【作者】 马成仓；

【导师】 高玉葆；

【作者基本信息】 南开大学 ， 环境科学， 2004， 博士

【摘要】 内蒙古高原有锦鸡儿属植物16种，它们分布于东起呼伦贝尔草原西至阿拉善荒漠、气候和植被呈显著梯度变化的广大区域，并呈现自东向西随着干旱化程度的增强、从森林到草原到荒漠，种类逐渐增加趋势。为了揭示内蒙古高原锦鸡儿属植物生态适应特性与地理分布关系的生物学基础，本文对内蒙古高原不同类群、不同种、不同种下类型、不同种群锦鸡儿属植物的地理分布、生长发育、形态结构、光合机构、渗透调节、水分代谢、光合特性和保护酶系统进行了比较研究。研究结果表明：(1)内蒙古高原锦鸡儿属植物的形态、结构和生理特性与它们分布区的光、温、湿条件相适应，这是锦鸡儿属植物地理分布的生物学基础。(2)锦鸡儿属植物是以形态变异、完善的水分调节功能、低蒸腾和高水分利用效率、光合特性、光合机构和抗氧化系统的变异来适应它们的环境的。(3)羽状叶的代表植物--小叶锦鸡儿适应在半干旱地区生活，假掌状叶的代表植物--狭叶锦鸡儿适应在半干旱至极干旱地区生活。狭叶锦鸡儿比小叶锦鸡儿对干旱、高温、强辐射的适应性强。这一研究结果可以作为羽状叶是原始类群、假掌状叶是较进化类群观点的证据。(4)分布于荒漠区的锦鸡儿植物对环境的适应方式不同，柠条锦鸡儿、狭叶锦鸡儿和垫状锦鸡儿以强保水能力，维持稳定的水分而适应，而荒漠锦鸡儿可能以对水分变化的强耐性而适应。(5)小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿在内蒙古高原自东向西形成一个地理渐变群。分析内蒙古高原的气候变迁和小叶锦鸡儿、中间锦鸡儿及柠条锦鸡儿的分布状况认为，小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿地理连续渐变群是适应环境演化的结果。(6)在适应环境的进化过程中，中间锦鸡儿种内出现明显变异，形成两种表现型，即绿叶型和灰叶型。(7)从物种发生关系来看，中间锦鸡儿位于小叶锦鸡儿和柠条锦鸡儿之间，且绿叶型中间锦鸡儿与小叶锦鸡儿相近，灰叶型中间锦鸡儿与柠条锦鸡儿接近，其演化过程是小叶锦鸡儿--绿叶型中间锦鸡儿--灰叶型中间锦鸡儿--柠条锦鸡儿。(8)内蒙古高原锦鸡儿属植物种群间发生明显的遗传分化，表明它们对环境的适应是有分子基础的，是以遗传变异为基础的种群分化适应。(9)内蒙古高原锦鸡儿属植物的一些光合和水分代谢特性的形成与水分状况有关。(10)内蒙古高原锦鸡儿属植物叶片形态结构与生理生化功能相适应。(11)一些特性的研究表明，分布于荒漠区的锦鸡儿种和种群虽然有多种特点来适应环境，但它们的适应能力是有限的，环境胁迫可能超越其限度。总之，内蒙古高原锦鸡儿属植物对变异的生活环境的适应与类群分化、种间分化、地理渐变群形成、表现型分化、种群分化密切相关。这些分化表现在外部形态、生理功能和基因构成上，显示出优化的结构、功能和经济的资源利用。这是内蒙古高原锦鸡儿属植物地理分布的生物学基础。更多还原

【Abstract】 There are 16 Caragana species in Inner Mongolia Plateau and they are found over a vast area of land (from the east in Hulunbeier grassland, 125 E, to the west in Alashan desert, 98 E), which varies with climate and vegetation along longitudinal series. The number of species within the genus Caragana increases following the environmental gradient from the east to the west, or from forest to grassland and to then desert. In order to explore the biological basis for the geographical distribution of these Caragena species, a comparative study was conducted within and between the species in respect of growth and development, morphology structure, photosynthetic apparatus, osmotic adjustment, water metabolism, photosynthetic characteristics and protective enzymes. The results of the study are shown as follows: (1) The morphological structure and physiological characteristics of Caragana species were in adaptation to solar radiation, air temperature and humidity in their own habitats, and these were responsible for the geographical distribution of the Caraganna species. (2) The Caragana species were adaptable to their environment by means of morphological variations, water adjustment, lower transpiration, higher water use efficiency, and variations in carbon assimilation characteristics, photosynthetic apparatus and protective enzyme system. (3) The representative species of the pinnately compound leaf group - C. microphylla adapted well to the semi-arid climate, while the representative species of the pseudo-palmately compound leaf group- C. stenophylJa well adapted to semi-arid and intensively droughty climate. C, stenophylla was more adaptative to drought, high temperature and intensive radiation than C. microphylla. This provided an evidence for the viewpoint that the pinnately compound leaf group was primitive and pseudo-palmately compound leaf group was relatively advanced. (4) The adaptation strategy of the Caragana species in the desert region differed from each other: C. korshinskii, C. stenophylla and C. tibetica relied on stronger water holding ability, while C. roborovskyi relied on stronger ability of enduring water content variations. (5) C. microphylla, C. davazamcii and C. korshinskii formed a geographical cline in Inner Mongolia plateau. Taking into account the climate change of Inner Mongolia Plateau and the geographical distribution of these three species, it seeded to be reasonable to conclude that the formation of this geographical cline was the consequence of plant adaptation to natural environment. (6) In the evolutionary course of the Caragena species, there was an evident intraspecific variation within C. davazamcii, from which two morphological types were evolved, i.e., green-leaf type and gray-leaf type. (7) In sense of phylogenesis, C. davazamcii was in the position between C. korshinkii and C. microphylla. The green-leaf type C. davazamcii was similar to C. microphylla, and the gray-leaf type C. davazamcii was similar to C. korshinkii. Thus the evolutionary course could be C. microphylla- green-leaf type C. davazamcii-- gray-leaf type C. davazamcii-- C. korshinkii. (8) Genetic differentiation hadoccurred among Caragana populations in Inner Mongolia Plateau, and this indicated that the adaptation of Caragana populations to their environment was molecularly based. (9) Some certain characteristics of photosynthesis and water metabolism of Caragana species in Inner Mongolia Plateau were in relation to the water conditions of their habitats. (10) The morphological structure of leaf of Caragana species in Inner Mongolia Plateau was in accordance with their physiological and biochemical function. (11) Although the Caragana species in desert possessed many features to adapt to their environment, their adaptation was somewhat limited, and the environmental changes may have gone beyond their adaptability. In summary, the Caragana species in Inner Mongolia Plateau adapted to their environments in ways of group differentiation, species differentiation, geographical cline, morphological types and pop更多还原