Haploid Culture and UV Mutagenesis in Rapid-cycling Brassica napus for the Generation of Resistance to Chlorsulfuron and Alternaria brassicicola

Abstract

The effect of ultra violet (UV) irradiation on cultured isolated microspores of rapid cycling Brassica napus was investigated. The microscpores were highly sensitive to UV, with the calculated LD50 being an exposure of 20 s. Viability tests suggested that death of the microspores was not immediate, but occurred during subsequent incubation (7 d). None of the embryos produced following UV-irradiation of microscpores showed gross morphological variation. A large number of regenerants was established from embryoids and grown to flowering. These plants set fertile seed after selfing. The progenies were assessed for resistance to Alternaria brassicicola and a small number showed increased resistance to the pathogen, suggesting the generation of novel heritable resistance to this pathogen. In vitro selection revealed heritable resistance to the herbicide ‘Glean’ (active ingredient chlorsulfuron).