The genetic structure of the gynodioecious Kallstroemia grandiflora (Zygophyllaceae): the role of male sterility and colonization history.

ABSTRACT

In gynodioecious populations, the frequency of females is expected to have a strong influence on the contemporary genetic structure of populations. Historical patterns of range contraction and expansion are also known to influence the genetic diversity of plant populations. We explore the influence of male sterility and colonization history on the genetic diversity in populations of Kallstroemia grandiflora along the Pacific of México. Both the overall population Fis and Fis values of hermaphrodites showed a negative association with female frequency. Genetic diversity declined with latitude. Our results provide evidence that females have a significant effect on the genetic structure as predicted by theoretical models and provide support for the hypothesis that historical processes have modified the genetic structure of K. grandiflora.