内蒙古草原小叶锦鸡儿遗传分化的研究

采用RAPD技术对内蒙古草原5个具较大地理跨度的小叶锦鸡儿(Caragana microphylla)地理群的遗传多样性和遗传结构特点进行了研究。共检测到466个位点,多态位点463个,多态位点百分率(PPB)为99.36%;特有位点37个,占7.94%。Nei指数和Shannon指数都表明阿巴嘎旗小叶锦鸡儿地理群遗传多样性最高,其它地理群的遗传多样性有向东、向西降低的趋势。AMOVA得到的固定系数φst为0.055 26;基因分化系数Gst为0.067 3,用Shannon指数估算的地理群间变异比率(Hsp-Hpop)/Hsp为0.147 9,说明遗传变异主要存在于各地理群内部。地理群每代迁移数Nm为6.930 5,显示地理群间存在较强的基因流。Mantel检验表明5个小叶锦鸡儿地理群间遗传距离与地理距离有显著相关性。     

内蒙古高原小叶锦鸡儿与中间锦鸡儿遗传多样性的研究

利用ISSR分子标记,选取内蒙古高原自东向西共15个锦鸡儿种群(7个小叶锦鸡儿种群,8个中间锦鸡儿种群)进行遗传多样性分析。结果表明:(1)7个小叶锦鸡儿种群总的多态位点百分数为98.19%,Nei’s基因多样性指数与Shannon信息指数分别为0.289 7、0.444 0;居群间遗传分化系数Gst为0.119 0,表明小叶锦鸡儿种群存在中等程度的遗传分化;居群间基因交流频繁,基因流(Nm)为3.701 0。(2)8个中间锦鸡儿种群多态位点百分数为99.7%,Nei’s基因多样性指数为0.312 8,Shannon信息指数为0.478 4;居群间遗传分化系数(Gst)为0.188 1,表明中间锦鸡儿种群存在较大的遗传分化,基因流(Nm)为2.157 8。(3)中间锦鸡儿遗传多样性及遗传分化均高于小叶锦鸡儿,这是中间锦鸡儿替代小叶锦鸡儿适应不良环境扩展分布的遗传基础。(4)邻接聚类分析结果显示,15个锦鸡儿种群表现为从东到西逐渐聚类,体现了这2个种在分布上的地理渐变性及地理替代性;遗传多样性各指数与气象因子及土壤因子之间的相关性分析表明,平均气温对锦鸡儿种群的遗传分化起着重要的作用。     

昆仑锦鸡儿(豆科)的遗传多样性研究

采用ISSR方法,对昆仑锦鸡儿及其近缘种吐鲁番锦鸡儿的遗传多样性进行检测。结果表明,两个种多态位点百分率分别为79.07%和41.86%,昆仑锦鸡儿遗传多样性水平明显高于吐鲁番锦鸡儿;两个种间的遗传距离为0.394 3;昆仑锦鸡儿居群间的遗传一致度较高(平均0.961 4),遗传分化很低(GST:0.083 6)。     

鄂尔多斯高原不同降雨量梯度中间锦鸡儿(Caragana davazamcii Sancz)种群的遗传结构

为了阐明环境条件对中间锦鸡儿适应状况的影响,在鄂尔多斯高原从东向西按照降雨逐渐减少的梯度选取了5个生境,从遗传多样性的角度出发,应用简单重复间序列（ISSR）方法,对各生境的中间锦鸡儿种群进行了分子生态学研究．结果表明随着生境由东向西的变化,多年平均降雨量的减少,中间锦鸡儿种群遗传多样性有所增加,大部分变异发生在种群内（79．95％）,属异交类型,中间锦鸡儿群体间遗传距离缓慢增加,遗传一致度降低,说明生境条件的变化特别是长期形成的水分条件对中间锦鸡儿的遗传多样性有一定的影响。     

鄂尔多斯高原不同降雨量地区中间锦鸡儿(Caragana davazamcii Sancz)种群的ISSR遗传分析

采用简单重复间序列（ISSR）方法,对鄂尔多斯高原从东向西降雨量逐渐减少选5个地区的中间锦鸡儿种群进行分子生态学研究的结果表明,随着这一地区多年平均降雨量由东向西的逐渐减少,中间锦鸡儿种群遗传多样性有所增加,大部分变异发生在种群内（79.95％）,属异交类型,中间锦鸡儿群体间遗传距离缓慢增加,遗传一致度降低。这种随着水分递减呈现生态梯度变异的现象,说明水分变化特别是长期形成的水分条件对中间锦鸡儿的遗传多样性可能有一定的影响。     

