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The biological invasion destroyed the local ecosystem structure and function, resulting in the loss of biological diversity, has brought huge economic losses, and the threat to human health. As one of the important factors of global change, biological invasions caused widespread concern and attention in the past 10 years. However, alien species become invasive species mechanism has not been a more reasonable explanation, influence effectively predict and control invasive species. Therefore, the factors that can influence the invasion of alien species to carry out more research work. Guayule (Parthenium hysterophorus) for invasive plants of the Asteraceae, native to southern North America, Central America, West Indies, South America, Central; international hemlock. Its crazy growth, the rapid spread of toxic allelochemicals have a great threat to the crop yields, biodiversity and human health. The weed has a wide range of ecological adaptability and strong reproductive capacity, and in recent years has developed into a more serious harm of invasive alien plant. This article through the field fixed-point observation, artificial control experiments, guayule in different habitats flowering material climate, population flowering seed quantity characteristics, biomass and its allocation, reproductive processes conducted a study, comparing silver parthenium populations in different habitats in different seasons the ability to reproduce. In addition, we also studied the guayule different N, P nutrient levels the ecological adaptability as well as in different light levels adaptability. Designed to reveal the the guayule invasion ability and invasion mechanisms provide the basis for the prevention and control of guayule. The main findings are as follows: (1) guayule breeding season is long, so that it can generate a large number of seeds and seedlings in a relatively short period of time will be able to eruptions and intrusion. Grassland, woodland and roadside habitats have from March to October, the guayule plant growth, flowering and fruiting, both from the end of April, early May to October. Arable land, from March to December, guayule have plants, both flowering and fruiting from May to December. (2) guayule populations of different habitats in different seasons, flowering and fruiting number of different characteristics, different reproductive capacity. In the grass, woodland and roadside habitats, autumn flowering plants, the number of branches, number of capitulum over the summer and spring, the number of seeds produced by the fall of the reproductive capacity of the three habitats guayule strongest period. In arable land in the winter, the number of branches and the number of capitulum than in summer and autumn, the seed yield accordingly. Therefore, the strongest the winter reproductive capacity arable land. Fall, guayule in four habitats of the size of the reproductive capacity as follows: arable gt; grass gt; roadside gt; open forest. Farmland in guayule population density, the smaller the number of branches and the number of capitulum, seed setting rate and seed weight and seed yield up to the strongest, the ability to reproduce; grassland population density, the number of branches and the number of capitulum high seed yield, followed by the ability to reproduce; roadside number of flowering plants, the number of branches, but the number of capitulum seed setting rate and seed weight, seed yield less than the grass; small open forest population density, The fewer the number of branches and the number of capitulum lowest seed yield, but its high quality seed. Overall, guayule ability to reproduce in the habitat study are extremely powerful. 1 guayule seed setting rate and seed in 2008 and 2009 in the same habitat grain weight no significant differences. Capitulum open forest and road spurious environment, different year, seed yield no significant difference between the two habitats guayule may be less affected by human ability to reproduce small changes. But in open grassland and farmland habitats capitulum number of different years, seed yield were significant differences between the two habitats due to grazing and farming activities, guayule by the impact, changes in the ability to reproduce. (3) guayule biomass allocation ratio by adjusting the various components to adapt to different habitat conditions. Meadows and roadsides, increasing the proportion of root biomass to compete underground resources; increase the proportion of stem and leaf biomass in open woodland, to improve the light acquisition rate; arable land, increase the proportion of root biomass competition underground resources, and increase the proportion of leaf biomass to compete on the light. Component biomass of the breeding season, and the environment is closely related to and affected by plant density and height constraints. Showed high morphological plasticity, and the plant has a strong invasion-related biomass allocation in the various components of the different habitats in different seasons. (4) guayule reproduction to sexual reproduction, floral and a shorter period of time, in June, from bud to fully mature seeds only 22 days. Pollen grains are tapered spikes projections, easily adhere to the insect-borne, histochemical mainly starch-containing loose mainly at 9:00-13:00 This strong activity, pollen / ovule ratio (P / O) . The stigma receptivity five days and the best pollination stigma extended period of the second and third day 9:00-13:00. Self-incompatibility, there is no apomixis phenomenon belongs to the type of outcrossing breeding system, you need to pollinators, intrusion habitats some common insects for their pollination higher rate of natural seed. 5 main pollinators including black edges Hymenoptera bees, small bees, black bees and Diptera Musca domestica, Lucilia, the peak of flower-visiting basic focus 10:00-13:00. (5) guayule showed adaptability to different soil nutrient levels. Within a certain range, the the guayule root biomass ratio decreases with increasing nitrogen, total biomass, leaf biomass than (LMR), floral biological than (FMR), leaf area index (LAI), total leaf area (TLA), leaf area ratio (LAR), relative growth rate (RGR), number of branches, capitula number increases with the increase in the level of nitrogen nutrients; For phosphorus nutrients, leaf mass ratio, leaf area The ratio of the total leaf area, relative growth rate increased with increasing phosphorus levels; no significant change in total biomass, leaf area index, number of branches, capitulum number of various phosphorus levels. Increased soil N increased seed yield, soil P guayule improve seed quality. Of N, P nutrients have different adaptability. (6) The guayule not survive in the light intensity of less than 5% of the habitat, but can adapt to Change the light environment (22% -100%) by adjusting the total biomass, root mass ratio, leaf than flower biomass ratio, total leaf area, leaf area than to adapt to different light intensities. The results of the study showed that, guayule has a strong reproductive capacity, and different in different habitats in different seasons reproductive capacity, the weeds also has a wide range of ecological adaptability. It should be noted that the invasion and control strategies in different habitats in different seasons.
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