Heteroconium sp. nov. from roots of Triticum aestivum in the United Kingdom.

Morphological and molecular studies led to the description of Heteroconium triticicola as a new species isolated from roots of wheat in the United Kingdom. The new fungus shares with H. citharexyli, the type species of Heteroconium Petrak, features such as superficial mycelium, macronematous, mononematous, unbranched, straight conidiophores, monoblastic, integrated, terminal, cylindrical conidiogenous cells, and catenate, dry, simple, cylindrical, obclavate, often pale brown, smooth, multiseptate conidia.

Microdochium triticicola sp. nov. from roots of Triticum aestivum in the United Kingdom.

Morphological and molecular studies led to the description of Microdochium triticicola as new species isolated from roots of wheat in the United Kingdom. The morphological features of all known Microdochium species are tabulated.

Phylogenetic relationships among Zygomycetes from soil based on ITS1/2 rDNA sequences.

New information was obtained on the phylogeny of Zygomycetes. PCR-RFLP analysis showed ITS1/2 rDNA to provide appropriate markers for genetic studies on Zygomycetes at the population and species levels. The use of several restriction enzymes allowed discrimination between genera and species of Mortierellales and Mucorales.

Variation in the effects of take-all disease on grain yield and quality of winter cereals in field experiments.

Relationships between take-all intensity and grain yield and quality were determined in field experiments on cereal crops using regression analyses, usually based on single-point disease assessments made during anthesis or grain-filling. Different amounts of take-all were achieved by different methods of applying inoculum artificially (to wheat only) or by using different cropping sequences (in wheat, triticale or barley) or sowing dates (wheat only) in crops with natural inoculum. Regressions of yield or thousand-grain weight on take-all intensity during grain filling were similar to those on accumulated disease (area under the disease progress curve) when these were compared in one of the wheat experiments.

Mode of action and pesticidal activity of the natural product dunnione and of some analogues.

This paper reports the investigation of the insecticidal and fungicidal activity of dunnione, a natural product obtained inadvertently as a by-product of a synthesis programme. Dunnione exhibits no insecticidal activity but has an unusually broad spectrum of antifungal activity. In vitro and in vivo (preventative) activities were comparable to those of several long-established fungicides (eg carbendazim).

Comparison of Gaeumannomyces- and Phialophora-like fungal pathogens from maize and other plants using DNA methods.

Several DNA-based techniques, developed for identifying and differentiating fungi in the Gaeumannomyces-Phialophora complex associated with take-all diseases of cereals and grasses, were used to compare fungi from maize. Maize isolates obtained as G. graminis (Sacc.