尖叶拟船叶藓与异猫尾藓的同工酶比较

采用聚丙烯酰胺凝胶电泳方法,对尖叶拟船叶藓和异猫尾藓的过氧化物酶（POD）、酯酶（EST）和超氧化物歧化酶（SOD）等3种同工酶进行了分析研究,结果表明：3种同工酶不仅清楚地显示出尖叶拟船叶藓和异猫尾藓同属于船叶藓科所具有的共同特征酶带,而且酶谱还显示出了种间及各居群间存在的差异.2个种在3种同工酶上表现出较高的相似性,说明拟船叶藓属和猫尾藓属之间有较近的亲缘关系.在物种水平上,异猫尾藓的遗传多样性高于尖叶拟船叶藓,在种内居群间,尖叶拟船叶藓的遗传多样性较高,且受环境因素的影响较大.     

树干附生尖叶拟船叶藓的分布与环境关系

通过野外调查和室内测量,并利用统计分析方法对贵州梵净山的尖叶拟船叶藓的分布进行了研究,结果表明:在梵净山的分布范围内,海拔和坡向对尖叶拟船叶藓分布的影响不显著;尖叶拟船叶藓在5种附生树上、中、下3个部位的分布与对应部位的树皮含水量呈正相关(r值分别为0.75,0.74,0.82,0.44,0.15);尖叶拟船叶藓在不同倾斜程度附生树干的近地面和远地面之间分布的显著差异与近地面和远地面树皮的含水量有正相关关系,树皮水分是影响尖叶拟船叶藓分布的主要因素.     

贵州梵净山尖叶拟船叶藓Dolichomitriopsis diversiformis(Mitt.)Nog.群落生态环境特征初探

通过野外调查观测和室内分析 ,对东亚特有濒危植物尖叶拟船叶藓Dolichomitriopsisdiversiformis(Mitt.)Nog .群落在梵净山的生态环境进行了初步研究 ,结果表明该植物分布在 170 0m— 190 0m范围的常绿阔叶林内 ,主要伴生植物为白发藓Leucobryum glaucum、羽藓Thuidiumsp .、刀叶树平藓Homaliodendronscalpellifolium和膜蕨Hymenophyllumsp .等 ,喜阴湿及西北向散射光 ,其附生树种没有明显的专一性。与所处的森林群落土壤环境相比 ,尖叶拟船叶藓群落附生基质中K、Ca、Mg、Fe、Cu的含量较高 ,Mn、Zn、P的含量低。与伴生植物相比 ,尖叶拟船叶藓植物体内Fe含量高 ,K、Ca、Mg、Cu含量低 ,而Mn、Zn和P含量处于中等水平     

不同种群狭叶小羽藓(Haplocladium angustifolium)重金属含量及遗传多样性

以上海市狭叶小羽藓居群为实验材料,测定不同居群植物体中的重金属元素含量,利用随机扩增多态DNA标记技术（random amplified polymorphic DNA,RAPD）对不同浓度重金属污染下的小羽藓居群的遗传多样性和遗传分化进行了初步分析．结果表明：104个检测位点中发现94个多态性位点,多态位点百分率为91．35％,总的居群的Nei基因多样性指数（H）为0．2682,Shannon指数（I）为0．4108,小羽藓种群表现出较高的遗传多样性．总的遗传居群间遗传分化系数（Gst）为0．5591,居群内遗传分化系数（协）为0．1182,居群间的变异程度远远大于居群内的变异程度．将各个样点居群的Shannon信息指数同重金属含量做相关性分析得出,Shannon信息指数的增加同Cr含量呈明显正相关,表明Cr胁迫对小羽藓种群的遗传分化有较大程度的影响．     

神农架大九湖湿地泥炭藓遗传多样性RAPD研究

泥炭藓是重要的沼泽湿生藓类,其生长情况对环境气候变迁具有直接的指示意义.通过RAPD分子标记对湖北神农架47份泥炭藓样品的遗传多样性进行了研究:(1)对20条随机引物进行筛选,共选出6条重复性好,条带清晰的引物,对47份样品共扩增出40个条带,多态性比率为95%;(2)以遗传相似性系数0.61为界限,可将47份样品划分为4大类群;(3)对泥炭藓扩增条带的聚类分析显示,大九湖湿地泥炭藓遗传多样性与采样点地域之间没有明显的相关性.对上述结果综合分析表明:大九湖湿地泥炭藓遗传多样性水平较低,一定程度上反映出近些年来旅游开发、排水工程改造等人类活动对大九湖湿地自然环境的影响.     

