Fasciation in cucurbits

The article presents a literature review on fasciation in pumpkin crops. In almost all pumpkin crops, you can find such a phenomenon as fasciation. However, it is more common in cucumbers and pumpkins than in melons and watermelons. Fasciation (or crystallization) is a change that can occur in the morphology of plant organs and usually includes expansion of the apical meristem of the shoot, flattening of the stem and changes in the arrangement of leaves. In pumpkin crops, the fasciated organs are often whips, flowers and fruits. A number of authors divide fasciations into inherited and non-inherited. The first are caused by internal reasons. The second is the effect of external factors, such as insect damage, injury, weather conditions. According to literature data, fasciation is caused by 1-2 recessive genes with incomplete manifestation and variable expression, which depends on a number of factors, including environmental conditions. The opp gene may have a pleiotropic effect on fasciation and leaf arrangement. In Federal Scientific Vegetable Center in spring film greenhouses, among the selection and collection samples of cucumber, fasciated plants ranged from 0 to 1.9%, depending on the genotype of the studied samples and the year of research (growing conditions). According to literature data, fasciation is more often observed in short-fruited, but it can also be detected in long-fruited forms of cucumber. Fused fruits are more likely to appear on cucumber hybrids with a large number of ovaries in the node. It should be noted, that highly fasciated plants are usually less productive, and most fasciated fruits are often classified as non-standard and rejected. Regular culling by breeders of fasciated samples and plants, within individual samples, will allow to create varieties less prone to fasciation. And compliance with the recommended varietal agrotechnics, improvement of the ecological situation will help to significantly reduce the number of fasciated plants and fruits and improve the marketability of products.