Taxonomy

  • Cucumis sativus var. hardwickii (wild cucumber)
    • Cucumber has been improved by using accessions of the wild var. hardwickii. Traits such as resistance to nematode (Meloidogyne arenaria and M. javanica) have been transferred from LJ 90430, resulting in the cultivars Lucia, Manteo and Shelby.
    • Some traits of hardwickii, including littleleaf (ll-2), black spine (B-3, B-4) and multiple-branching are not the same (are non-allelic) compared with cucumber. For example, Arkansas Littleleaf, and black spined (B-1) Wis. SMR 18 have similar traits, but hardwickii has different genes for those traits. Cucumis sativus var. hardwickii (top) compared with Cucumis sativus (bottom) see image (JPEG).
  • Cucumis sativus var. sikkimensis (Sikkim cucumber)
    • Large, oblong fruit are also found among cultivars of Cucumis sativus var. sikkimensis Hook. f. (Sikkim cucumber). It has been reclassified as Cucumis sativus var. sativus. These cultivars are grown primarily in mountainous Nepal and India. The Sikkim cucumber has accessions that represent much variation, including high resistance to downy mildew, and five-carpellate fruit see image (JPEG).
  • Cucumis sativus var. xishuangbannanensis (Xishuangbanna gourd)
    • A distinct group of cultivars, known as Xishuangbanna gourd, is classified as C. sativus var. xishuangbannanensis Qi & Yuan. Grown by the Hani people of southwestern China at elevations of 1000 m or higher, these landraces are largely unknown outside of eastern Asia. The Xishuangbanna gourd has much variation and includes cultivars with five-carpellate fruit. It is more closely related to Cucumis sativus var. sativus than to C. s. var. hardwickii.
    • Vines of this variety are vigorous, reaching up to 7 m in length. The large mature fruit is oblong and weighs about 3 kg. The rind is white, yellow or brownish-orange, sometimes with distinct netting, but otherwise relatively smooth and without prominent warts. Because the yellow to orange flesh color is caused by provitamin A carotenes, researchers have transferred the trait (light orange mesocarp, orange seedcell) controlled by the ore gene from the Xishuangbanna gourd to cucumber cultivars see image (JPEG).
  • Cucumis hystrix
    • Cucumis hystrix is a wild species of Cucumis that can be crossed with C. sativus to produce, after chromosome doubling, an allotetraploid. The new species is C. hytivus, and lines have been developed that have characteristics of processing or fresh market cucumbers, along with other traits not present in cucumber. Introgression lines were produced by Chen and co-workers that have introduced disease resistance to cucumber.
    • Resistances obtained from crosses with C. hystrix include gummy stem blight and downy mildew. C. hystrix offers a way to increase the genetic diversity of cucumber, already known to be rather narrow. No other species has been crossed successfully with cucumber, although the two botanical varieties, C. sativus var. hardwickii (formerly C. hardwickii) and C. sativus var. xishuangbannanensis, will cross readily with cucumber. See hystrix x sativus hybrid (JPEG).
  • Cucumis sativus (Cucumber)
    • Overview
    • Origin and History
      • Cucumber is of Asiatic origin along with the closely related, wild Cucumis sativus var. hardwickii, which was first found in the Himalayan foothills of Nepal. Plants of this botanical variety are highly branched, daylength sensitive and prodigious producers of bitter fruit. The most closely related species to cucumber (2n=2x=14) is Cucumis hystrix (2n=2x=24). Both species are more closely related to the species of Australia and New Guinea, such as C. umbellatus, than to the African species, such as C. hirsutus, C. metuliferus, C. myriocarpus, C. anguria and C. sagittatus. Cucumber diverged from C. hystrix 4.6 million years ago, and the cucumber / melon relative diverged from its African relative 11.9 million years ago. Based on the recent sequencing of the Lagenaria genome, Lagenaria diverged from Citrullus 10.4 to 14.6 million years ago, from Cucumis 17.3 to 24.3 million years ago, and from Momordica 29.2 to 41.0 million years ago.
      • Cucumber remains in eastern Iran have been dated to the third millennium bc. Cucumber cultivation goes back at least 3000 years in India and 2000 years in China. China is considered a secondary centre of genetic diversification. Today, cucumber is one of the most important vegetable crops in that country, second only to Chinese cabbage in area cultivated.
      • Cucumber was probably not known to the ancient Egyptians, Greeks or Romans. The Latin cucumis, Greek sikyos and Hebrew qishu’im refer to the snake melon, Cucumis melo var. flexuosus. In English translations of the Bible, cucumber and melon are referred to in Numbers 11:5, but that probably should have been translated as snake melon and watermelon. Snake melon fruit can be distinguished by small hairs (fuzz) on the surface, whereas cucumber fruit are smooth, with ridges, warts, or spines.
      • Early travellers brought cucumber to Mediterranean countries from India through Iran, Iraq and Turkey in the 6th or 7th centuries. Cucumber probably reached Spain in the 9th century, and Tunisia in the 10th century. In the early 14th century, cucumber plants were cultivated in England. There, the fruit were known as ‘cowcumbers’. Portuguese explorers subsequently carried cucumber to West Africa. Columbus introduced this species to the New World, planting it in Haiti in 1494. Today, cucumber is grown throughout the world in patio containers, small gardens often using trellises, large commercial farms, unheated high tunnels and heated greenhouses.
    • Taxonomy and Wild Relatives