Ecological and genetic differentiation among parapatric populations of bumblebee-pollinated plants.

花冠管的长度表现出地理变异，与两种熊蜂授粉种的喙长度相对应。我们推测，授粉者群落中的海拔差异是影响野生野生稻种群形态和遗传分化的主要因素。花冠管长度的分化可以用高度差异来解释。然而，两种熊蜂的访问频率在不同的年份是不同的，授粉效果并不取决于花冠长度和熊蜂口器之间的对应关系。遗传距离可用两种熊蜂的高度分化和相对频率来解释。这些结果表明，在不同的海拔范围内，五味子发生了花序和遗传分化，花冠管长度的高度跃变是长花冠和短花冠种群二次接触的结果。

The corolla tube length of Isodon shikokianus shows geographical variation, corresponding with the proboscis length of two bumblebee pollinator species. We hypothesized that altitudinal variation in the pollinator assemblage is a principal factor mediating morphological and genetic differentiation among I. shikokianus populations. The differentiation in corolla tube length was explained by altitudinal difference. However, visitation frequency of two bumblebee species vary among years and pollination effectiveness do not depend on correspondence between the lengths of the flower corolla and the mouthparts of the bumblebees. Genetic distance was explained by altitudinal differentiation and relative frequency of two bumblebee species. These results suggest that floral and genetic divergence of I. shikokianus occurred in different altitude range, and the altitudinal cline of corolla tube length was a result of secondary contact between the long and short corolla populations.