鄂尔多斯高原不同降雨量梯度中间锦鸡儿（Caragana davazamcii Sancz）种群的遗传结构

为了阐明环境条件对中间锦鸡儿适应状况的影响，在鄂尔多斯高原从东向西按照降雨逐渐减少的梯度选取了5个生境，从遗传多样性的角度出发，应用简单重复间序列（ISSR）方法，对各生境的中间锦鸡儿种群进行了分子生态学研究，结果表明随着生境由东向西的变化，多年平均降雨量的减少，中间锦鸡儿种群遗传多样性有所增加，大部分变异发生在种群内（79.95%），属异交类型，中间锦鸡儿群体间遗传距离缓慢增加，遗传一致度降低，说明生境条件的变化特别是长期形成的水分条件对中间锦鸡儿的遗传多样性有一定的影响。     

二色胡枝子遗传多样性ISSR分析

利用ISSR分子标记技术对二色胡枝子的遗传多样性进行分析,16个ISSR引物共扩增出229条带,多态性条带209条,多态性比率为91%,居群的平均多态性位点比率为68.24%,胡枝子总遗传多样性Ht为0.392,Shannon指数为0.576,群体间基因分化系数Gst的变动范围非常大,平均值为0.2434,居群间基因流Nm为1.052。种群内的基因多样性占总群体的75.66%,种群间占24.34%,表明二色胡枝子种群具有丰富的遗传多样性,在育种上具有很大的遗传潜力。根据居群间遗传相似系数聚类,14个居群被聚成3大类群,且居群的遗传多样性参数与其地理、生态因子相关均不显著,遗传多样性无明显的地域性分布格局。     

内蒙古高原甘蒙锦鸡儿的遗传分化研究

对分布于内蒙古和林格尔和阿拉善的甘蒙锦鸡儿(Caragana opulens Kom)种群的叶片形态特性和遗传结构进行了比较研究。结果发现:从叶厚度、面积、长/宽、生物量及SLA来看,阿拉善种群与和林格尔种群之间存在明显变异,阿拉善种群比和林格尔种群保水能力强,对干旱的适应能力好。遗传结构比较研究发现,甘蒙锦鸡儿种群间发生明显的遗传分化(遗传相似度为0.711),表明生物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。     

小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿地理渐变性 Ⅰ.生态学和RAPD证据(英文)

植物种群调查结果证实,小叶锦鸡儿(Caragana microphylla Lam.)、中间锦鸡儿(C.davazamcii Sancz.)和柠条锦鸡儿(C.korshinskii Kom.)在内蒙古高原形成地理替代分布。种群分布、分类、形态、生长发育和遗传结构研究结果表明,小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿地理替代分布是连续的、渐变的,三个种在内蒙古高原自东向西形成一个地理连续渐变群。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地理替代分布状况认为,小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿地理替代分布是适应环境演化的结果。     

毛乌素沙地锦鸡儿（Caragana）种群形态变异

以柠条锦鸡儿（Ｃａｒａｇａｎａｋｏｒｓｈｉｎｓｋｉｉ）人工种群为对照,研究了自然分布在内蒙古毛乌素沙地各类生境（硬梁、覆沙硬梁、覆沙软梁、覆沙滩地和沙丘）的９个锦鸡儿种群的具分种意义的形态特征的变异。荚果长度在一个植株内是比较稳定的性状;但在各个种群内、种群间变异很大,覆盖了小叶锦鸡儿（Ｃ．ｍｉｃｒｏｐｈｙｌｌａ）、中间锦鸡儿（Ｃ．ｉｎｔｅｒｍｅｄｉａ）和柠条锦鸡儿３个种的范围。同一生境不同种群以及不同生境种群的比较,说明,．决定荚果长度的主要是遗传因素,环境因子如水分条件可能只起次要作用。每个自然种群荚果长度的分布出现几个峰值,说明种群遗传组成的异质性。小叶形状和被毛的资料也说明各个种群内和种群间的异质性。看来,该地区锦鸡儿是上述３种锦鸡儿的杂种带（Ｈｙｂｒｉｄｚｏｎｅ）．形态变异资料也说明毛乌素沙地在遗体多样性方面也是生态过渡带。     

Genetic diversity and genetic relationship of Caragana microphylla, Caragana davazamcii and Caragana korshinskii on the Inner Mongolia Plateau, China

