The taxonomy of Oculimacula, Rhynchosporium and Spermospora is re-evaluated, along with that of phylogenetically related genera. Isolates are identified using comparisons of DNA sequences of the internal transcribed spacer ribosomal RNA locus (ITS), partial translation elongation factor 1-alpha (tef1), actin (act), DNA-directed RNA polymerase II largest (rpb1) and second largest subunit (rpb2) genes, and the nuclear ribosomal large subunit (LSU), combined with their morphological characteristics. Oculimacula is restricted to two species, O. acuformis and O. yallundae, with O. aestiva placed in Cyphellophora, and O. anguioides accommodated in a new genus, Helgardiomyces. Rhynchosporium s. str. is restricted to species with 1-septate conidia and hooked apical beaks, while Rhynchobrunnera is introduced for species with 1–3-septate, straight conidia, lacking any apical beak. Rhynchosporium graminicola is proposed to replace the name R. commune applied to the barley scald pathogen based on nomenclatural priority. Spermospora is shown to be paraphyletic, representing Spermospora (type: S. subulata), with three new species, S. arrhenatheri, S. loliiphila and S. zeae, and Neospermospora gen. nov. (type: N. avenae). Ypsilina (type: Y. graminea), is shown to be monophyletic, but appears to be of minor importance on cereals. Finally, Vanderaaea gen. nov. (type: V. ammophilae), is introduced as a new coelomycetous fungus occurring on dead leaves of Ammophila arenaria.

27Currently, eight Phyllosticta species are known to be associated with Citrus hosts, 28 incorporating endophytic and pathogenic lifestyles. As sexual reproduction is a key factor 29 involved in host-interaction, it could be related to the differences in lifestyle. To evaluate this 30 hypothesis, we characterized the mating-type loci of six Citrus-associated Phyllosticta species 31 from whole genome assemblies. Mating-type genes are highly variable in their sequence 32 content, but the genomic locations and organization of the mating-type loci are conserved. 33Phyllosticta citriasiana, P. citribraziliensis and P. paracitricarpa are heterothallic, and P. 34 citrichinaensis was confirmed to be homothallic. In addition, the P. citrichinaensis MAT1-2 35 idiomorph occurs in a separate location from the mating-type locus. Ancestral state 36 reconstruction suggests that homothallism is the ancestral thallism state in Phyllosticta, with a 37 shift to heterothallism in Phyllosticta species that are pathogenic to Citrus. Moreover, the 38 homothallic strategies of P. capitalensis and P. citrichinaensis result from independent 39 evolutionary events. As the pathogenic species P. citriasiana, P. citricarpa and P. 40 paracitricarpa are heterothallic and incapable of selfing, disease management practices 41 focused in preventing the occurrence of sexual reproduction could assist in the control of 42Citrus Black Spot and Citrus Tan Spot diseases. This study emphasizes the importance of 43 studying Citrus-Phyllosticta interactions under evolutionary and genomic perspectives, as 44 these approaches can provide valuable information about the association between Phyllosticta 45 species and their hosts, and also serve as guidance for the improvement of disease 46 management practices. 47 48

Bells-of-Ireland (Moluccella laevis) (Lamiaceae) is an annual plant that is field planted in coastal California (Santa Cruz County) for commercial cutflower production. In 2001, a new leaf spot disease was found in these commercially grown cutflowers. The disease was most serious in the winter-grown crops in 2001 and 2002, with a few plantings having as much as 100% disease incidence. All other plantings that were surveyed during this time had at least 50% disease. Initial symptoms consisted of gray-green leaf spots. Spots were generally oval in shape, often delimited by the major leaf veins, and later turned tan. Lesions were apparent on both adaxial and abaxial sides of the leaves. A cercosporoid fungus having fasciculate conidiophores, which formed primarily on the abaxial leaf surface, was consistently associated with the spots. Based on morphology and its host, this fungus was initially considered to be Cercospora molucellae Bremer & Petr., which was previously reported on leaves of M. laevis in Turkey (1). However, sequence data obtained from the internal transcribed spacer region (ITS1, ITS2) and the 5.8S gene (STE-U 5110, 5111; GenBank Accession Nos. AY156918 and AY156919) indicated there were no base pair differences between the bells-of-Ireland isolates from California, our own reference isolates of C. apii, as well as GenBank sequences deposited as C. apii. Based on these data, the fungus was subsequently identified as C. apii sensu lato. Pathogenicity was confirmed by spraying a conidial suspension (1.0 × 105 conidia/ml) on leaves of potted bells-of-Ireland plants, incubating the plants in a dew chamber for 24 h, and maintaining them in a greenhouse (23 to 25°C). After 2 weeks, all inoculated plants developed leaf spots that were identical to those observed in the field. C. apii was again associated with all leaf spots. Control plants, which were treated with water, did not develop any symptoms. The test was repeated and the results were similar. To our knowledge this is the first report of C. apii as a pathogen of bells-of-Ireland in California. Reference: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Cornell University Press, Ithaca, New York, 1954.