The influence of ozone on Pinusstrobus L. pollen germination

Abstract

Along the Blue Ridge Parkway in Virginia, branchlets and pollen were collected from native eastern white pine (Pinusstrobus L.) trees that were sensitive, intermediate, and tolerant to oxidant air pollution based on foliar symptom expression. Fumigation of branchlets with 0.10 ppm ozone (O3) for 4 or 8 h/day until anthesis did not affect pollen production or germinability. However, the percent germination was significantly (P ≤ 0.01) reduced in pollen exposed under wet conditions to 0.15 O3 for 4 h. The importance of this finding in the reproduction of pines is discussed.