Genetic variation in sexual and apomictic Taraxacum officinale and growth in heterogeneous environments

Producing genetically variable offspring could be advantageous in a heterogeneous environment, given a number of assumptions are met about the nature of this environmental heterogeneity, the mode of selection, and the way in which different genotypes differ from each other. In this study, I grew sexual and apomictic Taraxacum under four different conditions to test whether these assumptions are likely to be met. In the first experiment, pots containing 12 seeds from a sexual mother or 12 seeds from an apomictic mother were grown under four light-moisture conditions. In the second experiment, mixtures as well as pure cultures of apomictic genotypes were grown under the same set of four conditions. Sexual as well as apomictic Taraxacum were genetically variable. Different genotypes responded in different ways to the treatments. Asexual families reacted in the same way to treatments as mixtures of genotypes. Selection seemed a mixture of soft and hard selection. The consequences of these results for theories about the consequences of sexual reproduction are discussed.