Review
Horticulture
Zhanbin Sun, Shufan Yu, Yafeng Hu, Yanchen Wen
Summary: This review provides an overview of the biocontrol strategies for cucumber downy mildew (CDM). It introduces the biological characteristics of Pseudoperonospora cubensis and recommends screening strategies for biocontrol agents. The review also summarizes the current biocontrol agents with the ability to control CDM, discusses their control characteristics and potential mechanisms, and provides suggestions for future research.
Article
Plant Sciences
Dor Barnea, Uri Yermiyahu, Dalia Rav-David, Yigal Elad
Summary: It was found that increasing nitrogen concentrations in irrigation water increased the severity of cucumber downy mildew, while increasing potassium or calcium concentrations gradually increased the severity. On the other hand, increasing phosphorus and magnesium concentrations in irrigation water decreased the severity. Spraying salts with chloride and sulfate anions suppressed the disease in most cases, and there was a negative relationship between salt and anion concentrations and disease severity. Spraying with specific salts and monopotassium phosphate reduced downy mildew under commercial conditions.
Article
Plant Sciences
A. Rahman, J. R. Standish, K. N. D'Arcangelo, L. M. Quesada-Ocampo
Summary: Pseudoperonospora cubensis is the cause of cucurbit downy mildew, with annual epidemics in the United States due to windborne sporangia traveling long distances and surviving prolonged exposure to sunlight. A multiplex quantitative PCR assay has been developed to detect the pathogen early on and improve disease management.
Article
Plant Sciences
Savithri Purayannur, David H. Gent, Timothy D. Miles, Sebastjan Radisek, Lina M. Quesada-Ocampo
Summary: Pseudoperonospora humuli is a destructive oomycete causing downy mildew in cultivated hops. The pathogen overwinters in plants, leading to significant crop loss, and is managed by sanitation practices, resistant cultivars, and fungicides. Future disease management may involve genomics and effector discovery.
MOLECULAR PLANT PATHOLOGY
(2021)
Article
Plant Sciences
Nagaraju Jhansirani, Venkatappa Devappa, Chittarada Gopal Sangeetha, Shankarappa Sridhara, Kodegandlu Subbanna Shankarappa, Mooventhiran Mohanraj
Summary: Through homology modeling and docking analysis, it was found that phytochemicals from cucumber, antimicrobial compounds from botanical sources, and chemically synthesized compounds can interact with proteins linked to cucumber downy mildew, showing potential antifungal activity.
Article
Agronomy
Dong Jae Lee, Jae Sung Lee, Young-Joon Choi
Summary: Pseudoperonospora cubensis was found causing downy mildew on oriental pickling melon in Korea for the first time, with two distinct phylogenetic clades detected. Urgent phytosanitary measures, including rapid diagnosis and effective control management, are required due to high incidence and susceptibility.
Article
Biochemistry & Molecular Biology
Bin Wang, Zhaolin Xue, Jie Lan, Mingyou Sun, Qin Sun, Zhongqiao Huang, Can Zhang, Xili Liu
Summary: Y18501 is a new oxysterol-binding protein inhibitor that has similar structure to oxathiapiprolin. It exhibits strong inhibitory activities against Phytophthora spp. and Pseudoperonospora cubensis, with EC50 ranging from 0.0005 to 0.0046 μg/mL. Y18501 has good control efficacy on cucumber downy mildew, effectively inhibits different development stages of P. cubensis, and shows excellent protective and curative activities against the pathogen. It also has acropetal systemic mobility in cucumber leaves and can be taken up and translocated more effectively from the lower leaves to the upper leaves compared to from the roots. The simultaneous application of Y18501 and chlorothalonil can significantly enhance the inhibition of P. cubensis.
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
(2023)
Article
Agronomy
Osama O. Atallah, Ali Osman, Mohamed A. S. Ali, Mahmoud Sitohy
Summary: The study showed that soybean beta-conglycinin and catfish p22 glycoproteins have significant antifungal activity against P. cubensis, comparable to highly efficient chemical fungicides. Chickpea vicilin and duck egg ovomucin were less efficient. All tested glycoproteins provided full protection for newly emerged cucumber leaves.
