Determination of an Effective Pollinator for the Rare and Endangered Urophysa rochkii and the Effects of its Floral Organs on Flower Visiting by Insects

Pollination is an important part of fertilization and reproduction in seed plants. Pollen movement largely restricts gene flow among individual plants and the manner of reproduction in a population, thereby affecting the genetic traits and fitness of plant offspring. For insect-pollinator-based plants, the flower-visiting characteristics, frequency and timing of the pollinating insects have decisive effects on the successful pollination of plants, whereas the colour and morphology of various floral components are important factors affecting the pollinating insects. Based on the pollination biology of plants, we studied the pollination mechanisms and links of Urophysa rochkii to understand its endangered status. Using U. rochkii at the full flowering period for the study, and using methods to observe, record, and perform experimental analysis, we recorded the species, frequency and flowervisiting time of these insects every 15 min and observed the effects of weather and temperature on the insects. Additionally, we captured the flowervisiting insects, brought them to the laboratory, and took photographs under a dissecting electron microscope for observation and identification. U. rochkii plants were grouped under different treatments that included removal of sepals, stamens and or pistils, while untreated plants were included as control group. In summary, the effects of floral components on the pollination process were examined. The experimental results showed that the effective pollinator of U. rochkii was Apis cerana Fabricius, and that sky-blue sepal was the most important factor affecting the flowervisiting frequency of the pollinators.