ASSEMENT AND SELECTION OF CUCUMBER VARIETY TYPE WITH FEMALE TYPE OF FLOWERING

Wide use of cucumber hybrids F1 into industry is only possible at the use of lines with female type of flowering as maternal forms. There are difficulties to select such sort of lines and moreover these lines phenotypically may look entirely like female ones often showing the population nature that may be revealed by treatments with growth  substances. Many researchers came to conclusion that gender variationexpressed much in plant ontogenesis and depended on growing conditions. Consequently, to speed up development of female forms, the different growing conditions may be used as provocative background condition. At VNIISSOK in 2013-2015, some self-pollinated female lines with complex of economically valuable traits including resistance to diseases were selected. All these lines under spring greenhouse condition were shown to be entirely female type, belonging to gynoeciumgender type which is characterized by presence only female flowers on the plant. At the same time gender type of the best maternal lines was assessed for economically valuable traits in open field condition. As a result, it was shown that not all female lines, which were entirely female ones in greenhouse condition, also had not male flowers in open field condition. It may be supposed that increase of volume of breeding material being studied and plant growing under harder condition of open field - day and night temperatures variation, lack or abundance of humidity and others - enable to carry out more precise assessment of gender type of maternal forms. According to results of analysis, the open field condition served as provocative background to reveal cucumber lines with strong expression of female flowering. It enabled to have selected eight most promising accessions, which were taken into crossing to test their combining ability.