Effect of Alternaria helianthi culture filtrate on callus and regeneration of plantlets from tolerant callus in sunflower (Helianthus annuus L.)

Abstract

A protocol for selecting callus line tolerant to culture filtrate of Alternaria helianthi (ACF), which causes severe blight disease, was developed in sunflower using 40% ACF as selection pressure. In vitro plantlets were obtained from the selected callus on Murashige and Skoog's (MS) medium fortified with 2.0 mg/L N-6-Benzyl amino purine (BAP) and 0.5 mg/L ?-Naphthalene acetic acid (NAA). The plantlets obtained were rooted on MS medium fortified with 1.0 mg/L NAA or IBA. NAA proved better for rooting than IBA. In the preliminary experiments, in vitro developed plants from selected callus showed fewer symptoms of disease when spore suspensions of A. helianthi, was sprayed on the leaves.