中国濒危苔类植物囊绒苔属的保护生物学研究

So far, there isn’t all-round and systemic research about a single species ofbryophyte in the world. This project had primarily chosen a rare and endangered.Hepaticae of China, Trichocoleopsis, but they couldn’t be found because the.environment of their habitat had been worsened. We asked the council of NSFC for.instructions, then used another endangered bryophyte, Dolichomitriopsisdiversiformis, as a substitute of experimental material. The main research content and achievement are as follow.1. The natural distribution and the habitat characteristics of this species wereinvestigated in detail, its natural distribution area and the variation index of theecological factors in the habitat were also quantitatively and systematically checked.2. By using tissue culture method and optical microscope technology, We studied.the effects of light and temperature on the spore germination and protonema.development of Dolichomitriopsis diversiformis, the results shown that light is themajor environmental factor that affects the spore germination and temperature themajor factor that affects the protonema development.3. The experiments of ex situ conservation of this species were carried outsuccessfully. The moss plants of this species in 75% of the explanting spots and more.than 60% of explanting area have survived and fulfilled its life cycle.4. By using CI-301PS, we studied the influences of light intensity, temperature and water content on the photosynthetic rate, and established a mathematical model.that describes the optimums of light, temperature and water content for this moss’sphotosynthesis. The statistics test showed that this model is credible..5. By setting some stable measuring spots in the field, we measured the.photosynthetic rate, dark respiration rate, water transpiration rate and water useefficiency of the species under the natural conditions, and analyzed their seasonchanges and diurnal changes in these two years.6. We experimented the esistance of three species of mosses (include.Dolichomitriopsis diversiformis) to high temperature stress, measured the changes of membrane permeability and protective enzymes (include peroxidase and SOD).activity under high temperature stress, and the results showed that the high lethal temperature is about 40.67℃, which is lower than general mosses’ 42~47℃..7. The characteristics of state transition and fluorescence spectra of.Dolichomitriopsis diversiformis at 77K, induced by different spectra of light, were measured by fluorescence analysis in vivo. The results showed that a significant difference existed between the moss and other higher plants in the structure of photosystems, and the former adapted better to the spectrum changes of low light.8. Two aspects of the genetic diversity, i.e., organ morphology and DNA analyses of leaves of Dolichomitriopsis diversiformis, from different locations were studied.The results indicated that mutation of the morphology of leaves was highly correlated to ecological conditions. The moss had high RAPD mutation and DNA diversity.and a complicated genetic background. However, the gradual extinction of this.species was not directly due to its genetic diversity.9. In conclusion, it is primarily considered that the internal factors render Dolichomitriopsis diversiformis. The moss to nearly extinct, such as low ecological adaptation, requiring strict surviving conditions, vulnerable to adverse environment.(in particular high temperature), low in net photosynthetic rate, photosynthetic.saturation, growth rates and population, and undesirable natural renewal. In addition,the human activity damaging its inhabiting environment is an external factor.The following protective strategies for Dolichomitriopsis diversiformis are.therefore recommended: to entirely protect and maintain its inhabiting environment,.including its migration of habitant; to promote diversification and to increase.ecological adaptation by exploring its high potential of

首次对东亚特产濒危苔类植物囊绒苔属群的分布、数量、能量结构和生理生态学、繁殖生物学以及遗传多样性等进行系统的实验研究，建立含有环境因子参数的种群动态模型，并结合种群生存力分析,探明种群濒危机制及其成因，提出防止和控制濒危种群绝灭的保护策略及.有效措施。本项目对我国苔藓植物保护生物学研究赶超世界先进水平具有开创性意义。