NEW PARTHENOCARPIC CUCUMBER HYBRIDS TOLERANT TO DOWNY MILDEW

Research work was carried out in the State University "Transnistrian Research Institute of agriculture" in film greenhouses (spring-summer and summer turnover) and in the open field on the trellis. The aim of the work is to study the source material and create promising lines of cucumber with high parthenocarpic ability, yield and resistance to downy mildew to obtain on their basis heterosis hybrids of cucumber of universal type for various crop rotations. To achieve this goal in 2013-2017 the following tasks were identified: to study the collection samples and to identify the most resistant to downy mildew; to evaluate the source material and select the stable forms; to study the combinational ability of the main features and properties of the parent forms of cucumber hybrids (parthenocarpy, yield, disease resistance); to study the variability and inheritance of the main useful features and properties; to test promising cucumber hybrids for economically valuable traits and properties. The standards were hybrids Enthusiasm (selection RF) and Claudia (Dutch selection). In order to create a source material of parthenocarpic hybrids of cucumber resistant to peronosporosis, 20 samples of breeding material from different countries of origin were studied in the closed and open ground. Four maternal and six paternal forms, as well as eighteen large-humped hybrid combinations were evaluated by the topcross method according to the complex of economically valuable traits and properties. And full diallele the scheme of the seven lines and forty-two tuberculate hybrid combinations. The regularities of variability and signs manifestation in the first generation of hybrids are studied. Given information about the inheritance of the trait of resistance to downy mildew is a promising parthenocarpic hybrid combinations of cucumber created in the Transnistrian agricultural research Institute. Highlighted is sixty-six hybrid combinations of cucumber. Three samples that showed high resistance to downy mildew, was submitted to the State varietal Inspectorate of the Republic of Moldova and Transnistria under the name Condor, Orlan and Shegol.