C. microphylla, C. davazamcii and C. korshinskii exhibit a geographical replacement series from east to west on the Inner Mongolia Plateau. Currently, there is still a debate about the taxonomic and genetic relationship among these 3 species. We studied the genetic diversity and genetic relationship among these 3 species by analyzing DNA samples of individual plants from within 10 populations with random amplified polymorphic DNA (RAPD) markers. We identified 678 RAPD loci in total, of which all were polymorphic (PPB = 100%). There were 41 unique loci (6.05%). In general, a trend presented that the genetic diversity of these species decreased from east to west. Further, the genetic diversity was significantly negatively correlated with the local annual mean temperature. Analysis of molecular variation (AMOVA) showed that the genetic variation among these 3 species was only 6.08% of the total genetic variation. Between the species, the genetic variation was insignificant (P = 0.9961). The proportion of genetic variation among populations within each species was 11.90% (P < 0.001) of the total genetic variation, and the total genetic variation mainly existed within the populations (82.02%). Estimated with Shannon's index, genetic differentiation within the populations (Hpop/Hsp) was 0.8013, the coefficient of gene differentiation (Gst) was 0.1603, and the gene flow index (Nm) was 2.6192. This, thus, indicates that there is relatively high gene flow among these populations, and that these 3 species are crossbreeding. The genetic diversity level and the population distribution pattern showed geographic continuity to some extent.     

RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii Reshov. in Inner Mongolia steppe

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10 bp oligonucleotide primers, which generated 237 RAPD bands, were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei's diversity index (h), Shannon's diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson's correlation analysis between genetic diversity parameters and ecological parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by precipitation and cumulative temperature). Dendrogram based on Jaccard's genetic distance showed that the individuals from the same population formed a single sub-group. Although most variation (56.85%) was within populations, there was high genetic differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei's unbiased genetic distance (G(ST)) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel's test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation in northern grassland in China may be the main factor responsible for high genetic differentiation among populations, within and among regions.     

大别山山核桃天然群体遗传结构的初步分析

利用RAPD分子标记技术检测了大别山山核桃3个天然居群的遗传多样性和遗传结构。20条10 bp随机引物共检测到238个扩增位点,其中多态性位点162个,多态位点百分率(PPB)为68.1%。居群水平Shannon’s多态性信息指数(I)介于0.2651~0.2801之间;居群水平Ne i’s基因多样性指数(H)介于0.1789~0.1890之间。遗传变异计算显示大别山山核桃居群间基因分化系数(Gst)为0.4063,分子方差分析(AMOVA)表明居群间基因分化水平为0.4177,居群间基因流(Nm)为0.7306,说明大别山山核桃大部分变异存在于居群内,居群间基因交流相对较少。这一结果符合大别山山核桃风媒、异交的繁育系统特点,但其居群间基因分化程度明显高于异交植物的平均水平(Gst=0.1930)。地理隔离、居群内近交及居群间基因流受阻可能是形成目前大别山山核桃天然群体遗传结构的主要因素。     

栲树天然群体遗传结构的RAPD分析

利用RAPD分子标记对 5个栲树 (CastanopsisfargesiiFranch .)天然群体共计 188个个体的遗传多样性和群体遗传结构进行了分析。 4 1个随机寡核苷酸引物共检测到 385个位点 ,其中多态位点 15 7个 ,占 4 0 .78%。物种水平的Shannon多样性指数I=0 .4 5 97,Nei基因多样度h =0 .2 96。遗传变异分析表明 ,栲树群体的遗传变异主要存在于群体内 ,利用Shannon多样性指数估算的分化 (Hsp_Hpop) /Hsp=0 .0 4 76 ,遗传分化系数Gst =0 .0 4 2 9,分子方差分析 (AMOVA)也证实了这一结论 ,群体内的变异组分占了 94 .97% ,群体间变异只占 5 .0 3%。AMOVA分析结果的显著性检验也表明 ,群体间及群体内个体间均呈现出显著分化 (P <0 .0 0 1)。     

