Rapid Screening of Potato Cultivars Tolerant to Nitrogen Deficiency Using a Hydroponic System

Potato productivity is heavily dependent on the application of nitrogen fertilizers, but the degree of dependence on nitrogen supply varies among cultivars. Increased cultivar tolerance to nitrogen deficiency may increase productivity and reduce environmental impact of potato crops. In this study we screened 20 cultivars for the tolerance to nitrogen-deficient (0.05 mM nitrate) in comparison with nitrogen-abundant (7.5 mM nitrate) nitrate supply using plantlets grown for 15 days in a recirculating hydroponic system. Nitrogen deficiency increased the root-to-shoot ratio in 18 cultivars. Plant total dry weight was reduced by an average of 61% under nitrogen-deficient nitrate supply. Tolerance to nitrogen deficiency was assessed as the total dry weight ratio, calculated as the ratio of total dry weight under nitrogen-deficient to nitrogen-abundant nitrate supply. The cultivars Norland, Raritan, Nipigon and Langlade were significantly more tolerant to nitrogen deficiency than Eramosa, Carleton, and Epicure. The results indicate that the hydroponic system has capacity to rapidly screen a large number of cultivars for tolerance to nitrogen deficiency.