狭边大叶藓(Rhodobryum ontariense)遗传多样性的ISSR分析

狭边大叶藓[Rhodobryum ontariense(Kindb.)Paris]为真藓科大叶藓属植物,具有治疗心血管疾病的功效。本研究选用ISSR分子标记对分布于河北、河南、四川和陕西四省的9个狭边大叶藓自然居群的遗传多样性进行研究,目的在于揭示狭边大叶藓居群的遗传结构和遗传多样性水平,为其保护和合理开发利用提供科学依据。用8个ISSR引物对9个居群共58个样品进行扩增,共获得47条清晰的扩增位点。POPGENE分析表明,狭边大叶藓居群遗传多样性水平较低(多态性位点比率为37.75%,Nei’s基因多样性为0.153 0,Shannon’信息指数为0.222 8,遗传分化指数Gst为0.299 7,居群间的基因流为1.168 2)。AMOVA分析表明,大多数遗传变异(84.07%)存在于居群内,15.93%的遗传变异存在于居群间(Φst=0.159 3)。UPGMA聚类分析表明,狭边大叶藓居群遗传距离和地理距离没有相关性(r=0.404 95,p=0.979 1)。     

灰尖巴蜗牛的遗传多样性研究

以线粒体COI基因为分子遗传标记,通过分子生物学方法分析曲靖地区灰尖巴蜗牛5个种群的COI基因DNA序列,从分子水平探讨该物种群体和种群遗传多样性.研究结果表明,该物种群体COI基因序列有变异位点47个,包括简约信息位点43个(转换与颠换)和单突变位点4个;核苷酸A、C、T、G所占比例分别为32.50%、29.43%、27.54%和10.53%,并确定了14种单倍型.在5个种群中,单倍型多样性(H)最高的是P1和P3,最低的是P4;核苷酸多样性(Pi)最高的是P2,最低的是P4;核苷酸成对差异比较明显的是P1.上述结果表明曲靖灰尖巴蜗牛整个群体的COI遗传多样性偏低,这为针对该物种综合防治措施的制定提供了重要参考依据.     

拟穴青蟹群体遗传多样性的ISSR分析

采用ISSR技术对拟穴青蟹（Scylla paramamosain）3个地理群体：福建群体（FJ）、广西防城港群体（FC）和北海群体（BH）的遗传多样性进行检测。用10对ISSR引物对90个个体进行PCR扩增,用POPGENE32计算遗传参数,并用ARLEQUIN软件进行AMOVA分子变异分析。结果共检测到63个位点,多态位点数为56。福建、防城港和北海群体Nei＇s基因多样性指数（He）分别为0.2670、0.1819和0.2257,Shannon＇s信息指数（I）分别为0.3945、0.2708和0.3371,遗传多样性水平从高到低依次为FJ〉FC〉BH。He和I在群体水平上分别为0.2248和0.3341,在物种水平上分别为0.3186和0.4337。拟穴青触32.34%的变异发生在群体间,67.66%的变异发生在群体内,3个群体间的遗传分化系数为0.1542,产生了一定的遗传分化。     

环境因子对岩生植物金发草遗传多样性的影响

采用ISSR标记技术对四川、云南、重庆、广西等地不同环境条件下22个金发草种群的遗传变异进行分析。从100条引物中筛选出14条引物进行PCR扩增,共扩增出239条清晰的条带,其中227条条带具有多态性,多态位点百分率(PPB)达94.98%,金发草的观测等位基因数(Na)、有效等位基因数(Ne)、Ne i s的基因多样性(H)和Shannnon s信息指数(I)分别为1.9498±0.2188、1.4298±0.3204,0.2656±0.1592及0.4136±0.2088,揭示了金发草具有丰富的遗传多样性。根据Ne i s遗传距离对22个种群进行UPGMA聚类,表明金发草种群的遗传距离与其水平地理距离和垂直地理距离有关。M antel检验表明金发草种群间的遗传距离与水平地理距离和垂直地理距离均呈显著正相关(P<0.01),随着海拔升高,金发草的遗传多样性降低,推测可能是高海拔地区气温低、降水量大在一定程度上影响了金发草种群间的基因交流。生境类型、海拔高度、土壤类型、土壤pH、年均温度、年均降水量、年均日照时数等环境因子对金发草的遗传分化在一定程度上产生了影响,相关性分析表明,其影响均不显著,说明金发草种群对环境依赖性小,能分布在各种生境中,使其具有较高的遗传多样性水平。     

