We have shown that Ca(II) ions, ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid, LaCl3, and six known calmodulin inhibitors shift the yeast-mycelium dimorphic potential of Ceratocystis ulmi. Our data are consistent with the conclusions that Ca(II)-calmodulin interaction is necessary for mycelial growth in C. ulmi and that the absence of this interaction leads to the yeast phase.

An investigation was carried out in some areas of Golestan Province including: Loveh forest, Soosara, Daland forest park, Tooskestan; Gilan Province including Siahkal and Asalem forests; Arasbaran and landscape of urban trees during 1999–2007. In this investigation, based on some morphological, physiological and molecular characteristics and also comparison with standard isolates two species Op...

The Chinese species Cryptococcus ulmi Tang & Hao is found to be distantly related to other sampled Cryptococcus species based on both molecular and morphological study. A new felt scale genus, Macroporicoccus Nan & Wu gen. n., is erected therefore for C. ulmi. The new genus differs from other eriococcid genera due to the presence of large simple pores, here referred to as macrodisc pores. The a...

AIMS   For Ophiostoma (Ceratocystis) ulmi, the ability to undergo morphological change is a crucial factor for its virulence. To gain an understanding of quorum-sensing activity in O. ulmi as it relates to yeast-mycelium dimorphism control, this study examines the effects of branched-chain amino acids as well as their fusel alcohols and fusel acids as quorum sensing molecules. METHODS AND RES...

We studied the inoculum size effect in Ceratocystis ulmi, the dimorphic fungus that causes Dutch elm disease. In a defined glucose-proline-salts medium, cells develop as budding yeasts when inoculated at > or = 10(6) spores per ml and as mycelia when inoculated at <10(6) spores per ml. The inoculum size effect was not influenced by inoculum spore type, age of the spores, temperature, pH, oxygen...

The root-knot nematode Meloidogyne ulmi is synonymised with Meloidogyne mali based on morphological and morphometric similarities, common hosts, as well as biochemical similarities at both protein and DNA levels. M. mali was first described in Japan on Malus prunifolia Borkh.; and M. ulmi in Italy on Ulmus chenmoui W.C. Cheng. Morphological and morphometric studies of their holo- and paratypes ...

Dutch elm disease is caused by the fungal pathogen Ophiostoma novo-ulmi which is transmitted by the native elm bark beetle, Hylurgopinus rufipes. We have found that four semiochemicals (the monoterpene (-)-beta-pinene and the sesquiterpenes (-)-alpha-cubebene, (+)-spiroaxa-5,7-diene and (+)-delta-cadinene) from diseased American elms, Ulmus americana, synergistically attract H. rufipes, and tha...