Based on nuclear encoded small subunit (18S) rDNA sequences, a taxonomic reappraisal of Graphium (anamorphic fungi) was undertaken using neighbour-joining (NJ) and fast DNA maximum likelihood (fastDNAml) methods and compared with traditional classifications. In common with Graphium putredinis, Graphium penicillioides (the lectotype species) was found to be related to the Microascales, not the Ophiostomatales as previously believed. Both species might be heterogenous and should be treated as species aggregates. The representative mode of conidiogenesis for these two species was nodular-annellidic, rather than the dense-annellidic mode characteristic of the synnematous ophiostomatalean anamorphs. Graphium is emended to be restricted to G. penicillioides, G. putredinis, and related synnematous anamorphs of Petriella and Pseudallescheria, and a nomenclator for the nine species presently accepted in Graphium is presented. Pesotum, originally characterized mainly by sympodial conidiogenesis, is emended to include synnematous anamorphs of Ophiostoma species formerly included in a variety of genera with sympodial to dense-annellidic conidiogenesis. Eight new combinations in Pesotum are included in a nomenclator for the 26 species currently known. Three new combinations from Ceratocystis to Ophiostoma are proposed for species with Pesotum anamorphs. The holomorph of Graphium calicioides has affinities to the black yeasts and should be classified in the Chaetothyriales. However, the critical morphological, loculoascomycetous characters of the teleomorph are not completely documented. Interpreted from the molecular context, the morphological similarities between these three groups of anamorphs are homoplasies and examples of convergent evolution.Key words: Chaetothyriales, Graphium, Microascales, Ophiostomatales, Pesotum, 18S (SSU) rDNA sequences.

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The reactions of the triplet state of 4-nitroquinoline 1-oxide (4NQO) with a series of amino acids and some proteins in aqueous solutions have been studied by using a laser flash technique. Only tryptophan (TrpH) and tyrosine (TyrOH) among a series of amino acids quench the triplet 4NQO (T4NQO) at a diffusion-controlled rate. Lysozyme, ribonuclease, and histone, which contain TrpH and/or TyrOH residues, had rate constants comparable to those of TrpH and TyrOH. The formation of the H adduct of 4NQO (4NQOH*), which may be produced by the reaction of 4NQO" with water, was confirmed from the transient absorption spectra for 4NQO solutions containing these quenchers. The transient absorption spectra observed for TrpH and TyrOH solutions elucidated the formation of the deprotonated forms of TrpH+ and TyrOH"1" (Trp* and TyrO') together with 4NQOH*. The result demonstrates that the electron transfer from TrpH or TyrOH to T4NQO occurs in the triplet quenching by TrpH or TyrOH. Since the almost same transient spectra as Trp* and TyrO* were observed for lysozyme and ribonuclease solutions, respectively, TrpH residues on lysozyme and TyrOH residues on ribonuclease are main quenching sites, where electron transfer and deprotonation occur. The quantum yields of T4NQO, 4NQOH*, Trp*, and TyrO" produced by the excitation of the 4NQO solution containing TrpH or TyrOH with a 355-nm light pulse were determined to be 0.46, 0.47, 0.41, and 0.41, respectively. The result shows that the efficiency in electron transfer from TrpH or TyrOH to T4NQO is ~90%. For the reaction of T4NQO with methionine, arginine, histidine, lysozyme, or ribonuclease, the efficiency in electron transfer was also estimated to be nearly equal to that for the reaction with TrpH or TyrOH.

The partial nucleotide sequences of 18S ribosomal RNA (positions 1451 to 1618 in Saccharomyces cerevisiae) of 48 strains representing 46 species of ballistosporous yeasts and a related genus were determined by dideoxy sequencing with reverse transcriptase. The sequence data were analyzed by neighbor-joining method and several unrooted phylogenetic trees were drawn. Ballistosporous yeast species were separated into two groups: a group of xylose-containing species and a group of xylose-lacking species.