Stem respiration in leafy cuttings of Prosopis juliflora during the rooting process

Abstract

An oxygen electrode was used to estimate the respiration rate of basal 1 cm sections of Prosopis juliflora cuttings. The respiration rate per unit dry mass decreased linearly with increasing diameter at a rate of 0.42 nmol0₂g⁻¹s⁻¹mm⁻¹ between the range of 1–3 mm diameter. However, as a result of increased mass, total respiration for the whole 1 cm section of tissue increased linearly with increasing diameter. The average respiration rate of the basal 1 cm of stem tissue, measured 14 days after insertion in the propagator, was almost double that of the 1 cm section of tissue above it (1.01 nmol0₂g⁻¹s⁻¹ compared to 0.57 nmol0₂g⁻¹s⁻¹). The value of this technique as an aid to our understanding of the development of adventitious roots is discussed.