Reproductive isolation and pollination success of rewarding Galearis diantha and non-rewarding Ponerorchis chusua (Orchidaceae).
Reproductive isolation and pollination success of rewarding Galearis diantha and non-rewarding Ponerorchis chusua (Orchidaceae).
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DOI：
10.1093/aob/mcq210
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发表时间：
2011
期刊：
影响因子：
4.2
通讯作者：
Hai‐Qin Sun;Bao-Qiang Huang;Xiao-Hong Yu;Y. Kou;De-Jun An;Yi-Bo Luo;S. Ge
中科院分区：
文献类型：
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作者：
Hai‐Qin Sun;Bao-Qiang Huang;Xiao-Hong Yu;Y. Kou;De-Jun An;Yi-Bo Luo;S. Ge
背景和目的越来越多的证据挑战了传统观念，即兰花是由于花或合子前隔离而导致花多样化的最明显的例子。关于共花植物之间的关系，特别是奖励和非奖励兰花之间的关系，很少有研究调查非奖励植物是否影响奖励植物的授粉成功。在此，研究了奖励兰花Galearis diantha和非奖励兰花Ponerorchis chusua之间的花隔离和相互影响。方法通过记录所选单株的开花和萎蔫日期来监测开花物候特征。传粉者池和传粉行为进行了评估，从实地观察。直接在田间测量花和传粉者的关键形态特征。通过人工授粉试验，对传粉者限制和种间亲和性进行了评价。在单种和异种样地调查坐果情况。关键结果该物种有重叠的开花高峰期。这两个物种的传粉者在访问每一个物种时都表现出一定程度的恒定性，但他们在降落在焦点兰花上之前也访问了其他花朵。一个很大的差异，在马刺大小的物种之间的沉积花粉的身体上的不同地区的共享传粉者。人工授粉实验表明，坐果强烈授粉限制在这两个物种。单种区和异种区的坐果率差异不显著。结论：机械隔离和不完全行为隔离相结合，消除了种间花粉传递的可能性。这些结果不支持促进或竞争假说附近的奖励花对非奖励植物的影响。非奖励性的朱氏拟步行虫对奖励性的朱氏拟步行虫没有显著的影响。diantha可以归因于两个物种的传粉者库之间的低水平重叠。
BACKGROUND AND AIMS Increasing evidence challenges the conventional perception that orchids are the most distinct example of floral diversification due to floral or prezygotic isolation. Regarding the relationship between co-flowering plants, rewarding and non-rewarding orchids in particular, few studies have investigated whether non-rewarding plants affect the pollination success of rewarding plants. Here, floral isolation and mutual effects between the rewarding orchid Galearis diantha and the non-rewarding orchid Ponerorchis chusua were investigated. METHODS Flowering phenological traits were monitored by noting the opening and wilting dates of the chosen individual plants. The pollinator pool and pollinator behaviour were assessed from field observations. Key morphological traits of the flowers and pollinators were measured directly in the field. Pollinator limitation and interspecific compatibility were evaluated by hand-pollination experiments. Fruit set was surveyed in monospecific and heterospecific plots. KEY RESULTS The species had overlapping peak flowering periods. Pollinators of both species displayed a certain degree of constancy in visiting each species, but they also visited other flowers before landing on the focal orchids. A substantial difference in spur size between the species resulted in the deposition of pollen on different regions of the body of the shared pollinator. Hand-pollination experiments revealed that fruit set was strongly pollinator-limited in both species. No significant difference in fruit set was found between monospecific plots and heterospecific plots. CONCLUSIONS A combination of mechanical isolation and incomplete ethological isolation eliminates the possibility of pollen transfer between the species. These results do not support either the facilitation or competition hypothesis regarding the effect of nearby rewarding flowers on non-rewarding plants. The absence of a significant effect of non-rewarding P. chusua on rewarding G. diantha can be ascribed to low levels of overlap between the pollinator pools of two species.