https://cucurbitbreeding.wordpress.ncsu.edu/cucumber-breeding/cultivar-types

  • Glasshouse cucumber cultivation is important in northern Europe, Asia, the Middle East and other areas. Glasshouse production of cucumber in the USA has declined in recent years, due to competition in winter from plants grown outdoors in Florida, Mexico and other warm regions. Slicing type cucumber cultivars are most commonly grown in glasshouses. Pickling cultivars have been grown in glasshouses in The Netherlands, but this practice is declining.
  • Glasshouse cucumbers have become popular in markets, commanding a premium price because of their excellent quality. They can often be identified by their very long, slender fruit, with constricted neck, thin skin, indistinct warts and spines, and crisp texture. Their crispness, tender skin and other quality attributes are primarily due to the cultivar, rather than to being grown in a glasshouse. Glasshouse cultivars include the original European gynoecious cultivar ‘Telegraph’ and the related, improved selections ‘Petita F1’ and ‘Superator’. The small-fruited versions such as ‘Hayat’ have resulted in a new type for the Middle East, the greenhouse Beit Alpha.
  • Some of today’s cultivars are known to be centuries old, having originally been developed in Europe or Asia. An example is ‘Early Russian’, which was described by Naudin in France in 1859. Many field-grown cultivars in Europe and the Middle East differ from American cultivars by having numerous fine spines and indistinct warts.
  • Cultivar selection in the USA began in the late 1880s, with emphasis placed on fruit shape and color as well as adaptation to local growing conditions. Many cultivars introduced before 1900 were developed simply by selecting superior plants from the heterogeneous cultivars grown at that time. American and English cultivars were crossed to develop ‘Tailbys Hybrid’, introduced in 1872, and controlled hybridization has subsequently become important in cucumber improvement. Some of the old cultivars that are still available today include ‘Early Cluster’ (1778), ‘Early Russian’ (1854), ‘Chicago Pickling’ (1897), ‘Snows Pickling’ (1905), ‘National Pickling’ (1924), ‘Double Yield’ (1924), ‘Producer’ (1945), and ‘Model’ (1946).
  • Older American cultivars of slicing cucumbers develop stippling at high temperature, i.e. the fruit develops light green spots at the location of the lenticels. Cultivars from Asia and most European glasshouse cucumbers have an allele for uniform green fruit colour (u), and Munger backcrossed this allele into ‘Marketmore 70’ and other breeding lines to produce cucumbers that retain their uniform, dark green fruit colour even at high temperatures. Most slicing cultivars marketed in the USA today have that trait.
  • ‘Maine No. 2’ (released 1939) was the first cucumber cultivar resistant to the scab disease. Its resistance is due to a single dominant allele. Scab is no longer an important disease in most cucumber crops because most current cultivars have that allele, which is linked to resistance to Fusarium wilt resistance, another important disease. Barnes developed ‘Pixie’ (released 1963) with resistance to diseases in the southern USA production areas: downy mildew, powdery mildew, and anthracnose. Resistance permitted a fall crop to be grown, expanding the useful production season. Later, ‘Sumter’ (1973) was released with additional disease resistances to angular leafspot, scab and cucumber mosaic virus.
  • Cultivars resistant to CMV have been available for more than 50 years. Walker combined scab and CMV resistance in ‘Wisconsin SMR 18’ (released 1958) pickling cucumber. A higher level of resistance to CMV, combined with good horticultural type, was achieved in the ‘Marketmore’ series of slicing cultivars bred by Munger. He incorporated resistance to scab and additional diseases into this cultivar by backcrossing. Cucumber breeders continue to combine genes for resistance to different diseases. Peterson developed a breeding line, WI 2757 (released 1982), with resistance to 9 diseases.
  • ‘Burpee Hybrid’, the first F1 monoecious hybrid cucumber cultivar (released 1945), was bred by Shifriss at the Burpee Seed Company. The development of hybrid cultivars became important after gynoecious sex expression was obtained from a Korean cultivar. The genes for gynoecious expression (F F M M genotype) are dominant, and gynoecious hybrid cultivars have a high proportion of female flowers, resulting in early maturity and good yield. Gynoecious hybrids have early and concentrated fruit set, and are suited to mechanical harvest. ‘Spartan Dawn’, introduced in 1962, was the first gynoecious hybrid cultivar. Peterson developed the maternal parent of this hybrid by backcrossing the gynoecious trait (F F M M genotype) into ‘Wisconsin SMR 18 (f f M M genotype)’. The most popular pickling cultivars today are gynoecious hybrids.
  • ‘Lemon’ is a unique cultivar. It has andromonoecious sex expression, whereas other cucumber cultivars are monoecious or gynoecious. The small, round, yellow fruit, which have five placentae instead of the customary three, faintly resembles a lemon fruit, hence its name. Other improvements made by plant breeding include high yield, fruit with high vitamin A, fruit with small seedcell, fruit resistant to damage while in brine tanks (bloater resistance), concentrated fruit set for machine harvest (using gynoecious and multiple branching types), fruit with long length : diameter ratio for stressful environments, and parthenocarpic, seedless cultivars (usually made as hybrids from two parthenocarpic and gynoecious inbred lines) for open field production, thus eliminating the need for pollenizer plants or pollinating insects such as bees.
  • Cucumber breeders in China have developed improved inbred and F1 hybrid cultivars (e.g. ‘Ningqin’, ‘JingYan No. 2’) of the oriental trellis type for production in open field as well as greenhouse. New traits include gynoecy, earliness and multiple disease resistance. Breeders are also trying to improve various traits for autumn crop production. Parthenocarpy has been incorporated to reduce the need for pollination in the greenhouse. For oriental trellis cucumbers, the preferred type is long fruit with dark green skin and thick, prominent spines or ridges.
  • Breeders worldwide continue to select for a wide range of desirable characteristics, in addition to disease and pest resistance. Cultivars have been bred for tolerance to cold, heat, drought, herbicides, sulphur dioxide and soil salinity. Pickling cucumbers have been bred to withstand carpel separation in order to prevent bloating during the brining process. Cucumber cultivars differ in the time required for their fruit to develop from the optimal size for market to oversized fruit of little value, and ‘Marketer’ has become important because it produces a large proportion of fruit of marketable stage.
  • The littleleaf mutant (ll ll genotype) was discovered by Bowers and Goode. Its multiple branching and multiple fruit setting traits were desirable for once-over harvesting systems, but there were problems with slow fruit development (common to mutants having multiple fruit set) that led to fruit having tough skin, large seeds, and a watery (mature) seedcell. Currently, parthenocarpic (seedless fruit development without pollination) cultivars that promise high yield are being evaluated for machine-harvest systems of pickling cucumbers in the USA and Europe. Problems that need to be solved are unreliable fruit set, and tough skin in the larger fruit sizes.
  • Littleleaf (front) vs. normal leaf (rear) JPEG image.