocephala victoriniisp. nov. is an endophyte isolated from living roots of the terrestrial orchid Cypripedium parviflorum. Phialocephala victoriniiis typical of the genus in morphology and ecology, but clearly different from other known species of Phialocephalain having characters not previously described: slow growing colony, dark brown to golden brown on malt agar, and sporulating readily on corn meal agar, bearing regular conidiophores, sterile lateral protuberances present on hyphae in fertile region and not on the conidiophores, stipe base and apex subhyaline, collarettes extremely expanded, and conidia of two kinds: dark brown, obovoid or lunate, and light brown, allantoid conidia. Its sensitivity to cycloheximide suggests an affinity inside Phialocephalaand no teleomorph connection with Ophiostoma.The taxonomic placement of the new species and a key to the members of Phialocephalaare given.

AbstractPolynema muirii sp. nov. is described and illustrated from Fagus grandifoliacollected in the Muir's Wood, Québec, Canada. It is compared with known Polynemaspecies. This is the second report of a species of Polynemafrom North America.

Choanatiara lunata is a coelomycetous fungus producing conidia with funnel-shaped appendages. The species was originally reported on fallen needles of Pinus resinosa and P. strobus in Ontario, Canada. Our systematic work on coelomycetes in Pinus spp. was carried out on 29 different pine hosts (species, varieties, forms or cultivars) at the arboretum of the Montreal Botanical Garden. Choanatiara lunata was isolated (on PDA, MA, CMA) from 9 (31%) of the pine hosts investigated. From those, four hosts are species indigenous to North America: P. albicaulis (subgenus Haploxylon), P. resinosa, P. ponderosa, and P. jeffreyi (subgenus Diploxylon). The other five hosts are pines exotic to North America. Three are indigenous to Europe: P. nigra 'Laricio', P. nigra 'Nigra', and P. nigra 'Pallasiana' (subgenus Diploxylon), and two are indigenous to East Asia: P. densiflora and P. tabulaeformis (subgenus Diploxylon). Except for P. resinosa, these are all new hosts for this fungus. The fungus was associated with symptoms of summer needle necrosis in the crown. For the first time, the cultural characteristics of the fungus are given, and the morphology of C. lunata described in this work was compared to the one reported by Nag Raj (1993).