Sex Expression And Pollination Characteristics In Eurya Loquaiana Dunn

The genus of Eurya Thunb. was described as strictly dioecious, and the gender variation was an extremely rare phenomenon in existing research data. But it occasionally appeared that reported gender variation phenomena in the Eurya species. Gender variant individuals could be as an important material to study ecological evolutionary adaptation mechanisms and gender on this genus.Gender variation has been found in Eurya loquaiana during the field investigation. The main objects of this paper were to accumulate some data for the study of the gender expression and the differentiation of Eurya, and then provide further some reference for the evolution of bisexual flowers and unisexual flowers and illuminate sex differentiation and sex evolutionary pathways of Eurya. The research on Eurya loquaiana which using the methods of morphology and reproductive biology, was applied in the following four aspects:1. the sex expression law in Eurya loquaiana,2. flowering phenology in Eurya loquaiana,3. pollination characteristic in Eurya loquaiana,4.gender allocation in Eurya loquaiana. The results were obtained as follows:1. Eurya loquaiana had six types of flowers:pistillate flower, staminate flower, pistillate flower with staminode, staminate flower with pistillode, hermaphrodite flower, sterile flowers. From the level of single flowers, the genders of Eurya loquaiana were female, male, and bisexual. To the contrary, the Eurya loquaiana gender embodied at the plant level was more complicated. There were six gender types in Eurya loquaiana: gynoecius, androesious, gynomonoecy, andromonoecy, monoecious and trimonoecious. In wild populations, gender variant plants were rare; typical dioecious plants were common yet. Therefore, the population had different gender combinations. In no gender variant plants population, their sex could be directly described as dioecious. For populations including gender variants, gender expression became too complex to describe easily.2. Eurya loquaiana flowered in the autumn with a flowering of a week or so, the entire flowering duration was shorter. Overall, Eurya loquaiana was a species with small but massive blossoms and high flowering synchronicity. The gender variant plants had many characteristics (flower bud, corolla and size) between the male and the female. The Gender-bending flower pollen grains per flower and pollen visibility, was obvious not equal to the male flower. And ovule number per flower and nectar volume per flower was significantly weaker than the female flowers. It reflected that gender variant plants fitness was lower than the typical male plant and female plant. On gender variant plants, bisexual flower, male flowers and female flowers had similar pollen counts, pollen visibility, ovule number per flower, nectar volume per flower, those proved that the fitness of each flower were quiet.3. Eurya loquaiana pollination was given priority to with entomophilous, while wind-pollinated played a minor role. The pollination insects were mainly the hymenoptera and diptera insects. Among them, there were three families, four genera and four species in Hymenoptera, two families, four genera and five species in Diptera. Apis (Sigmatapis) cerana cerana Fabricius and Bombus (Rufipedibombus) eximius Smith were main pollinators, their pollination behavior on different gender paints was different. They feed pollen on the male plants, sucked nectar on female plants, and visited the male plants more often.4. As for module biomass allocation of Eurya loquaiana, stamens biomass allocation in male flowers (in the male plants flowers and gender variant plants) was less than pistil biomass allocation in the female flowers(in the female plant and gender variant plants). Bisexual flowers, the stamens biomass distribution below the pistil biological allocation. In bisexual flowers, the stamens biomass allocation was less than the pistil biomass allocation.According to the morphology of the flowers of gender variant plants and its sex function, it could be inferred that the changing process of flowers in gender variant plants were as:pistillate flower to pistillate flower with staminode, bisexual flower to staminate flower with pistillode, staminate flower. According to the current approach that has been proven to five ways of dioecious evolution, it could be speculated that the evolution of Eurya dioecious species maybe to experience the phase of gynomonoecy. Among forty-one gender variant plants, with the most proportion of gynomonoecy, corresponding to that it is. Some studies have shown that the gender pattern of dioecious plant within their populations will be changed under the influence of drought stress, which will increase the amount of male plants, that resulting in the decline in the proportion of male and female. The flower change process in gender variant plants indicated that there was a general tendency that gender variant plants would be transformed into male plants. The gender variant plants could be transformed into male plants if the change constant, ultimately increase in the number of male plant, male and female proportion to drop, but the continuous observations for many years were required. The gender-bending phenomenon of Eurya loguiana has been observed only in short-term and part, in this study. It is unknown whether the gender will changeover time and the environment; thus further studies are needed. The obvious differences which exist between male and female plants, reflects its ecologicaladaptability of the dioecious system. The evolution of the differences between the sexes could have close relationship with gender evolution, but the differences appear before or after gender evolution is not clear, so relevant problems need to be researched.