刺五加遗传多样性的RAPD分析

选取我国东北哈尔滨地区刺五加３个居群共４９个单株的新鲜叶片，提取化基因组ＤＮＡ〈使用ＯＰＡ和ＯＰＢ系列８个随机引物进行ＰＣＲ反应，对ＤＮＡ样本做ＲＡＰＤ分析，３个居群多态ＲＡＰＤ位点的百分数分别为９３．５％，９１．３％和９７．６％；３个居的平均遗传距离分别为０．２４１，０．３６３和０．３８８；３个居群两两单株之间的平均遗传距离分别为０．３４５，０．３９０和０．４１２，结果表明刺五加种内居群内和居     

尖叶拟船叶藓愈伤组织诱导实验

以尖叶拟船叶藓(Dolichomitriopsis diversiformis (Mitt.) Nog.)原丝体为外植体,研究2种植物激素(2,4-D和6-BA)对其愈伤组织诱导的作用,并在显微镜下观察原丝体细胞在愈伤组织诱导过程中的变化特征.实验结果表明：植物激素对其愈伤组织的诱导是必需的,2,4-D质量浓度为1.0～1.5 mg/L时对愈伤组织诱导无影响,6-BA质量浓度为1.0～1.5 mg/L时能诱导出愈伤组织.     

Morphological variability and genetic diversity in five species of Skeletonema （Bacillariophyta）

Twelve strains of Skeletonema from Chinese coastal waters and another strain from the West Sea of Korea were examined using light microscopy （LM）, scanning and transmission electron microscopy （SEM, TEM）, and small subunit （SSU） rDNA sequence analysis. We identified four species of Skeletonema： S. marinoi Sarno et Zingone, S. subsalsum （A.Cleve） Bethge, S. dohrnii Sarno et Kooistra, S. trop- icum Cleve, as well as a Skeletonerna-like species. These are the first records of S. rnarinoi, S. dohrnii and S. subsalsurn in China. The Skeletonema-like species, MMDLS067, was isolated from the estuary of the Changjiang River. The morphologic and phylogenetic characteristics of this species are not correspond to those of any previously published Skeletonerna species. The intercalary fultoportula pro- cesses （IFPPs） has long open tubes, and the intercalary rimoportula process （IRP） is short and located inside the rim of the IFPPs. Phylogenetic analysis revealed that MMDL5630 clustered with S. tropicurn in the NJ and MP trees, but its IRPs differed from those of previously described specimens of S. tropicum. The IRP is partially open, with an elongated opening at the base of the tube, and is longer than the IFPPs. Some specimens of S. marinoi and S. dohrnii also have longer tubular IRPs than the IFPPs. Compared to pre- viously described specimens of S. rnar＆oi and S. dohrnii, these two specimens we identified have shorter IRPs. Our results reflect the ambiguity and diversity of Skeletonema taxonomy. They are also significant for the future identification and management of red tides caused by Skeletonerna in the seas around China.     

榛子种质资源遗传多样性的RAPD分析

利用RAPD分子标记技术,对来自欧洲、美国和我国北方的共48份榛子品种或品系（包括4个种及种间杂种）的遗传多样性进行了分析．从150条随机引物中筛选出24条引物,共扩增出142条清晰可重复的带,其中多态性带130条,比例为91．5％．聚类分析将48份榛子种质分为5组：欧榛、平榛各自列为1组;杂交榛分成2个组;另外一组包括滇榛和藏榛2份种质．研究结果对榛子的种间亲缘关系进行了验证,且为同种不同品种的亲缘关系提供了更为详细的信息．     

