A spectrum of peroxidase isozymes and allozyme variability at two poly
morphic loci Per-3 and Per-5 were studied in needles of Scotch pine (P
inus sylvestris L.) by means of disc electrophoresis in vertical polya
crylamide gel slabs. Among the sample analyzed (n = 282), levels of ob
served (H-o) and expected (H-e) mean heterozygosities at both loci wer
e 0.120 and 0.152, respectively. A significant deficit of heterozygote
s at the Per-3 locus was observed.