Relationship of pollination ecology to population genetic structure and speciation rates in Justicia (Acanthaceae)

点击翻译按钮获取中文摘要

Divergent behaviour of different pollinating agents in terms of pollen carry-over and distances covered is expected to result in different degrees of gene flow between populations. This would then lead to differences in population genetic structure between populations with different pollination syndromes, and ultimately in divergent speciation or extinction rates. This hypothesis, however, has never been effectively tested.In the proposed study, all three links of the presumed causal chain ¿ pollination, population genetic structure, diversification rates ¿ will for the first time be examined together. The chosen study group is New World Justicia, a monophyletic group containing bee and hummingbird pollinated representatives. Pollination experiments with dyed pollen will be conducted on three melittophilous and three trochilophilous species to test the hypothesis of differences in pollen flow. A molecular analysis of three melittophilous and three trochilophilous species will be conducted to test the hypothesis of differences in population genetic structure. Subsequently, a sequence-based phylogenetic analysis of New World Justicia will be conducted to test the hypothesis of consistently divergent diversification rates in sister clades with different pollination syndromes.