贠建全:广东荷包岛维管束植物名录

以分布于秦岭的金花忍冬（Lonicera chrysantha Turcz.）、忍冬（L.japonica Thunb.）、葱皮忍冬（L.ferdinandii Franch.）和金银忍冬（L.maackii（Rupr.）Maxim.）为对象，通过定位观察、人工授粉实验、人为设置实验斑块的方法对忍冬属4种植物的开花生物学特性、繁育系统、花色变化现象、传粉过程进行了研究。结果表明，4种植物的单花花期、花部特征存在差异。人工授粉实验显示，4种植物均存在一定的花粉限制，自交不亲和。除葱皮忍冬外，其余3种植物随着花色由白变黄，花粉和花蜜报酬减少、雌雄生殖能力逐渐降低；葱皮忍冬花变色后花蜜量变化不显著，且仍保留较强的雌性生殖能力。变色花的保留被认为是植物的一种生殖策略，通过增大植物的花展示来扩大自身的吸引力，以吸引更多远距传粉者访花。人为控制白、黄花不同数量比的实验结果表明，大多数传粉者偏向访问白花（变色前的花），且白花提供的报酬量和黄花（变色后的花）数量显著影响传粉者的访花频率，即当花蜜量减少或黄花数量增多时，传粉者访花频率随之降低。因此，我们认为忍冬属4种植物的花色变化可能除了增大植物对远距传粉者的吸引力外，对近距传粉者的访花行为也可能具有一定的影响。当传粉者接近植株时，变色后的花可能暗示其花蜜（花粉）报酬已经发生变化，并驱使昆虫离开并飞向同株或异株植物新开放的报酬丰富的白花，这既有利于提高传粉者的觅食效率，又能降低植物同株异花授粉的几率，对忍冬属植物及传粉者都具有重要意义，是植物长期与授粉昆虫相互适应的反映。

Study on the breeding system and floral color change of four Lonicera species in the Qinling mountains

We examined the floral biology, mating system, flower color change, and pollination process of Lonicera chrysantha Turcz., L. japonica Thunb., L. ferdinandii Franch. and L. maackii (Rupr.) Maxim. from the Qinling mountains via field observation, artificial pollination experiments, and artificial experimental patches. Pollen limitations and some differences in single-flower flowering and floral traits were observed among the species, which were all self-incompatible plants. Except for L. ferdinandii, all species changed their corolla color with decreasing pollen/nectar rewards and lost both male and female reproductive abilities. The nectar reward in L. ferdinandii did not alter significantly, and it retained strong female reproductive function. The retention of post-color change flowers might be a reproductive strategy of plants, in which an increase in floral display enhanced attractiveness to pollinators. The artificial control experiments showed that most pollinators preferred to visit the white flowers (pre-change flowers), and the amount of reward and number of yellow flowers (post-change flowers) significantly impacted pollinators' access frequency. That is, access frequency decreased with nectar reduction or increase in yellow flowers. These results indicate that flower color changes might increase plant attractiveness to distant pollinators, or have a certain influence on nearby pollinators. The post-change flowers might play a role in signaling to pollinators during their approach that the reward of nectar or pollen had changed, thus re-directing the insects to the sufficiently rewarded white flowers of homophyletic or heterologous plants. This could improve both the foraging efficiency of pollinators and reduce the chance of geitonogamy, which has important implications for the Lonicera species and their pollinators. These results show the reaction of plants and pollinators to long-term mutual adaptation.