论文标题:蒙古冰草(Agropyron mongolicum Keng)的遗传多样性研究
Studies on the Genetic Diversity of Mongolian Wheatgrass(Agropyron mongolicum Keng)
论文作者 解新明
论文导师 云锦凤,论文学位 博士,论文专业 草业科学
论文单位 内蒙古农业大学,点击次数 544,论文页数 92页File Size3812k
2001-05-01论文网 http://www.lw23.com/lunwen_1044212/ 蒙古冰草，遗传多样性，表型数量性状，外稃表面的微形态 特征，等位酶，RAPD
Agropyron mongolicum, Genetic diversity, Phenotypic quantitative characters, Micro-morphological characteristics of lemma surface, Allozyme, RAPDXie Xinming (Grassland Science)
蒙古冰草（Agropyron mongolicum Keng）是一种分布广、抗逆性强的优 良饲用禾草。它不仅具有重要的经济价值，而且具有重要的生态价值和遗 传价值。本文以采自内蒙古锡林郭勒盟西乌旗、白音锡勒种畜场、正蓝旗、 苏尼特左旗、伊克昭盟伊金霍洛旗、呼和浩特市清水河县的6个天然居群 及内蒙沙芦草和蒙古冰草新品系两个栽培品种（系）为材料，采用表型数． 量性状的数量统计方法、外浮电镜扫描、等位酶及RAPD标记的技术手段 对其遗传多样性及其在居群内、居群间、天然居群与栽培品种（系）间的 分布格局进行了深入细致地分析。结果表明：蒙古冰草具有极为丰富的遗 传多样性，且居群内的遗传变异大于居群间，这一结果是由其异交、风媒 的繁育系统所决定；在天然居群与栽培品种（系）间，天然居群的遗传多 样性也明显高于栽培品种（系），这与天然居群异质性的生境特点密切相 关；另外，两个栽培品种（系）间也存在有相当程度的遗传分化，表明了 人工选择在其中所起到的重要作用；UPGMA聚类分析的结果显示，蒙古 冰草的8个居群基本上可被分为与其生境土壤条件和生长条件相适应的3 个类群，即沙地居群，石砾质坡地居群和沙壤质土栽培品种（系）3 类， 充分反映天然环境条件和人为环境条件或者说自然选择和人工选择对蒙古 冰草居群间遗传分化的巨大影响。蒙古冰草如此丰富的遗传多样性为其引 种驯化，选育和培育新品种提供了丰富的材料。其优良的抗旱、抗寒和耐 贫瘠的特性为近缘作物的品种改良，沙地的治理和水上保持以及人工草场 的建植提供了丰富的素材，是一种十分宝贵而又极具开发潜力的种质资 源。
Mongolian wheatgrass (Agropyron mongolicum Keng) is a cross-pollinated, longlived, cool-season and drought-resistant perennial bunchgrass, which has a wide distribution in the Northwest and North China, particularly in Inner Mongolia. Not only does it has an important economic value, but an important ecological and genetic value. Using the materials of six natural populations and two cultivars from the central and east regions in Inner Mongolia, the statistical analysis of the phenotypic quantitative characters of inflorescence, the scanning electron microscope analysis of the micro-morphological characteristics of lemma surface, the allozyme variation and the RA.PD analysis were performed with a view to assessing the genetic diversities and their distribution pattern within and among populations. The results showed that A.mongolicum possessed a higher level genetic diversity within population than that among populations as a result of the cross-pollinated breeding system. Between natural populations and cultivars, the genetic diversity among six natural populations was much higher than that between two cultivars, owing to the environmental heterogeneity of natural populations. In the meantime, there also was a genetic differentiation between two cultivars. It was clear that artificial selection played an important role in the differentiation. UPGMA cluster analysis showed that eight populations could basically be divided into three groups adapted to their own soil conditions. These groups were sand-land populations, gravelly-slope populations and sandy soil cultivars respectively. It is enough to prove that natural and artificial selections have a enormous effect on the differentiation among populations. The abundant genetic diversities of A. mongolicum are the foundation of the utilization of this germplasm resource. The drought-resistant, cold-resistant and barren-tolerant traits can provide some helps for the improvement of kindred crop cultivars, for the water and soil conservation of sand land, and for the construction of artificial grassland. Therefore, the mongolian wheatgrass is a potential and precious germplasm resource.
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