VITALITY OF PINE POLLEN (PINUS-SYLVESTRIS L AND PINUS-NIGRA ARNOLD) ON SITES WITH DIFFERENT ECOLOGICAL CONDITIONS

Fertilizing ability of pine pollen (Pinus sylvestris L., Pinus nigra Arnold) has been assessed according to pollen vitality tested in vitro (germination percentage and the length of the pollen tubes). Differences in pollen vitality between various sites have been found. Average pollen germination fluctuated among site in Pinus sylvestris L. from 13% to 74% and in Pinus nigra Arnold from 30% to 76%. The lowest pollen vitality was recorded in trees grown at extremely polluted sites (close to main town road). Analysis of variance has proved that pollen vitality was significantly influenced by sites and years, namely by specific external conditions on given site in given year. Total pollen sterility was not found what indicates certain tolerance of male reproductive organs to unfavourable environmental conditions.