Cucumber breeding for spring film greenhouses for resistance to real powdery mildew

Relevance. Powdery mildew is one of the most common and harmful diseases of cucumber (Cucumis sativus L.) in open and protected ground. Moreover, in the closed ground, the harmfulness is higher than in the field. The yield of cucumber, due to the defeat of plants by powdery mildew, decreases by 30-50%, and in some cases by more than 70%. The creation of modern cucumber hybrids is impossible without the constant involvement in the breeding process of new sources of economically useful traits, including resistance to real powdery mildew. It is very important to combine in one line both a high degree of parthenocarpy, and the female type of flowering, and resistance to the most harmful diseases. We tried to solve this problem in our work.Materials and methods. The experience was laid in 2018-2022 in the Odintsovo district of the Moscow region on the basis of the head institution of the Federal State Budgetary Scientific Institution Federal Scientific Vegetable Center (FSBSI FSVC) in the conditions of a spring ground greenhouse of the Block type, on a natural infectious background. On the basis of the laboratory of breeding and seed production of pumpkin crops, 27 collectible and about 50 breeding samples of parthenocarpic cucumber were studied. The article presents an assessment of the resistance to this powdery mildew of 36 of the most aligned and most valuable cucumber breeding samples in terms of a complex of economically useful features. 2-3 families, 6 plants in each, were evaluated for each sample for 2 years. During the entire growing season, the intensity of powdery mildew damage was assessed on a four-point scale and the spread of the disease in %.Results. Among the collection samples of cucumber, on a natural infectious background, two hybrids of the agrofirm BEJO ZADEN B.V. were not affected by powdery mildew: Amur 1801 F1, Artist F1, a hybrid without a name of the agrofirm MONSANTO HOLLAND B.V., conventionally named – Semenis F1 and hybrid Kibria F1 of the agrofirm RIJK ZWAAN. To a small extent, less than one point, they were amazed: Orpheus F1, Merengue F1, Marinda F1, Masha F1, Othello F1, List F1, Adam F1, SV 4097 F1 and Krasotka F1. 11cucumber breeding samples selected in previous years of research on a complex of economically useful signs that were not affected by this disease during 2 years of research were identified. Work will continue to evaluate these lines for resistance to real powdery mildew on an artificial infectious background.