An Inborn Error of Potassium Metabolism in the Tomato, Lycopersicon esculentum

A mutant of the tomato (Lycopersicon esculentum Mill.) was obtained through treatment of the seed with ethyl methane sulfonate. Its chief distinguishing characteristic is the requirement for an extraordinarily high K concentration in the medium (20 mm) if it is to develop without pronounced K deficiency symptoms, while the wild type grows without any such symptoms at 0.1 to 0.2 mm K. The lesion of the K-inefficient mutant does not lie in its inability to absorb and translocate K.