The investigation of relationship between reducing sugar (RS) content in tubers andtheir resistance to soft rot (Erwinia carotovora pv.carotovora) was carried out in severalaspects.In all tests,RS content in periderm tissues was not found to be associated withtheir resistance to lenticel infection.The relation between RS content in medullar tissuesand resistance to infection by pepitte injection was various based on test conditions.Ascompared with the relations between varieties,there was no relation betwee...