MARKER-ASSISTED SELECTION (MAS) AND GENOTYPING IN THE DEVELOPMENT OF CUCUMBER HYBRIDS FOR GREENHOUSE CULTIVATION

Abstract

Cucumber (Cucumis sativus L.) is one of the principal greenhouse vegetable crops, and modern production relies predominantly on F₁ hybrids. Because pollinating insects are absent under protected cultivation, high and stable yield depends on parthenocarpy (fruit set without fertilization) combined with stable gynoecy (female-only flowering). Resistance to powdery mildew (Podosphaera xanthii) and downy mildew (Pseudoperonospora cubensis), together with non-bitter fruit, are further essential requirements. This paper reviews a marker-assisted selection (MAS) and genotyping strategy for developing greenhouse cucumber hybrids. The key genes and QTL controlling the target traits — parthenocarpy (Parth2.1, Parth6.1), gynoecy (F/CsACS1G), disease resistance (dm1/CsSGR, CsMLO1) and bitterness (Bi, Bt) — and their linked DNA markers were analysed. A marker-assisted backcrossing (MABC) scheme aimed at pyramiding the target traits into elite lines is proposed. Compared with conventional phenotypic selection, MAS increases selection accuracy, reduces the number of generations, and enables early, environment-independent selection.