Cucumber: Cucumis sativus L.

TLDR: The use of this vegetable is highlighted and its cytology, genetics, germplasm resources, and reproductive biology are reviewed and techniques applicable to the improvement of cucumber are described.

Abstract: Publisher Summary Cucumber, Cucumis sativus L., is a member of the Cucurbitaceae, which comprises 90 genera and 750 species. It is one of the oldest cultivated vegetable crops and is cultivated in nearly all countries of temperature zones. It is a thermophilic and frost-susceptible plant species, growing best at temperatures above 20 °C. This chapter highlights the use of this vegetable and reviews its cytology, genetics, germplasm resources, and reproductive biology. The taste and demands of the consumer varies according to country. Special varieties must be bred that set fruit under suboptimal temperature conditions. The demands of the processing industry concerning outer appearance—fruit shape, size, and color—also varies depending on the preservation process and the corresponding country. Therefore, cucumber breeders must consider several different breeding aims. General breeding objectives in cucumber are resistance to diseases and animal pests, maintenance of resistance in existing varieties, fruit quality, and fruit yield. Additionally, breeding aims such as parthenocarpy, constancy of femaleness, germination, and fruit set at suboptimum temperatures may be of importance in special breeding programs. Unlike many other plant species, there are different sex types in cucumber, which are of different value in breeding and concerning yield potential. By using sex inheritance and influencing sex expression, the breeding methods of self-pollinated and open-pollinated plants can be applied to cucumber. Thus, the cucumber breeder needs complete knowledge of sex inheritance and of potential ways of influencing sex expression. The chapter provides an overview of the selection of cucumber breeding methods and these methods. There have been several reports on the possibility of applying in vitro techniques in plant breeding of cucumber. The chapter describes techniques that are applicable to the improvement of cucumber.