Population Structure Of Eurya Loquaiana And Regularity Of Sex Variation Reflected On Floral Morphogenesis

Dioecious plant is a normal type of the vegetable kingdom, generally considered dioecious plants are evolved from Hermaphroditic, Study of sex expression、evolution and variation of dioecious plants are important parts of the evolution of plant sex.Eurya loquaiana Dunn belongs to Theaceae, Eurya Thunb. Existing studies shows that Eurya are dioecious plants, and it reported that Eurya species occur sex variation infrequently.Gender-variant plants appear in Eurya are important materials of studying sex evolution and ecological adaptation mechanism of Sex system in Eurya.Outdoor investigation found Eurya loquaiana population in Jinyun mountain appear sex variation. To accumulate study datas of sex evolution and population evolution of Eurya, and have further studies of sex evolution and sex evolutionary pathway of Eurya, and to provide a reference for evolution of bisexual flowers and unisexual flowers in the plant kingdom. In this paper, we use methods of plant population ecology, morphology and other disciplinary approach, study the following aspects of Eurya loquaiana: sex ratio, age structure, spatial distribution pattern, the evolution of flowers of sex variation plants.Zoned 7 quadrats in area that grows many Eurya loquaiana plants in Jinyun Mountain, additional survey some plants out of quadrats. Identify sex of each plant,measured basal diameter of the plants to reflect its’ age, marked the location of the plant, use Ripley’s L function to analysis spatial distribution.Collected blooming flowers, with FAA fixative saved for later in the indoor anatomical analysis. Saved in the FAA fixative for indoors anatomical analysis later.Calculated sex ratio, draw profile according to the location of the plants in the quadrats. Using base diameter represent age, all basal diameter per plant as a 10 mm diameter class is divided into 14 age level and make age charts,then analysed age structure types of Eurya loquaiana population.Flowers collected in the field were anatomized, measuring ent of pistil length and width of the ovary, stigma crack number, number and length of stamen, anther length, and useing these indicators to characterize the flowers and the level of sexual orientation.Then comparing the morphological changes of the floral patterns of the different age and sex, exploring the law of the change of floral pattern with time. The ratio of Eurya loquaiana sex variation plants is Small, male plants and female plants is majority.Research results show that there were 367 individuls, in which the female plant were 161, male plants were 100, gender variant strains were 52, dwarfs that couldn’t distinguish gender were 54. The sex ratio(female/male=1.61) of all plants was significantly deviated from 1:1, and the female plants were more than male in all plots. The sex ratio showed that Eurya loquaiana environmental pressure was small, and Jinyun Mountain habitat was suitable for Eurya species survival.In the view of age structure, the numbers of plants of 10-20 mm, 20-30 mm, 30-40 mm are large, the numbers of larger diameter plants are in descending order. Eurya loquaiana population belonged to the type of growth and the quantity decreased with the increasing age, but in seedling stage age class of trees was significantly less than that of the larger age class of trees, which may affect growth potential of the population. Data shows that the smallest diameter class 3 sex ratio close to 1:1, and the sex ratio of larger 5 diameter class close to more female.Spatial distribution pattern analysis showed, Eurya loquaiana plants in different plots and different spatial scales presented aggregated distribution, random distribution and uniform distribution. The difference of the distribution pattern may be due to the narrow area of investigation. It can be seen that the main distribution type were random distribution and aggregation distribution, partial to aggregated distribution at smaller spatial scales. Eurya loquaiana fruits are small, no animal feeding, seeds testa hard, so their communication ability was limited. Eurya loquaiana was an important component shrub layer of evergreen broad-leaved forest of Jinyun Mountain, Eurya loquaiana plants was relatively low, and was difficult to spread very far in the dense forest seed, which may be the cause of Eurya loquaiana aggregated distribution on a small spatial scales.Form datas of flowers,we can see with the decrease of basal diameter, Eurya loquaiana sex evolution plants’ pistil length show the trend of separation, that is, there are short and long pistil pistil of flower formation; ovary width becomes more sample; flowers of stamens length of 0(ie female) increased, another length of stamens in other flowers tended to increase, that the evolutionary trend of stamens with time becomes longer or is not; anthers trends similar as stamens, become longer and be more female flowers without anthers, evolutionary trend of the anthers is becoming longer or not. It can be speculated the evolution of single flower of Eurya loquaiana sex evolution plants from one form to two forms, namely that evolution of Eurya loquaiana sex evolution plants may form dioecious flowers plants. Sex ratio of each diameter class shows 30-40 mm diameter and larger four-level male plants ratio decreases, and the number of plants of various types sex reflected andromonoecious same strain is second only to the number of hermaphroditic plants type, speculat that gender mutant evolution over time may be imperfect pistil of having male flowers �'male flowers with imperfect pistil�'bisexual flowers�'female flowers with imperfect stamens�'female flowers. This inference is correct or not, needs further proof.