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
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Cucumis sativus L. · Cucumber
Dutch American Plantbreeders Corp.
Cucumis sativus L. · Cucumber
Lim Sang Hwa
Cucumis sativus L. · Cucumber
Yost van den Eiden
Cucumis sativus L. · Cucumber
Vovk Zhanna Mykolaivna
Cucumis sativus L. · Cucumber
Gari Besels
Cucumis sativus L. · Cucumber
Shevchenko Igor
Cucumis sativus L. · Cucumber
Bartkovska Zofiia, Drozhdzhevska Krystyna, Lakovska-Ryk El`zhbeta, Dorukhovski Rokh,
Cucumis sativus L. · Cucumber
Dymchenko Tetiana Mykolaivna, Muzhylko Viktor Valentynovych,
Cucumis sativus L. · Cucumber
Suvorova Tetiana IAkovlivna, Khomchenko Nina Mykolaivna, Shevkunov Valerii Mykolaiovych, Shamshyna Hanna Viacheslavivna, Portiankin Oleksii IEvhenovych, Havrysh Serhii Fedorovych,
Cucumis sativus L. · Cucumber
Pozniak Oleksandr Vasyl`ovych, Pluzhnikova Liudmyla IEhorivna, Kryvets` Dmytrii Olehovych, Lisitsyn Volodymyr Mykolaiovych, Bakumenko Nadiia Vasylivna, Petrenko Mariia Petrivna,