Evaluation of promising cucumber lines of the parthenocarpic type for resistance to false powdery mildew in open ground conditions of the Moscow region

Relevance. False powdery mildew (peronosporosis) (the causative agent is Pseudoperonospora cubensis (Berk. et Curt.) Rostow.) – the most harmful disease on cucumber in the open ground, spring film and winter greenhouses in the autumn crop turnover. In the laboratory of breeding and seed production of pumpkin crops of All-Russian Research Institute of Vegetable Breeding and Seed Production, currently FSBSI FSVC, continuous work is underway to create varieties and hybrids of cucumber resistant to this disease. To create new competitive hybrids of cucumber of the parthenocarpic type, a lot of work was done on the selection of parental forms that differ in a complex of economically useful signs, including tolerance to false powdery mildew.Results. During 2 years of research, in the open ground conditions of the Moscow region, on a natural infectious background, the lines of parthenocarpic cucumber most resistant to false powdery mildew were selected: Pr. F6 1, 24-905 RZ F4-5, Excel. F5 b/w 1, (Hac. x Hub.) F4. During the second (30.08.) and third (08.09) counts, in both years of research, according to the lesion score, they were at the level of a stable standard - the Surazhevsky variety. In 2022, in the conditions of unheated spring greenhouses of Primorsky region, two hybrid combinations of 24-905RZ F4 x Pr. F11 and Kar. F6 x Pr. F11 were distinguished for resistance to peronospore. At the end of August, they were struck by 0.5 and 0.8 points, respectively, less than the standard hybrid German F1. The resulting hybrid combinations were obtained with the participation of cucumber lines of the parthenocarpic type, the most tolerant to false powdery mildew in the open ground conditions of the Moscow region in 2022 and 2023. This indicates that the isolated samples can serve as gene sources of resistance to false powdery mildew.