GENOTYPIC DIFFERENCES IN DARK RESPIRATION OF MATURE LEAVES IN WINTER WHEAT (Triticum aestivum L.)

Abstract

Oxygen uptake of mature leaves was measured on a range of winter wheat (Triticum aestivum L.) genotypes both indoors (four genotypes) and in the field (six genotypes). The relationship among mature leaf respiration, leaf size, specific leaf weight and leaf nutrient status was investigated. Correlations between leaf respiration and total plant dry weight as well as tiller number were calculated in the indoor study. Significant differences of 6–25% in mature leaf respiration rates were evident among winter wheat genotypes in the indoor as well as in the field study. Leaf position as well as environment had a marked influence on the order and magnitude of genotype effects on mature leaf respiration rates. Leaf respiration was not related to specific leaf weight, leaf nitrogen, or phosphorus content, but was negatively related to leaf size. Leaf respiration was not related to total dry weight and tiller number of single plants grown indoors.Key words: Respiration, genotypic differences, wheat (winter), Triticum aestivum L.