In vitro effect of formaldehyde on Douglas fir pollen

Abstract

Formaldehyde (HCHO) concentrations of up to 479 mmol m-3 have been reported in urban fogwater, yet little is known about the phytotoxicity of HCHO at such concentrations. We report that formaldehyde at target concentrations of 300, 600, 900 and 1200 mmol m-3 reduced germination of Douglas fir [Pseudotsuga menziesii (Mirbel) Franco.] pollen in vitro. Formaldehyde concentrations and pH in media containing pollen decreased over 25 h. These effects were not seen with heat-killed pollen nor with media lacking pollen, which may suggest uptake or detoxification by live pollen. Stress was indicated by ion leakage from pollen, which increased within 20 h in all HCHO treatments. Reduced pollen viability was indicated by TTC staining of pollen, which decreased after HCHO treatment.