CHEMICAL VARIATION WITHIN AND BETWEEN INDIVIDUALS OF THE LICHENIZED ASCOMYCETE TEPHROMELA-ATRA

HPLC-analysis was used to determine the concentrations of the lichen c ompounds alectoronic acid (depsidon), alpha-collatolic acid (depsidon) and atranorin (depsid) in the lichenized ascomycete Tephromela atra ( syn. Lecanora atra) (Hudson) Hafellner from limestone walls on the Bal tic island of bland, Sweden. In 24 individuals of T. atra sampled on a stone wall, the pre-reproductive and reproductive tissue did not diff er in the concentrations of alectoronic acid, collatolic acid and atra norin. The concentrations of the three lichen compounds were inter-cor related in the reproductive tissue, but not in the pre-reproductive ti ssue. Single individuals of T. atra ranged in area covered from 10.1 t o 147.4 cm(2) (mean: 38.5 cm(2); N=24); 38.6% of this area was pre-rep roductive tissue. However, the concentrations of the three lichen comp ounds were correlated neither with the total area covered by the liche n nor with the percentage of pre-reproductive tissue. This suggests th at the concentrations of the lichen compounds do not change with incre asing size (age) of the lichen. Analysis of specimens of T. atra from eight localities revealed a significant variation in lichen compounds (range between localities: alectoronic acid 0.60-3.26 mu g/mg lichen d ry weight (DW); collatolic acid 2.14-11.59 mu g/mg lichen DW; atranori n 0.58-4.16 mu g/mg lichen DW). The level of grazing observed in the l ichens differed significantly among localities. However, no correlatio ns between the concentrations of the three lichen compounds and the gr azing damage to the lichens were found. Copyright (C) 1986 Published b y Elsevier Science Ltd