Selection of cucumber for parthenocarpy for spring greenhouses

Scientific relevance. Currently, in the protected ground, the main areas are occupied by parthenocarpic hybrids of cucumber of foreign origin. Therefore, the selection of domestic cucumber hybrids of the parthenocarpic type is very relevant. Material and conditions. The experience was laid in 2018-2022 in the Odintsovo district of the Moscow region in the conditions of a spring film ground greenhouse of the "Block" type on the basis of the head institution of the FSBSI FSVC. Agrotechnics of cultivation is generally accepted for the conditions of spring film greenhouses. In breeding nurseries where there were no bees, the degree of parthenocarpy was determined as the ratio of the fruit set to the number of female flowers formed on the plant, as a percentage. The records were carried out from the 5th to the 20th node inclusive, only on plants of the female type of flowering. On the basis of the laboratory of breeding and seed production of pumpkin crops, 27 collectible and more than 50 breeding samples of parthenocarpic cucumber were studied. Results. During three years of research, 7 hybrids of cucumber of the parthenocarpic type of foreign breeding were selected based on the sum of economically useful traits.These hybrids were distinguished by a high degree of parthenocarpy. With their participation, as a result of multiple selections and self-pollination, more than 50 breeding lines were created. Analysis of the obtained material showed that the degree of manifestation of parthenocarpy on the plant (the arithmetic mean between the indicators of parthenocarpy on the main and lateral shoots) in the best half of the samples in 2021 was in the range of 30-50%, whereas in 2022 it already reached 50-70%. The parthenocarpy severity coefficient above 70% was noted only in 2022 in 4% of samples. About half of the samples showed a fairly low parthenocarpy: in 2021 no more than 30%, and in 2022 no more than 50%. Most of them were rejected. The parthenocarpy of the best breeding samples in 2022, compared with 2021, increased by an average of 17.7%. Breeding lines obtained even from the same collection sample often differed greatly, sometimes by 4 times, in the degree of parthenocarpy. The families of the most stable parthenocarpy samples had differences on this basis in 2021 only 3-6%, and in 2022 - 10-11%. Families with the greatest severity of this trait were selected annually. It can be concluded that the degree of parthenocarpy in cucumber strongly depends on both the genotype of the sample and the growing conditions. 3 breeding lines were selected, characterized by high indicators of the degree of manifestation of parthenocarpy in 2021 (61.5-70.5%) and the stability of the manifestation of this trait by families and years.