PEST MANAGEMENT SCIENCE
(2021)
Article
Plant Sciences
K. N. D'Arcangelo, E. C. Wallace, T. D. Miles, L. M. Quesada-Ocampo
Summary: Since its reemergence in 2004, Pseudoperonospora cubensis (CDM) has exhibited changes in fungicide sensitivity, with frequent applications needed to combat the disease. Fungicides such as carboxylic acid amides (CAA) and quinone outside inhibitors (QoI) are used, but resistance has developed due to single nucleotide polymorphism (SNP) mutations. This study found that CAA resistance is more prevalent in clade 2 isolates, while QoI resistance is widespread across both clades. The occurrence of fungicide resistance mutations in specific clades highlights the importance of understanding population dynamics for effective fungicide programs.
Article
Plant Sciences
Julian C. Bello, Douglas S. Higgins, Monique L. Sakalidis, Lina M. Quesada-Ocampo, Frank Martin, Mary K. Hausbeck
Summary: This study improved the detection method of cucurbit downy mildew by using qPCR, allowing for accurate prediction of disease risk before its occurrence, which is applicable for cucumber crop protection in Michigan.
Article
Microbiology
Marcin Nowicki, Denita Hadziabdic, Robert N. Trigiano, Sarah L. Boggess, Loukas Kanetis, Phillip A. Wadl, Peter S. Ojiambo, Marc A. Cubeta, Otmar Spring, Marco Thines, Fabian Runge, Brian E. Scheffler
Summary: This study used microsatellites to analyze the genetic diversity and spatial distribution of P. cubensis and P. humuli, revealing the genome-scale organizational relationship between the two pathogens. The results provided strong evidence supporting the hypothesis that they are distinct species, with potential further speciation within the P. cubensis complex.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Plant Sciences
H. N. Lavanya, B. Varalakshmi, M. Pitchaimuthu, S. Sriram, R. Venugopalan, G. M. Sandeep Kumar
Summary: Ten varieties and thirteen advanced breeding lines of ridge gourd were screened for downy mildew resistance, and ten moderately resistant lines were identified. Among them, IIHR-DMR-18-4-4 and IIHR-DMR-18-65-1 showed the best resistance with disease indexes of 23.46 and 24.03, respectively. These moderately resistant lines exhibited slow disease progression and can be used for breeding resistant ridge gourd cultivars with desirable horticultural traits.
AUSTRALASIAN PLANT PATHOLOGY
(2023)
Article
Plant Sciences
Isaack Kikway, Anthony P. Keinath, Peter S. Ojiambo
Summary: Cucurbit downy mildew, caused by Pseudoperonospora cubensis, is a significant disease for cucurbits worldwide. Alternating fungicides with different modes of action is recommended to prevent the development of resistance. This study investigated the shifts in sensitivity profiles of P. cubensis isolates during the growing season in response to various fungicides.
Article
Microbiology
Chandramani Raj, Rajan Sharma
Summary: Sclerospora graminicola exhibits heterothallic and homothallic mating types, and this study reveals the importance of sexual reproduction in the genetic recombination of the pathogen.
Article
Agronomy
Glicia Silva de Moraes, Juliana Ferreira de Mello, Amanda Cupertino de Queiroz Brito, Ailton Reis, Sami Jorge Michereff, Andre Angelo Medeiros Gomes, Marcos Paz Saraiva Camara, Janiele Cassia Barbosa Vieira, Cristina Maria de Souza-Motta, Alexandre Reis Machado
Summary: The objective of this study was to determine the phylogeny of Pseudoperonospora species causing downy mildew in cucurbits in different regions of Brazil. Phylogenetic analysis of DNA extracted from diseased leaves revealed that distinct lineages of P. cubensis are responsible for downy mildew of cucurbits in Brazil.
EUROPEAN JOURNAL OF PLANT PATHOLOGY
(2023)
