In vitro propagation of short day onion

Abstract

Onion (Allium cepa L.) is multiplied through seed and sets or vegetatively. The multiplication by seed and sets requires two-year cycle under north Indian conditions. Completing one seed cycle, bulbs are produced through seedlings from November to May, stored for five months and replanted in November to harvest the seed in next May. Handling of bulk quantity bulbs (>25 q ha-1) for 5 months, storage losses (15-40%), higher market prices of bulbs at the time of replanting (> Rs. 1,500 q-1) and risk of diseases particularly purple blotch, downy mildew and stempyllium blight to seed crop are the major limiting factors in onion (Anjaneyulu et al., 1). Genetic contamination by out crossing, inbreeding depression and poor longevity of seed are the other problems with seed multiplication.