Studying allozyme variation in sexual and apomictic Taraxacum and Pilosella (Asteraceae) populations

Allozyme spectra of peroxidase, esterase, superoxid dismutase, tyrosinase, alcohol dehydrogenase, lactate dehydrogenase, and acid phosphatase were examined in populations of sexual (Taraxacum serotinum and Pilosella echioides) and apomictic (T. officinale and P. officinarum) plant species. The heterozygosity in these populations (0.455-0.620) proved to be considerably higher than the average level characteristic of plant populations (0.058-0.185). The populations examined did not differ in the mean phenotype number mu , i.e., they exhibited the same diversity (3.188-3.380). The proportion of rare phenotypes h also did not differ between the sexual and apomictic species of the same genus, whereas this parameter in the Pilosella populations (0.150-0.174) was significantly higher than in the Taraxacum ones (0.093-0.114). The populations were characterized by numerous isozyme spectra (more than 11 per populations) and displayed multiple allelism (the mean allele frequency was 3.63-4.38 per locus). They exhibited a high percentage of rare (occurring at a frequency lower than 5%) spectra (35-80%). This indicates that agamic complexes, to which these populations belong, may have a more complicated genetic structure of both apomictic and sexual populations than the species that do not belong to agamic complexes.