Origin, distribution, taxonomy, botanical description, cytogenetics, genetic diversity and breeding of Okra (Abelmoschus esculentus (L.) Moench.)

Okra, (Abelmoschus esculentus), herbaceous hairy annual plant of the family Malvaceae. Okra originated somewhere around the Ethiopia, and was cultivated by the ancient Egyptians by the 12th century B.C. Its cultivation spread throughout Middle East and North Africa. There are two hypotheses concerning the geographical origin of A. esculentus. Some authors argue that one putative ancestor (A.tuberculatus) is native to Uttar Pradesh in northern India, suggesting that the species originated from this geographic area. Others, on the basis of ancient cultivation in East Africa and the presence of the other putative ancestor (A. ficulneus), suggest that the area of domestication is north Egypt or Ethiopia, but no definitive proof is available today. Although about 50 species have been described, eight are most widely accepted. Most of cultivated varieties are amphidiploids with 2n=130. A. esculentus is noted for its chromosome polymorphism and 2n ranges from 72 to 144. It tolerates addition or deletion of one or a few chromosomes. Okra or bhendi is a common vegetable in India. The common names are Ladies Finger, Okra, Bhindi (Hindi), Dhenras (bengali), Vendai (Tamil), bhindo (Gujarati), Bendekayi (Kannada), Ventaykka (Malayalam), Asra-pattraka (Sanskrit). Okra has many interesting uses and is known to be an economically important vegetable crop because its fresh leaves, buds, flowers, pods, stems and seeds all have value. It can be used in salads, stews, fresh or dried, and fried or boiled. It is used as a thickening agent in Charleston gumbo. Breaded, deep fried okra is served in the southern United States. The immature pods may also be pickled. The composition of okra pods per 100 g edible portion is water 88.6 g, energy 144.00 kJ (36 kcal), protein 2.10 g, carbohydrate 8.20 g, fat 0.20 g, fibre 1.70 g, Ca 84.00 mg, P 90.00 mg, Fe 1.20 mg, β-carotene 185.00 μg, riboflavin 0.08mg, thiamin 0.04 mg, niacin 0.60 mg, ascorbic acid 47.00 mg. Protein, carbohydrate and vitamin C contains of okra. It’s medicinal value has also been reported in curing ulcers and relief from hemorrhoids. Unspecified parts of the plant were reported in 1898 to possess diuretic properties this is referenced in numerous sources associated with herbal and traditional medicine. Okra has found medical application as a plasma replacement or blood volume expander. It is also good source of iodine which is useful in the treatment of simple goiter and source of other medically useful compound. In okra, we follow the breeding methodologies of autogamous plants. This includes crossing or controlled hybridization of parents selected based on their better-combining abilities. This is followed by the pedigree selection of the segregating population for the traits of interest like biotic and abiotic stress tolerance and yield. The major breeding objectives are nearly the same across all the okra-growing countries: high yield, tolerance to various pests and diseases, better organoleptic qualities, appealing color and size of the harvestable fruits. Bhendi varieties and cultivars differ in growth habit, height of plants, presence of purple pigmentation on plant parts, length, colour and number of ridges of fruit. It is commercially grown in India, Turkey, Iran, West Africa, Yugoslavia, Bangladesh, Afghanistan, Pakistan, West Bengal, Burma, Japan, Malaysia, Brazil, Ghana, Ethiopia, Cyprus, and the southern USA. In this review article origin, distribution, taxonomy, botanical description, cytogenetics, genetic diversity, breeding, uses, nutritional value, and health benefits of okra are discussed.