Potato cultivars vary in susceptibility to blackleg (<i>Erwinia carotovora</i> subsp <i>atroseptica</i>)

Abstract

Ten potato cultivars were tested for susceptibility to infection by Erwinia carotovora subsp atroseptica (Eca) the causal agent of blackleg over two maincrop seasons in 200506 and 200607 The pathogen was inoculated into seed tubers using toothpicks charged with undiluted bacterial growth Blackleg incidence was assessed 56 weeks after planting The field experiments clearly confirmed that potato cultivars vary significantly in susceptibility to blackleg Some New Zealand cultivars had a lower susceptibility to blackleg than current commercial cultivars The new Plant Food Research release Summer Delight in particular had an exceptional level of resistance and will be used as a parent in efforts to develop potato cultivars with lower blackleg susceptibility than current local commercial cultivars Routine screening of Plant Food Research breeding lines and cultivars will continue to be carried out over several seasons to confirm results presented here and to determine further blacklegresistant germplasm