EVOLUTION OF PLANT POLLINATION SYSTEMS - HYPOTHESES AND TESTS WITH THE NEOTROPICAL VINE DALECHAMPIA
EVOLUTION OF PLANT POLLINATION SYSTEMS - HYPOTHESES AND TESTS WITH THE NEOTROPICAL VINE DALECHAMPIA
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DOI：
10.1111/j.1558-5646.1993.tb02170.x
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发表时间：
1993-10-01
期刊：
影响因子：
3.3
通讯作者：
ARMBRUSTER, WS
中科院分区：
文献类型：
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作者：
ARMBRUSTER, WS
对新热带区的40种Dalechampia L.进行了系统发育研究，并结合授粉和交配系统的研究结果进行了分析。（大戟科）重建传粉系统的进化变化的历史。该分析的结果被视为一种假设，并在数据集发生变化时检验循环性问题和稳健性。历史假说被用来对授粉生态学和奖励生物化学的细节做出具体的预测;这些预测得到了独立观察的支持。我的结论是授粉系统在Dalechampia进化不稳定，相对于大多数形态特征，重复的平行和反转。Dalechampia进化出的三个授粉系统之间的过渡（由树脂收集蜜蜂授粉，收集芳香的雄性euglossine蜜蜂和花粉收集蜜蜂）已经促进了生物化学exaptation（预适应）。由雄性Euglossine蜜蜂进行的花粉传播在该属中相对罕见，但已经独立起源了三到四次。相比之下，采集树脂的雌蜂授粉非常常见，但只有一次起源。授粉系统之间86%至97%的转换涉及一个中间阶段，在此期间新旧传粉者都是有效的，但3%至14%的转换可能是“瞬时的”，缺乏中间阶段。分泌树脂奖励的物种分支是分泌香味奖励的物种分支的10倍;间接证据表明，不同的灭绝率可能是造成这种差异的原因。相对异花授粉（异花授粉）的物种已经从更多的自花授粉（自花授粉）物种进化了13次，而自花授粉的物种已经从更多的异花授粉物种进化了11次。在受干扰的生境中出现的物种是兼性自花受精的，而在未受干扰的生境中出现的物种通常是高度异花受精的。
The results of pollination and mating-system studies were integrated with a phylogenetic study of 40 Neotropical species of Dalechampia L. (Euphorbiaceae) to reconstruct the history of evolutionary change in pollination systems. The results of this analysis were treated as a hypothesis and tested for circularity problems and robustness in the face of changes in the data set. The historical hypothesis was used to make specific predictions about details of pollination ecology and reward biochemistry; the predictions were supported by independent observations. I conclude that pollination systems in Dalechampia have been evolutionarily labile, relative to most morphological features, with repeated parallelisms and reversals. Transitions among the three pollination systems evolved by Dalechampia (pollination by resin-collecting bees, fragrance-collecting male euglossine bees, and pollen-collecting bees) have been facilitated by biochemical exaptation (preadaptation). Pollination by male euglossine bees is relatively rare in the genus but has originated independently three to four times. In contrast, pollination by resin-collecting female bees is very common, but has originated only once. Eighty-six to 97% of transitions between pollination systems involved an intermediate phase during which both old and new pollinators were effective, but 3 to 14% of transitions may have been ''instantaneous,'' lacking the intermediate phase. Clades of species secreting resin rewards are about 10 times as species rich as clades of species secreting fragrance rewards; circumstantial evidence suggests that different extinction rates may be responsible for this difference. Relatively allogamous (cross-pollinating) species have evolved from more autogamous (self-pollinating) species up to 13 times, and autogamous species have evolved from more allogamous ones up to 11 times. Species occurring in disturbed habitats are facultatively autogamous, whereas species of undisturbed habitats are often highly allogamous.