植物在对污染适应过程中对其它胁迫环境的适应性和进化潜能

（Project title: Response of toxic-metal-resistant plants to other extreme environments and their evolutionary potentials, Granted No. 39970142 ）.Environmental pollutants have been spreading all over the planet we live, which forms a novel environment that all organisms on the earth have never experienced and have to face up. It has well been realized that many plants are not adaptable enough to maintain themselves, leading to biodiversity loss and species extinction, but to what extents and how the pollutant-resistant plants will adapt non-pollutanted environments and evolve remain unknown. .Based on the same genetically original germ plasma, four populations of two strain Zea mays and Datura stramonium were respectively obtained that had continually grown in the similar polluted soil that was with high concentration of heavy metals for different durations, and the reference population were documented. This project investigated this series populations adapted polluted environments and extreme "natural"environments, and the experimentation dealing with relative competition between the different pollutant-resistant plants and reference plants was carried out, and genetic architecture and dynamics of genetic variations in different populations respectively exposed to toxic heavy metal for different durations were also studied with molecular ecological techniques, such as RAPD, SSR and ISSR. By integrating all the data from the investigation of quantative trait, eco-physiological parameters and molecular population genetic index, we preliminarily revealed the response of toxic-metal-resistant plants to other extreme environments and their evolutionary potentials..The results showed that, the plants that experienced longer duration of toxic metal pollution are more tolerant to the toxic metal they have been exposed, but they has lower resistance to any other natural environmental stress; the populations the experienced longer duration of toxic metal pollution are less competitive than the reference populations when they are both planted in the normal soils; genetic structure of the metal-polluted population in both Zea mays and Datura stramonium has changed compared with their reference populations; the genetic diversity in the population of Datura stramonium experiencing longer duration exposure to toxic metal pollution shows lower index, and decreases significantly, but this situation does not occur in Zea mays, and its genetic diversity index increases after a decrease phase. It is concluded that, plants will pay adaptation cost when they become able to survive in the polluted environments, and the cost eliminates its adaptability to other extreme environments; the decreased genetic diversity in wild plants indicates that the genetic plasticity tends to be less, and genetic predisposition gets lost, which leads to lose evolutionary potentials. It is reasonable to hypothese the lower comprehensive adaptability and evolutionary potentials will limits its niche breadth, and the globalised pollution will speed up the loss the biodiversity and the species extinction, but the reliable arguments need further investigation. .

以在重金属污染地区连续生长时间不同的曼陀罗和玉米各四个种群为对象，研究其对二氧化硫、紫外线等污染条件以及高温、低温、干旱及盐旱等胁迫条件的适应性；研究在常规无污染和竞争条件下各自的相对适应性；结合经历胁迫环境前后各种群的遗传变异性的变化，分析对污染具有一定适应性分化的植物对其它环境因素的适应性，探索污染适应植物的进化潜力。