Historically, dichogamy, the temporal separation of male and female function in flowering plants, has been interpreted as a mechanism for avoiding inbreeding. However, a comparative survey found that many dichogamous species are self-incompatible (SI), indicating dichogamy evolved for other reasons. Here we reexamined the association between dichogamy and SI in a phylogenetic framework and tested the hypothesis that dichogamy evolved to reduce interference between male and female function. Using paired comparison and maximum likelihood correlation analyses, we found that protandry (male function first) is positively correlated with the presence of SI and protogyny (female function first) with self-compatibility (SC). In addition, estimates of transition-rate parameters indicated strong selection for the evolution of SC in protogynous taxa and a constraint against transitions from protandry to protogyny in SC taxa. We interpret these results as support for protandry evolving to reduce interference and protogyny to reduce inbreeding.
Published Article/Book Citation
Matthew B. Routley, Robert I. Bertin, and Brian C. Husband. "Correlated Evolution of Dichogamy and Self‐Incompatibility: A Phylogenetic Perspective." International Journal of Plant Sciences (2004) 165:6, 983-993. 10.1086/423881
Routley, Matthew B.; Bertin, Robert I.; and Husband, Brian C., "Correlated Evolution of Dichogamy and Self‐Incompatibility: A Phylogenetic Perspective" (2004). Biology Department Faculty Scholarship. 8.