Morphology and Taxonomy of Onion
M A Baset Mia
Common name: Onion
Scientific name: Allium cepa L.
Local/Bangla name: ‘Piaj’
Taxonomic Position According to Cronquist (1988)
Kingdom: : Plantae
Division: : Magnoliophyta
Class: : Liliopsida
Subclass: : Liliidae
Order: : Amaryllidales
Family: : Liliaceae
Genus: : Allium
Species: : A. cepa
Botanical Description of Onion:
Habit: Annual herb.
Root: Fibrous root system.
Leaf: Radical concentrically arranged, exstipulate, sessile, cylindrical, fistular, leaf bases fleshy, parallel venation. Leaves are arranged on the disc-like stem in concentric circles.
Inflorescence: Terminal raceme umbel.
Flower: Pedicellate, complete, bisexual. Perianth 6, stamens 6, inserted at the base of the perianth lobes, filaments free, somewhat dilated below, anthers oblong, stigma one.
Fruit: Fruit a membranous capsule.
Seed: Seeds compressed, black.
blade partly decurrent upon it in the upper portion. The lamina is lanceolate or narrowly elliptical or obovate, the apex is shortly or broadly bluntly acuminate and the base is cuneate.
Flower: The inflorescence is a terminal, corymbose, trichotomous panicle, shortly pedunculate and branched from the base. The flower is hermaphrodite with a fleshy hypanthium which is surmounted by the sepals. The four calyx lobes are fleshy, triangular, slightly incurved. The four petals are imbricate, tinged red, rounded. The stamens are very numerous, appearing grouped in four masses. The anthers are pale-yellow, ovate, opening longitudinally wit small pale brown in colour, The style is very stout, swollen at the base, pale green and gland-dotted.
Fruits: The fruits called mother of cloves are oblong, fleshy, drupes, usually shortly tapering at each end reddish purple in color. They are surmounted by the four enlarged fleshy calyx lobes. There is a thin fleshy pericarp about 2-3 mm thick.
- Used as spices
- Used as vegetable
- Has medicinal virtue
Table 1. Onion variety developed by Spices Research Center (SRC), BARI, Joydebpur and Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh, Bangladesh
|Sl. No.||Name of Variety||Developed by||Year of Release||Growing Season||Yield||View|
|1||BARI Piaz-1||HRC||1996||Rabi||12-16t/ha, seed yield 600-650kg||View|
|2||BARI Piaz-2||SRC||1999||Kharif||18-22t/ha (bulb); 350-400kg/ha (seed)||View|
|3||BARI Piaz-3||SRC||2000||Kharif||14-16 t/ha (bulb); 259-300 kg/ha (seed)||View|
|4||BARI Piaz-4||SRC||2008||Rabi||18-20 t/ha||View|
|5||BARI Piaz-5||SRC||2008||Kharif||17-22 t/ha||View|
|6||BARI Bunching Onion-1||SRC||2014||Throughout the year||10-13 t/ha||View|