Pollination Biological Research Of Hydrilla Verticillata

Hydrilla verticillata is a perennial submerged plant of Hydrilla Rich,which is widely distributed in ponds and lakes in China.As a submerged plant,its reproduction process is closely related to the water environment.Previous studies have shown that Hydrilla verticillata is pollinated by water,but the specific pollination process of Hydrilla verticillata is not clear.In this study,we studied the pollination biology of Hydrilla verticillata,and observed the morphological structure of their reproductive organs.The paper studies the pollination process and pollination results of Hydrilla verticillata by observing it's florescence and flowering phenology,analyzing the pollination process and result of pollination.The main results are as follows:1.The structure of female and male flowers of Hydrilla verticillata is very different,male flowers growth under water and open on water surface,female flowers can open on water surface or underwater,when they open under the water,they are covered by bubbles,and they are concave in the water surface,the center of the depression is stigma region.In addition,the pollen surface of Hydrilla verticillata has obvious microspike structure,which can help the pollen float on the water surface for a long time without sinking through hydrophobic interaction.2.The florescence of Hydrilla verticillata is August to October,Hydrilla verticillata is dioecious plant,male flower bloom before female flower,when the male flower float out of the water surface,the pollen is release on the water surface.Female flowers bloom under water,with the help of bubble growth to the surface of the water and make a depression.The depression capture the pollen which flowed on the water surface and complete the pollination when reach the center of the female flower stigma,pollination process is completed in a day,and then the female sink into the water and bear fruit.When Hydrilla verticillata is in the natural state,pollinated rate is very high,the seed setting rate can reach about 76.1%.From these experimental results,we found that the pollination of Hydrilla verticillata is confined to the water surface and belongs to two-dimensional pollination.Due to the dispersal of pollen on the surface of water and the trap structure of female flowers,Which make the water-pollinated plant Hydrilla vertiilata hats a high success rate of pollination.The two-dimensional pollination of Hydrilla verticillata is very different from the known two-dimensional pollination,and these differences are mainly reflected in the form of dispersal form,which is closely related to the morphological structure of female and male flowers of Hydrilla verticillata.These conclusions not only help us understand the pollination process of Hydrilla verticillata,but also help us to make more understand to the evolution of hydrophyte pollination.