ZINC TOLERANCE IN POPULATIONS OF DESCHAMPSIA-CESPITOSA (GRAMINEAE) BENEATH ELECTRICITY PYLONS

Patterns of zinc tolerance were examined in eight Deschampsia cespitos a (L.) BEAUV. populations from normal and zinc-contaminated soils. usi ng solution culture methods. Zinc-tolerant populations have evolved be neath pylons, and their tolerance patterns (degree, variance, heritabi lity) vary. Tolerance is genetically based in all of them. In contrast to the cases of other species previously reported, some within-popula tion differences are considerable, and may be due to both heterogeneit y of the soils zinc contents, various gene combinations and gene recom binations between genotypes. One control population contains many tole rant plants, an original result which is discussed.