Study of Potential of Callus Induction and In vitro Regeneration in Red Azarshahr and Qoolquesseh Zanjan Onion Varieties

Onion is one of the main vegetables in Iran and there are no report on in vitro regeneration of commercially important onion varieties grown in Iran. Therefore, this study was carried out in order to evaluate the effect of culture medium and genotype on callus induction and regeneration of two onion varieties using root tip culture with factorial arrangement in CRD with three replications. Root tip explants of two- day- old sterilized seedlings which were 3 mm long, were cultured in medium N6 plus two concentrations of 2, 4-D (0.5-1mg L-1) and with or without Kinetin (0.5-1mg L-1). Analysis of variance showed significant differences between varieties and culture media for all traits. However, there was no significant variety × culture media interaction. Results showed that callus induction (%) per explant, embryogenic callus (%), number of embryo per callus, plant regeneration (%) per callus and the number of plants produced per explant in Red Azarshahr were more than Qooloquesseh Zanjan. The N6 medium supplemented with 2, 4-D 0.5 mg L-1 can be used for callus induction and regeneration in onion.