Investigation on the resistance of doubled haploid sunflower lines to some biotic factors

M. Drumeva, P. Yankov, N. Nenova, P. Shindrova
Abstract. The investigation was carried out at the Laboratory facilities of Dobrudzha Agricultural Institute (DAI), General Toshevo, Bulgaria during 2010 – 2012, and involved 15 doubled haploid fertility restorer sunflower lines (R-lines). The lines were obtained by the gamma-induced parthenogenesis method under greenhouse conditions in 2007 from three hybrid combinations developed at DAI. The resistance of the plants to downy mildew – one of the main pathogens on sunflower, and to the parasite broomrape was followed. The breeding materials were infected with downy mildew (Plasmopara halstedii), race 731, and broomrape (Orobanche cumana Wallr.) under greenhouse conditions. The evaluation for resistance was done according to a scale from 0 % (susceptible genotype) to 100 % (resistant genotype). To determine the resistance to downy mildew, standard methodology was applied, adapted for work under the specific conditions of DAI; the methodology of Panchenko (1975) was used to determine the resistance to broomrape. Four lines demonstrated complex resistance to downy mildew and broomrape. Among the other eleven lines, three lines showed 100 % resistance to downy mildew race 731, and five lines were resistant to Orobanche (races A-F).