Effect of air traffic pollution on seed quality characteristics of Pinus brutia

This study was undertaken to examine to what degree traffic air pollution affect the reproductive material (the seeds) of Pinus brutia. The study focused on the investigation of the seeds morphological characteristics and physiological attitudes as well as heavy metal concentrations of P. brutia trees grown close the ring-road of Thessaloniki (Greece's second biggest city), polluted by heavy traffic conditions, and how these characteristics are changed with the distance from the pollution source. A sampling procedure was established for seed collection from various distances from the pollution source. Seeds were properly prepared, measured for their morphological characteristics and heavy metal concentrations, as well as for their physiological behaviour (germination and viability). Analysis of the results showed that even though there were no significant differences in seed heavy metal concentrations, and only few in seed morphological characteristics, related to the distance from the traffic pollution source, there was a significant alteration of physiological behaviour for the seeds originated closed to the traffic. All the seed collected close to the ring-road (sample distances 0 and 30 m from the road) were unable to germinate, even those subjected to pre-treatments and repeated germination trials over longer duration, while those collected from distances over 100 m from the ring-road showed a common germination behaviour.

► Traffic air pollution affects the quality of Pinus brutia seeds collected near to the traffic road.
► Physiological behaviour of the seeds originated closed to the traffic was greatly affected.
► All the seeds collected close to the ring-road of Thessaloniki were unable to germinate.
► Seeds heavy metal concentrations were not affected by the distance from the pollution source.
► Only few differences in seed morphological characteristics were found.