Diseases
Cucumis sativus L.
A fungal disease of cucumber caused by the obligate parasite Pseudoperonospora cubensis. It is characterized by the appearance of angular chlorotic spots on leaves and a distinctive layer of sporulation on the underside of the leaf.
In the reference 394 varieties crop Cucumber, where this is mentioned in the description.
The causative agent of the disease is the oomycete Pseudoperonospora cubensis, which exhibits high variability, leading to the emergence of new aggressive pathotypes and the overcoming of breeding resistance. Symptoms manifest as angular yellowish-green spots on the upper side of the leaf, which eventually turn brown and coalesce. A diagnostic feature under high humidity is the appearance of a grayish-violet or whitish layer of sporulation on the underside of the leaf blade.
In southern regions, the disease can occur in a latent form, manifesting as small chlorotic spots, which complicates visual diagnosis. The consequences of the infection include premature drying and shedding of leaves, deterioration of fruit marketability, and plant death. When cucumber plantings are affected, the fruits lose their taste qualities and characteristic coloration.
For breeding resistant varieties, Dm genetic markers are used, including the specific genes Dm1.1, Dm5.1, Dm5.3 and the non-specific STAYGREEN (CsSGR) gene. The historically significant dm-1 gene has ceased to provide protection due to the evolution of the pathogen. In the international classification of varieties, resistance to the pathogen is labeled with the Pcu code, divided into HR (high) and IR (intermediate) levels.
General information about the subject — on the page Downy mildew.
Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.
Cucumis sativus L. · Cucumber
Kondratenko Serhii Ivanovych, Pozniak Oleksandr Vasyl`ovych, Nesyn Volodymyr Mykolaiovych, Tkalych IUrii Vadymovych, Ptukha Nadiia Ivanivna,
Cucumis sativus L. · Cucumber
Henrikh IUst
Cucumis sativus L. · Cucumber
Yan Kulstra
Cucumis sativus L. · Cucumber
Petr Klapshte, Petr Horal, Yirzhi Horal,
Cucumis sativus L. · Cucumber
Dymchenko Tetiana Mykolaivna, Muzhylko Viktor Valentynovych,
Cucumis sativus L. · Cucumber
Prutenskaia Nataliia Oleksiivna, Shamshyna Anna Viacheslavovna, Portiankin Alieksiei IEvhenovych, Havrysh Serhii Fedorovych,
Cucumis sativus L. · Cucumber
Shevkunov Valerii Mykolaiovych, Prutens`ka Nataliia Oleksiivna, Shamshyna Anna Viacheslavovna, Portiankin Alieksiei IEvhenovych, Havrysh Serhii Fedorovych,
Cucumis sativus L. · Cucumber
Barbara Khrzhanovs`ka, Yezhy Matchak, Tereza Bartlomiieschak,
Cucumis sativus L. · Cucumber
GENESIS SEEDS LTD
Cucumis sativus L. · Cucumber
Milotay Peter, Hodozy Sandor
Cucumis sativus L. · Cucumber
Instytut ovochivnytstva i bashtannytstva Natsionalnoi akademii ahrarnykh nauk Ukrainy
Cucumis sativus L. · Cucumber
Ger Bimsdeboer
Cucumis sativus L. · Cucumber
Muzhylko Viktor Valentynovych, Neporozhnia IEvheniia Oleksiivna, Pluzhnikova Liudmyla IEhorivna, Lisitsina Rima Petrivna, Lisitsyn Volodymyr Mykolaiovych,
Cucumis sativus L. · Cucumber
Instytut Warzywnictwa im. Emila Chroboczka
Cucumis sativus L. · Cucumber
Yost van den Eiden
Cucumis sativus L. · Cucumber
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Cucumis sativus L. · Cucumber
Kyrylov Mykhailo Ivanovych, Dubinin Serhii Volodymyrovych,
Cucumis sativus L. · Cucumber
Bratchenko Praskov'ia Ivanivna, Horhan Nadiia Oleksandrivna, Nabokova Liudmyla Oleksiivna,
Cucumis sativus L. · Cucumber
Seminis Vegetable Seeds
Cucumis sativus L. · Cucumber
Kyrylov Mykhailo Ivanovych, Dubinin Serhii Volodymyrovych,
Cucumis sativus L. · Cucumber
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Cucumis sativus L. · Cucumber
Andzhei Rostvorovskyi
Cucumis sativus L. · Cucumber
Hary Bessels
Cucumis sativus L. · Cucumber
Kyrylov Mykhailo Ivanovych, Dubinin Serhii Volodymyrovych,