Genetic Control of Blossom-end Rot Disease in Tomatoes through Calcium Metabolism1

Genetic resistance to blossom-end rot (BER) disease of tomatoes, based on Ca metabolism, was revealed in several Auburn University (AU) tomato breeding lines when grown in a Ca-deficient, 1:1 peat:sand medium and watered with nutrient solutions at 4 Ca levels. Three genotypes, represented by 3 AU lines, 2 BER-resistant and 1 susceptible, appear to have 3 distinct mechanisms of Ca utilization, inferred from their fruit Ca levels and their corresponding percentages of BER fruits. The highly BER-resistant line AU-1 appears to be a more efficient absorber and accumulator of Ca, whereas the moderately resistant line AU-3 appears to have a lower Ca requirement for producing non-BER fruits. The highly susceptible line AU-2, on the other hand, has a high Ca requirement but is inefficient at absorbing and translocating Ca. Tomato varieties having either the AU-1 type or the AU-3 type of BER resistance would effectively supplement Ca nutrition as a control measure for this disease. The genetic evidence thus independently confirms the nutritional evidence that Ca is the key element in the control of the BER disease of tomatoes.