The genetic diversity of cen-tral and peripheral popula-tions of ratlike hamster(Cricetulus triton)

The impact of habitat fragmentation and isolation on the genetic diversity of populations has attracted much attention in studies of meta-population and conservation biology. In this work, using the randomly amplified polymorphic DNA (RAPD) technique, we studied the genetic diversity of central, peripheral and peninsular populations of ratlike hamster, which were collected in five locations of the North China Plain and its surrounding areas, in 1999. The study revealed that, ⅰ) the genetic diversity of central population of Raoyang County＞the sub-central populations of Gu'an County and Taikang County＞the peripheral population of Shunyi District＞the peninsular population of Mentougou District; ⅱ) the genetic diversities of the five populations were positively correlated to the nearest distances to the peripheral line of population distribution; ⅲ) there were significant differences of gene frequencies of some RAPD fragments among the five populations. More RAPD fragments disappeared in peripheral populations than in central or sub-central populations. The frequencies of two RAPD fragments were correlated to the latitude. This study clearly indicated that the variation of the genetic diversities of the five populations was caused by edge effect and frag- mentation through the enhanced inbreeding and genetic drift, and thus supported the view that habitat fragmentation and related edge effect reduce the population genetic diversity.     

环境因子对大石鸡种群遗传多样性的影响

分别以mtDNA的非编码基因D-loop和编码基因Cytb为分子标记,研究了大石鸡分布区内12个种群遗传多样性与环境因子之间的相关性.173个样本的D-loop部分序列(1127 bp)中共发现了34个多态位点,定义了44种单倍型;230个样本的Cytb部分序列(807 bp)中共发现了13个多态位点,定义了14种单倍型.基于D-loop和Cytb的单倍型多样性和核苷酸多样性与样本量之间均无显著相关性.所有的种群遗传多样性与环境因子相关性检验中,基于D-loop的核苷酸多样性与降水量的负相关、基于Cytb的单倍型多样性与纬度和相对湿度变异系数的负相关以及基于Cytb的核苷酸多样性与相对湿度变异系数的负相关达到了显著水平,说明纬度、降水和相对湿度变异系数是影响大石鸡遗传多样性的主导因子,低纬度、干旱以及气候稳定的环境下,大石鸡的遗传多样性更高.     

100份中国冬瓜种质资源农艺性状与遗传多样性研究

冬瓜（Benincasa hispida Cogn）,属于葫芦科(Cucurbitaceae)冬瓜属一年生植物,具有明显药用和保健价值。国内对冬瓜种质资源的系统研究较少,分类标准模糊不一。对我国100份冬瓜种质资源的熟性与果实特征进行详细的研究与分析,并利用隶属函数进行冬瓜的熟性、果形的分类。首次利用模糊数学方法提出冬瓜的熟性、大小与果形分类的量化指标。采用RAPD分子标记技术分析中国冬瓜种质资源。挑选11条RAPD引物对这些资源进行遗传多样性分析。共扩出74 带,其中有多态性位点30个。采用UPGMA聚类分析它们的亲缘关系,这些冬瓜品种资源的相似系数在0.703-0.986之间。     

Evaluation of genetic diversity and relationships within and between two breeds of duck based on microsatellite markers

The genetic diversity of two natural populations (M, N) of Beijing duck (Anas platyrhynchos) and 11 artificially selected lines of Beijing duck (A, B, E-L, O) from China Gold Star Duck Production Ltd., along with two Cherry Valley duck lines (C and D) from the British Cherry Valley Livestock Division, was evaluated using 18 microsatellite markers covering 16 linkage groups. A phylogenetic tree of the 15 populations of duck, formed of four main branches, was constructed from Nei’s D_A genetic distance. The mean genetic differentiation index (F_ST) in all loci, Nei’s standard genetic distance (Ds), and the genetic distance D_A between the Beijing duck and the Cherry Valley duck were 0.075, 0.143 and 0.142, respectively. These results demonstrated a high degree of genetic similarity between the two breeds and supported the hypothesis that the Cherry Valley duck was derived from the Beijing duck. The F_ST matrix of seven clusters of Beijing duck suggested that the efficiency of selection was not significant to some extent and should be supplemented by marker-assisted selection.