濒危植物三棱栎遗传多样性的RAPD分析

用随机扩增多态DNA (RAPD)标记对 5个三棱栎 (Trigonobalanusdoichangensis)居群共 99个个体进行遗传多样性和居群遗传结构分析。 16个引物共检测到 15 7个位点 ,其中多态位点 83个 ,占 5 2 87%。物种水平Shannon多样性指数I =0 2 4 31,Nei基因多样度h =0 15 95 ,种内总遗传变异量Ht=0 16 0 0 ,居群内遗传变异量Hs =0 0 74 9,居群间变异量大于居群内变异量 ,表明三棱栎的遗传变异主要存在于居群之间。与同科植物相比 ,三棱栎遗传多样性较低 ,遗传分化系数Gst =0 5 32 0 ,说明居群间的遗传变异占 5 3 2 0 % ,居群间已出现强烈的遗传分化。当地人的强烈活动造成的生境破碎化和居群隔离 ,以及三棱栎演化过程中的地史变化对其种群发展的影响等 ,可能是造成其居群间强烈的遗传分化和较低遗传多样性的原因。基于本研究结果 ,提出了三棱栎遗传多样性的保护策略。     

RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii reshov. in Inner Mongolia steppe

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10-bp oligonucleotide primers, which generated 237 RAPD bands, were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei’s diversity index (h), Shannon’s diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson’s correlation analysis between genetic diversity parameters and ecological parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by precipitation and cumulative temperature). Dendrogram based on Jaccard’s genetic distance showed that the individuals from the same population formed a single subgroup. Although most variation (56.85%) was within populations, there was high genetic differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei’s unbiased genetic distance (G _ST) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel’s test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation in northem grassland in China may be the main factor responsible for high genetic differentiation among populations, within and among regions. The text was submitted by the authors in English.     

极度濒危植物五针白皮松的保护遗传学研究

用随机扩增多态(RAPD)方法对极度濒危植物五针白皮松(Pinus squamata X.W.Li)的遗传多样性和居群遗传结构进行了研究。14个随机引物共获得93条RAPD谱带,其中6条为多态带,多态位点百分率仅为6．45％,遗传多样性极低。Shannon指数I和Nei指数h在种内也只有0．020和0．030,两个亚居群间(半阴坡亚居群与半阳坡亚居群)遗传分化程度不高,遗传分化系数Gst只有0．110,与大多数松科植物近似,居群每代迁移数为4．032。五针白皮松极低的遗传多样性可能是由于它在演化过程中遭受过严重的灾害,造成严重的瓶颈效应,丧失其大部分遗传变异。在随后的演化过程中由于遗传漂变、自交衰退等小种群现象,导致遗传多样性的进一步丧失。另外,阔叶树种对其生存的挤压和人类的干扰也是导致五针白皮松遗传多样性降低的因素之一。本文最后对该结果的保护生物学意义进行了评价。     

濒危灌木长叶红砂遗传多样性的RAPD分析

应用RAPD分子标记对濒危灌木长叶红砂(Reaumuria trigyna)种群遗传多样性进行了分析.应用18条随机引物对长叶红砂5个种群的95个个体进行扩增,检测到118个位点,其中多态位点105个.结果表明:长叶红砂种群的多态位点比率(P)为88.98%,显示出长叶红砂种群存在较高的遗传多样性.Shannon多样性指数(0.4966)、Nei基因多样性指数(0.3303)和基因分化系数(Gst=0.1425)的分析结果显示,长叶红砂种群遗传变异大多存在于种群内,种群间的遗传分化占14.25%.聚类分析表明,长叶红砂种群遗传距离与地理距离之间无直接相关关系.遗传多样性水平与物种特性和所处不同群落有关,濒危植物并不一定表现为遗传变异水平的降低.     

大别山山核桃种群遗传多样性研究

为了更有效地保护和合理开发大别山山核桃(Carya dabieshanensis)资源,该文利用RAPD分子标记技术,对3个天然大别山山核桃种群的90个单株的遗传多样性、种群内和种群间的遗传变异进行了研究,结果表明:20对10 bp随机引物共检测到238条谱带,其中多态带为162条,占68.1%。遗传多样性分析结果显示: Shannon多样性指数为0.476 1,58.18%的变异分布于群体内,而种群间变异占了41.82%;Nei指数群体总基因多样度为0.314 5,群体内平均基因多样度(H_S)为0.186 5,群体间的基因多样度(H_ST)为0.128 0,群体Nei基因分化系数(G_ST)为0.406 7,说明40.67%的变异存在于种群间,群体内的变异占了总变异的59.33%,与Shannon多样性指数相比基本一致,均表明种群内有较丰富的遗传变异,这为优良品种选育提供广阔前景;种群间的基因流(N_m)为0.730 6,证明种群间遗传交换较小,这与环境适应性和高山阻隔有一定的关系。