Multiple shoot regeneration from cotyledonary node explants in chickpea (Cicer arietinum) through direct organogenesis

Abstract

India is the largest chickpea producing country. Several biotic and abiotic constraints limit its productivity. Production of resistant/tolerant chickpea varieties through conventional breeding is limited due to unavailability of sufficient level of resistance in the gene pool. The success of gene transfer technologies largely depends on availability of a rapid, efficient and reliable in vitro plant regeneration protocol. In the present study, an efficient, short and reproducible regeneration protocol has been standardized for chickpea. For preparation of the ex-plants, de-coated mature seeds of chickpea were germinated on a medium fortified with TDZ for seven days. The explants were then cultured on MS medium supplemented with different combinations of benzylaminopurine (BAP), thidiazuron (TDZ) and indole butyric acid (IBA) for multiple shoot regeneration. Pre-culture of seeds with TDZ significantly enhanced the frequency of multiple shoot regeneration from the explants. Ontogeny of the shoots clearly indicated the organogenetic pathway of shoot regeneration and no callus induction. Multiple shoots were elongated on a medium fortified with BAP and gibberellic acid (GA3) and grafted on root stocks prepared from the same cultivar of chickpea.