Evaluation of potato cultivars and breeding lines for susceptibility to tuber soft rot induced by <i>Erwinia carotovora</i> subsp <i>atroseptica</i>

Abstract

Bacterial soft rot of potato tubers in storage is an economically important postharvest disease worldwide Disease control measures include reduction of tuber damage at harvest provision of suitable storage conditions and breeding of resistant cultivars Tubers of 18 potato cultivars and breeding lines were assessed for susceptibility to infection by Erwinia carotovora subsp atroseptica (Eca) over three maincrop seasons between 2003 and 2007 Susceptibility to Ecainduced soft rot was determined by measuring the weight of rotted tissue in anaerobically incubated whole tubers 7 days after inoculation with Eca Potato lines differed in susceptibility to soft rot by a factor of >37 (weight of rotted tissue) Cultivars Crop 28 Ilam Hardy and 30975 were highly susceptible and 065/27 Crop 15 and Crop 16 were least susceptible to Ecainduced soft rot As a consequence of these trials several of these lines are now being used in Plant Food Researchs potato breeding programme in order to develop cultivars with lower soft rot susceptibility than cultivars currently grown