First Report of Golovinomyces biocellatus Causing Powdery Mildew on Spearmint (Mentha spicata) in Mexico

In 1997 and 1998, the white fungal growth of a powdery mildew was observed on leaves and stems of both nursery and landscape spearmint (Mentha spicata) growing in coastal California (Monterey County). Mycelia were conspicuous, amphigenous, and epiphytic with indistinct to nipple-shaped appressoria. Conidiophore foot cells were cylindrical, straight, nonconstricted at the base, 61 to 92 μm × 11 to 14 μm in size, and were followed by 1 to 3 cells. Doliiform conidia, which were borne in chains of at least 3 to 5 conidia, measured 28 to 33 μm × 17 to 22 μm. Catenate conidia had sinuate edge lines. Conidia lacked fibrosin bodies. Upon germination, conidia produced germ tubes that were mostly apically inserted and ended in club-shaped appressoria, which fit Braun's Cichoracearum-type of conidial germination (1). Cleistothecia were not observed. Based on these features, the pathogen was identified as Erysiphe orontii Cast. (1). Pathogenicity was demonstrated by gently pressing diseased leaves onto leaves of potted spearmint, incubating plants in a humidity chamber for 48 h, then maintaining plants in a greenhouse. The powdery mildew that later developed was morphologically identical to the original isolates. While powdery mildew on spearmint has been observed previously in the state, this is the first report of the disease and first characterization of the pathogen for California. Reference: (1) U. Braun. Beih. Nova Hedwigia 89:1, 1987.

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First report of Podosphaera fusca causing powdery mildew on asparagus bean in Taiwan

Journal of Plant Pathology ◽

10.1007/s42161-021-00862-w ◽

2021 ◽

Author(s):

Yi-Ting Xiao ◽

Chao-Jen Wang ◽

Tung-Chin Huang ◽

Yuan-Min Shen

Keyword(s):

Powdery Mildew ◽

First Report ◽

Asparagus Bean ◽

Podosphaera Fusca

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First Report of Powdery Mildew of Kalanchoe blossfeldiana caused by Sphaerotheca fuliginea (Podosphaera fuliginea) in the Pacific Northwest

Plant Health Progress ◽

10.1094/php-2003-0417-02-hn ◽

2003 ◽

Vol 4 (1) ◽

pp. 39

Author(s):

Dean A. Glawe ◽

Rita Hummel ◽

Grace Jack

Keyword(s):

Powdery Mildew ◽

Pacific Northwest ◽

Sphaerotheca Fuliginea ◽

First Report ◽

Major Disease ◽

The Pacific ◽

Kalanchoe Blossfeldiana ◽

Extension Center ◽

Kalanchoë Blossfeldiana

Kalanchoe blossfeldiana Poelln. is a common ornamental houseplant. Although powdery mildew is a major disease of this species, there are no published reports of it in the Pacific Northwest. In August, 2002, powdery mildew was observed on six indoor K. blossfeldiana plants in an office and adjacent laboratory at the Puyallup Research and Extension Center. Accepted for publication 25 March 2003. Published 17 April 2003.

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First report of Podosphaera pannosa causing powdery mildew on Rosa chinensis in Brazil

Journal of Plant Pathology ◽

10.1007/s42161-020-00513-6 ◽

2020 ◽

Vol 102 (3) ◽

pp. 933-933

Author(s):

Wéverson Lima Fonseca ◽

José Emilson Cardoso ◽

Cristiano Souza Lima ◽

Francisco Marto Pinto Viana ◽

Márcio Akio Ootani ◽

...

Keyword(s):

Powdery Mildew ◽

First Report ◽

Rosa Chinensis

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Further Support of Conspecificity of Oak and Mango Powdery Mildew and First Report of Erysiphe quercicola and Erysiphe alphitoides on Mango in Mainland Europe

Plant Disease ◽

10.1094/pdis-01-17-0116-re ◽

2017 ◽

Vol 101 (7) ◽

pp. 1086-1093 ◽

Cited By ~ 8

Author(s):

Marie-Laure Desprez-Loustau ◽

Marie Massot ◽

Nicolas Feau ◽

Tania Fort ◽

Antonio de Vicente ◽

...

Keyword(s):

Powdery Mildew ◽

Host Range ◽

Molecular Mechanisms ◽

Single Copy ◽

Broad Host Range ◽

First Report ◽

Erysiphe Quercicola ◽

Powdery Mildews ◽

Mango Leaves ◽

Practical Implications

Mango leaves and inflorescences infected by powdery mildew in southern Spain were analyzed using multigene sequencing (ITS + 4 single-copy coding genes) to identify the causal agent. Erysiphe quercicola was detected in 97% out of 140 samples, collected in six different orchards in the Malaga region. Among these, a small proportion also yielded E. alphitoides (8% of all samples) and E. alphitoides was found alone in 3% of samples. A phylogenetic approach was completed by cross inoculations between oak and mango, which led to typical symptoms, supporting the conspecificity of oak and mango powdery mildews. To our knowledge, this is the first report of E. quercicola and E. alphitoides causing powdery mildew on mango trees in mainland Spain, and thus mainland Europe, based on unequivocal phylogenetic and biological evidence. Our study thus confirmed the broad host range of both E. quercicola and E. alphitoides. These results have practical implications in terms of the demonstrated ability for host range expansion in powdery mildews. They also open interesting prospects to the elucidation of molecular mechanisms underlying the ability to infect single versus multiple and unrelated host plants since these two closely related powdery mildew species belong to a small clade with both generalist and specialist powdery mildews.

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First Report of Powdery Mildew of Lycium chinense (Chinese Matrimony Vine) Caused by Arthrocladiella mougeotii in the Pacific Northwest

Plant Health Progress ◽

10.1094/php-2004-1208-01-hn ◽

2004 ◽

Vol 5 (1) ◽

pp. 16

Author(s):

Dean A. Glawe

Keyword(s):

North America ◽

Powdery Mildew ◽

Medicinal Plant ◽

Pacific Northwest ◽

Morphological Features ◽

Lycium Chinense ◽

First Report ◽

Landscape Plant ◽

The Pacific ◽

Plant Grown

Chinese matrimony-vine (Lycium chinense Mill.) is a traditional medicinal plant grown in China and used as a perennial landscape plant in North America. This report documents the presence of powdery mildew on L. chinense in the Pacific Northwest and describes and illustrates morphological features of the causal agent. It appears to be the first report of a powdery mildew caused by Arthrocladiella in the Pacific Northwest. Accepted for publication 10 November 2004. Published 8 December 2004.

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