J. Phys. IV France 125 (2005) 865-867
DOI: 10.1051/jp4:2005125200

Photoacoustic technique applied to ethylene emission in passion fruit seedlings: An experimental approach

T. Pereira¹, M. Baptista-Filho¹, S.F. Corrêa¹, J.G. de Oliveira², M.G. da Silva¹ and H. Vargas<sup>1

1</sup>  Laboratório de Ciências Físicas/CCT/UENF, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Centro de Ciência e Tecnologia, Av. Alberto Lamego 2000, Pq. Califórnia, CEP 28015-620, Campos dos Goytacazes, RJ, Brazil
²  Laboratório de Melhoramento Genético Vegetal/CCTA/UENF, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Centro de Ciência e Tecnologia, Av. Alberto Lamego 2000, Pq. Califórnia, CEP 28015-620, Campos dos Goytacazes, RJ, Brazil

Abstract
It is well known that plants respond to mechanical perturbation, such as swaying in the wind, touching or brushing, by a reduction in stem length and an increase in stem diameter. Brushing provides a tactile or thigmic stimulation of the plant growing points and undergo physiological and developmental changes that increase stress tolerance. One of the main hormones released by brushing plants is thought to be ethylene, a plant hormone difficult to trace and monitor because it is a gas. The emission rate of ethylene was monitored using a photoacoustic spectrometer based on the infrared absorption of the line 10P12 and 10P14 of CO₂ LASER. In response to the brushing treatment, seedlings of passion fruit (Passiflora edulis L.) showed a increase in the ethylene emission. The aim of this work was to investigate the effect of brushing on the ethylene emission rate of passion fruit seedlings.

© EDP Sciences 2005