Genotypic Variation in Ethylene Production by Maize Grown under Nutrient Deficiency

Abstract

Summary Ethylene production by drought-resistant and drought-sensitive genotypes of maize ( Zea mays L.), grown in full strength Hoagland's solution or in solutions lacking nitrogen, phosphorus, or potassium, was measured to determine genotypic variation of ethylene evolution under nutrient deficiency. Shoot height, root length, total fresh weight, and total dry weight of the plants were also determined. When the plants were grown without N, P, or K, the drought-resistant genotype grew an average of 4.4 cm taller, but had an average root length that was 5.5 cm shorter, than the drought-sensitive genotype. The total fresh and dry weights of the drought-resistant genotype also were greater than those of the drought-sensitive genotype. At the end of the 26-day experiment, total fresh weight and total dry weight of the drought-resistant genotype averaged 0.21 and 0.03 g per plant more, respectively, than those of the drought-sensitive genotype. Ethylene released by the drought-resistant genotype was not affected by nutritional status. However, the drought-sensitive genotype evolved 1.4 times more ethylene under nutrient deficit (-N, -P, -K) than it did when grown with all nutrients. These results showed that genotypes of maize vary in the amount of ethylene evolved under nutrient starvation.