Fungi colonizing cysts of Heterodera glycines

Includes bibliographical references (p. 36-37)

First report of white rust of Aurinia saxatilis (Alyssum saxatile) caused by Albugo candida in Washington state

Albugo candida, cause of white rust, is reported to occur on Aurinia saxatilis (synonym: Alyssum saxatile). The pathogen was found on landscape plants growing in a private garden in Seattle, WA where it over-wintered on infected leaves. This appears to be the first report of A. candida on this host in the USA

Synopsis of genera of Erysiphales (powdery mildew fungi) occurring in the Pacific Northwest

The Erysiphales (powdery mildew fungi) are Ascomycetes of major economic significance. Recent taxonomic research, mostly in Asia and Europe, has produced major changes in genus concepts complicating identification of powdery mildew fungi and communication about the diseases they cause. This paper provides a summary of genus concepts applicable to powdery mildew fungi known in the Pacific Northwest, as well as dichotomous keys based on both anamorphic and teleomorphic features, and brief summaries of diagnostic features. Salient morphological features are illustrated with photographs made from recent collections from the region. The following genera are included: Arthrocladiella, Blumeria, Erysiphe, Golovinomyces, Leveillula, Neoerysiphe,Phyllactinia, Podosphaera, and Sawadaea. Consistent with modern systems of classification, Microsphaera, Uncinula, andUncinuliella are subsumed within the modern concept of Erysiphe, and Sphaerotheca species are included in Podosphaera

First report of powdery mildew of Lactuca sativa (garden lettuce) caused by Golovinomyces cichoracearum in the Pacific Northwest

During continuing surveys for powdery mildew fungi in the Pacific Northwest, Golovinomyces cichoracearum was found on Lactuca sativa (garden lettuce) in Seattle, King County, Washington. This paper documents the occurrence of G. cichoracearum on L. sativain the Pacific Northwest with illustrations of the fungus from fresh material

Powdery mildews on weeds in the Pacific Northwest: a miscellany of new records

Erysiphe polygoni on Rumex crispus, documented previously in California, is reported for the first time in the Pacific Northwest. Podosphaera (Sphaerotheca) fusca is reported in the Pacific Northwest for the first time on Taraxacum laevigatum, a host record documented previously in Europe. New host records for Idaho are Golovinomyces sordidus on Plantago major, Erysiphe convolvuli on Convolulus arvensus, and Podosphaera ( Sphaerotheca) aphanis on Geum macrophyllum. Golovinomyces (Erysiphe) cichoracearum on Cirsium arvense is reported for the first time in Washington

New North American Records of Anamorphic Powdery Mildew Fungi (Erysiphales) Parasitizing Species of Leucothoë and Limnanthes

This paper documents the presence of two species of Erysiphales previously unreported in North America. The fungi were encountered on greenhouse-grown host plants in Oregon during the 2006 growing season. Oidium ericinum was found on potted plants of Leucothoë axillaris (Ericaceae) grown at a wholesale nursery where it resulted in a substantial financial loss to the grower.Oidium limnanthis was found on potted plants of Limnanthes alba (Limnanthaceae) where it was associated with premature senescence of plants and reduced seed production. This appears to be the first record of a powdery mildew fungus parasitizing a member of the Limnanthaceae in North America. Both species are described and illustrated

New North American host records for Seifertia azaleae, cause of Rhododendron bud blight disease

Seifertia azaleae, cause of Rhododendron bud blight disease, is reported to occur on Rhododendron hemsleyanum, Rhododendron ponticum, and several named hybrids in western Washington State. This appears to be the first report of S. azaleaeon these hosts in North America

First Report of Erysiphe (Uncinuliella) flexuosa in western North America

Erysiphe flexuosa, a powdery mildew parasite of Aesculus species, is believed to have originated in North America where distribution records were confined to regions east of the Rocky Mountains. The fungus recently was found in eastern Washington State and northern Idaho. The fungus can be distinguished readily from other powdery mildews attacking Aesculus species by the presence of two distinctive kinds of chasmothecial appendages. Consistent with previous reports on similar species, observations determined that subulate appendages formed first, on dorsal sides of chasmothecia. The longer, uncinate appendages formed equatorially during later chasmothecial maturation. There are no Aesculus species native to northwest North America that could have hosted an undetected population of the fungus. It appears likely that E. flexuosa became established relatively recently in the inland Pacific Northwest, possibly being introduced on infected host material, similar to the situation in Europe where several reports documented the presence of the fungus beginning in 2000

Characterization of Seuratia millardetii on Camellia species and in artificial culture

A sooty mold-like disease of Camellia species is observed frequently in the Pacific Northwest but the identity of the causal organism has not been reported. To clarify taxonomy of the fungus associated with the disorder, affected Camellia leaves were collected from locations in Seattle, WA, and from the Camellia collection of the Washington Park Arboretum, University of Washington. The fungus on affected leaves was determined to be Seuratia millardetii (anamorph: Atichia glomerulosa ), a member of the Myriangiales sensu Barr known previously from conifer species in the region. Fungal colonies ranged from less than 0.1 mm to 5 mm in diameter, and were cushion-shaped to lobed. Colonies consisted of a peridium of melanized cells containing enclosing globose, hyaline cells in a gelatinous matrix; hyphae were lacking. Dimorphic macroconidia and microconidia (determined in this study to be phialospores) typical of A. glomerulosa were observed. The teleomorph included bitunicate asci and ascospores typical of S. millardetii. Observation with SEM confirmed that colonies grew superficially on leaves without penetrating them. Colonies in culture resembled those on host leaves, produced dimorphic macroconidia, but grew indeterminately to become several cm across. The fungus was observed on several named cultivars of C. japonica, C. sasanqua, and C. x williamsii. Although known previously from a wide variety of angiosperm and conifer hosts, this is the first time S. millardetii has been reported on Camellia spp. This is also the first report of the teleomorph of this fungus in the Pacific Northwest, and the first description of the fungus in artificial culture

A Festschrift in Honor of Professor Jack D. Rogers

Introduction to this Festschrift in Honor of Professor Jack D. Rogers