In vitro propagation of Lens species and their F-1 interspecific hybrids

As an initial step in establishing interspecific hybridization to broaden the genetic basis of lentils [Lens culinaris ssp. culinaris (Medikus) Williams], a set of experiments was carried out to produce an efficient in vitro protocol for propagation of lentil and two of its wild relatives (Lens ervoides and Lens culinaris ssp. orientalis). The objective of the experiments was to optimize the media (Murashige and Skoog) to regenerate shoots in vitro from nodal segments without a callogenic phase. The number of shoots per explant, the number of nodes per shoot and shoot length showed that species differences, gibberellic acid and benzyladenine levels had the largest effects, with only minor interaction effects. The experiments therefore identified a standard protocol which gave the optimum levels of growth regulators, Murashige and Skoog (MS) salts and sucrose concentrations for maximum plant regeneration from the nodal segment of these species. The medium recommended for optimal shoot regeneration without a callogenic stage contained 2.89 mu M GA(3) in combination with 1.11 mu M BA in MS medium lacking sucrose. The optimal medium for root induction on these shoots had the MS medium supplemented with 5.37 mu M NAA. Final successful establishment of regenerated plants was completed by the transfer to a third medium containing half-strength MS salts.