In Vitro selection of groundnut cell lines fromCercosporidium personatum culture filtrates and regeneration of resistant plants through cell culture

Cell suspensions derived from immature leaves of the groundnut (Arachis hypogaea L.) were cultured in the presence and absence ofCercosporidium personatum pathotoxic culture filtrates. Cell viability and reactions of cell lines were determined after exposure to various concentrations (25–100%, v/v) of the filtrates. Cell lines have been selected for resistance to the toxin(s) produced byC. personatum. Selected cell lines were used for plant regeneration on regeneration media containingC. personatum culture filtrates. Plant regeneration frequency was found to be low in long-term cultures, whereas it was high in short-term cultures. The selfed progeny of the plants regenerated from the resistant cell lines showed resistance to the pathogen in the field. Six out of 82 plants exhibited enhanced resistance in the R2 generation. The culture filtrate stimulated callus proliferation as well as plant regeneration at lower concentrations, a response that could prove to be very useful for obtaining disease resistant plants throughin vitro selection.