【作者】 曹文侠；

【导师】 王镜泉； 王兰州；

【作者基本信息】 西北师范大学 ， 植物学， 2001， 硕士

【摘要】 本研究从形态、生活史、种群垂直分布对策、生理生态等几个方面对东祁连山几种高寒杜鹃的生态适应对策进行了系统地研究。通过移栽分析了各生态因子的作用特点及几种杜鹃的适应差异。首次采用微弱电信号手段研究高寒杜鹃的适应性。在蛋白质、DNA水平上初步探讨了其适应对策的异同及机理，以配合物做探针研究植物DNA的电化学分析方法为首次使用。提出了东祁连山杜鹃花属植物保护和利用策略。 东祁连山杜鹃花属植物的适应对策体现在对寒冷以及由此引起的生理性干旱的适应上。1．植株矮小，生长较密；2．幼枝、叶和芽鳞外具密鳞片或厚角质，且分泌树脂粘液及挥发性精油；3．根分枝多而细密，集中分布于20cm的表层土壤中；4．土壤温度过低或冻结是造成杜鹃根系吸水困难、枝叶含水量下降、叶片反卷的根本原因；5．杜鹃枝叶年水分周期性变动与生理活动显著相关，叶片以不同方式和程度的反卷保存水分，以低含水量休眠越冬。6．生长季短暂，休眠期长，营养生长与生殖生长同步的短期集中生长对策，7月份为杜鹃一个生活周期中的关键，枝叶含水量达最大值，叶片无反卷，光合效率高，新枝生长量占全年的60～80％；7．几种杜鹃实生苗稀少，多以茎基萌生新枝来更替老枝或以根蘖繁殖新株；几种杜鹃在株形、叶面积、鳞片、叶质、叶反卷方式及程度、萌动时间、枝叶年水分动态，净光合积累时间等方面均显示，从千里香杜鹃、头花杜鹃、烈香杜鹃到陇蜀社鹃，其形态、生活史、生理生态适应对策的差异依次增大，且陇蜀杜鹃与其它三种社鹃的差异性更加明显。 东祁连山大阴坡几种杜鹃在不同海拔高度上的垂直分布对策是各物种生态位重叠与分离的结果：千里香杜鹃和头花杜鹃为海拔3300m以下梯度内的优势种。陇蜀杜鹃在海拔3300m以上更湿冷的范围内开始增加，并占绝对优势；烈香杜鹃在低处与千里香杜鹃和头花杜鹃伴生，在高处与陇蜀杜鹃伴生。 移栽后几种杜鹃不适应表现、叶片可溶性蛋白含量及适应性模型分析表明：移栽后的不适应是与原生境有差异的各种环境因子综合作用的结果，其中与原生境有巨大差异的温度因子可能是造成几种高寒杜鹃严重不适应室内盆栽条件的主要因素；从陇蜀杜鹃、烈香杜鹃、头花杜鹃到千里香杜鹃适应性依次递减。从高海拔向低海拔对烈香杜鹃与陇蜀杜鹃进行引种驯化有一定的希望，而千里香杜鹃和头花杜鹃由于适应范围小，难以实现驯化适应。几种杜鹃适应对策的微弱电信号研究也显示出了相似的结果，即陇蜀杜鹃对高温低湿环境的适应性也明显强于其它三种杜鹃，千里香杜鹃适应性最差。 通过Co（en）₃³⁺与DNA间作用的CV图、DPV图及△Ep/A₂₆₀值对几种杜鹃生态适应对策差异程度进行量化研究，其DNA电化学分析结果与形态以及生理上的分析结果相一致，即陇蜀杜鹃与烈香杜鹃、头花杜鹃的DNA差异较大，而后两者间差异较小，烈香杜鹃介于中间，这也反应出几种杜鹃生态适应对策在宏观和微观层次上的统一性。更多还原

【Abstract】 AbstractEcological adaptive strategy of four species Rhododendron in Eastern QilianMountains was studied systematically by the morphology, life history, verticaldistribution of populations and physiological ecology. Effect of ecological factorwas analyzed by transplanting. The adaptation of Rhododendrons was also studiedby a method of weak electric signal at first time. The similarities, differences andmechanism were discussed on the level of protein and DNA, at first time usingelectrochemical analysis in plant DNA, and complex as probe in it. A proposal ofprotecting and utilizing to Rhododendron in Eastern Qilian Mountains was bringforward.Ecological adaptive strategy of the four species of Rhododendron in EasternQilian Mountains reflected the adaptation to coldness and physiological drought.These feature as follows: 1. Plants grow low and dense. 2. There are squama andcutin on young branch, leaves and buds, excreting resin producing volatile oilfrom these organs too; 3. Roots grow slender and dense, distributing amongO?Ocm deep in the soil. 4. The too lower temperature or freezing of soil is mainreason that roots can not absorbing water easily, then water content reducing, andthe leaves began to roil reversely. 5. There is obvious interrelationship betweenperiodic variation of water content and physiological action; leaves keep water bycoiling reversely, spend winter by coiling tightly in shape of stick or canal. 6.Growing season is short, dormant period is long; vegetative growth andreproductive growth are synchronous during a same short period; July is the keymonth of life history of these Rhododendron species; water contents of branch andleaves get maximum value, leaves expansion without coiling, photosynthetic rateare higher, the growth of young branch is 60?0% of one year. 7. Rhododendronseedling is rare in the alpine shrub, the main propagation style are vegetativemultiplication by tiller. The young plant lives vigorously, which is the maincontributor of community biomass. There are some difference among four speciesin leaf area, density of squama. thickness of cutin, the pattern and degree, periodof sprouting, trend of water content, net photosynthetic rate, et.al. The differenceof morphology, life history and physiology increase from R. thym~folium and R.cap itatum, R. ant hopogonoides to R. prezewalski, and difference between R.prezewalsk and other three species are great.Overlapping and separation of niche can explain the vertical distributionstrategy of four Rhododendron species on elevation on northern slope of easternQilian Mountain. Below alt.3300m of the northern slope, it is occupied mainly by11R.thymzfolium and R. capitatum. R. prezewalskii become the dominant species up3300m, the cover of R. anthopogonoides get maximum at alt. 340Gm, associatedwith R. thym?folium and R. cap itatum downward, company with R. prezewalskiiupward.Adaptation behavior after transplanting, the soluble protein content in leaves,and model analysis shows that the unadaptation is the result of all factors that aredifferent with the original environment, but the temperature is the key factoraffected the success of potted indoors. Adaptability of R. thymjfolium, R.capitatum, R. anthopogonoides and R. prezewalskii are increasing by the order.The last two species of Rhododendron have hope of domestication. The sameresults had been gotten from the wake electric signal analysis in water culture ofRhododendron branches. R. prezewalskii is more adaptive to high temperatureenvironment than the other species of Rhododendron, The range of adaptation of R.thym~folium and R. capii~atum are weak.The difference of DNA of these Rhododendron species is the hereditary basisof similarities or differences in the adaptive strategy. The adapti更多还原