Studies on the Steroidal Saponins of Dioscorea tokoro Makino Collected from Zhejiang

Six steroidal saponins were isolated from rhizome of Dioscorea tokoro Makino (collected from Zhejiang). By means of acetylation, acid hydrolysis, IR, MS, and 13C-NMR etc., five of them were identical with yononin (A) (yield 0.0069%), dioscin (C) (0.04%), gracillin (D) (0.03%), protodioscin (E) (0.5%), protogracillin (F) (0.2%), respectively. Because of low yield, saponin B was not identified.     

Temperature dependence of seedling establishment of a perennial, Dioscorea tokoro

The temperature dependence of seed germination and seedling growth was analyzed in Dioscorea tokoro, an East Asian summer-green perennial. Seeds were able to germinate fully only at 11°–20°C. At around 17°–20°C the first leaf petiole of the seedling elongated and quickly set the first leaf blade at a position enabling photosynthesis. At temperatures higher than 20°C petiole elongation was retarded, and seedlings formed a rhizome and established as a perennial. The rhizome size increased with temperature up to 29°C. Thus, during growth immediately after germination, temperature appears to be a key factor in determining whether the plant establishes as a perennial or grows rapidly without rhizome thickening. Received: April 6, 2001 / Accepted: September 14, 2001     

我国盾叶薯蓣居群遗传结构分析

利用随机扩增多态DNA(RAPD)标记,分析研究了中国11个盾叶薯蓣居群82个个体的遗传多样性与遗传结构,15个寡聚核苷酸引物扩增共得到108条带,其中96条为多态带,占88．89％。Shannon多样性指数(I)为0．3093,居群水平的变异从0．1564到0．3098,物种水平的Nei基因多样度(h)为0．2499,居群水平的变化范围为0．1607到0．2137。遗传变异分析表明,物种水平的基因分化系数Gst为0．3415,居群间的基因流Nm为0．9641,居群间遗传交换小。分子方差分析(AMOVA)表明,居群内变异为68．96％,地区间变异为19．45％,居群问变异为11．58％。聚类结果以长江为界,将盾叶薯蓣分为南北两个大类群。研究结果对盾叶薯蓣种质的迁地保护有重要意义。     

马拉硫磷对中华稻蝗种群遗传结构的作用

将中华稻蝗(Oxya chinensis)注射1.5g/L的马拉硫磷,24h后死亡率为56%。用等位酶电泳确定死亡与存活个体在多态性基因座Pgm和Me上的基因型,并比较各基因型的死亡率差异。结果表明：在Pgm基因座上,马拉硫磷对具有不同基因型的中华稻蝗个体存在选择性致死作用,但是在Me基因座上未观察到类似选择性致死作用。在基因座Pgm上,Pgm-ab 基因型个体死亡率最高（80%）,Pgm-bb和Pgm-bc基因型个体死亡率最低（49%）,低于平均死亡率。卡方检验表明,基因型Pgm-bb和Pgm-cc的死亡率之间存在显著差异。在存活个体中,等位基因Pgm-b的频率显著增加。基于Roger’s遗传距离的聚类分析表明,马拉硫磷的急性致死作用会导致中华稻蝗种群遗传组成的变化。马拉硫磷是蝗虫防治中常用的杀虫剂,研究显示,不同基因型在死亡率上的差异也可能存在于田间。 Abstract: Allozyme electrophoresis was employed to compare the difference in mortality among the genotypes at two polymorphic loci of Pgm and Me of grasshopper Oxya chinensis individuals acutely exposed to 1.5g/L malathion which resulted in 56% mortality in 24 hours. The selective lethal effects were observed among the genotypes at Pgm locus but not at Me locus. It is noted that the genotype Pgm-ab experienced the highest mortality (80%), whereas Pgm-bb and Pgm-bc were 49%, lower than the average. The χ2 tests showed significant difference in morality between Pgm-bb and Pgm-cc. After exposure the allele frequency of Pgm-b showed a notable increase among surviving individuals. The cluster analysis based on Roger’s genetic distance indicated that the acute exposure to malathion can cause differentiation in genetic composition at population level in Oxya chinensis. Because malathion is commonly used as the insecticide for grasshopper control, the data obtained in this study suggest that the similar genotype-mortality effects may occur in crop fields.     

云杉矮槲寄生遗传多样性及其群体遗传结构分析

该研究采用CTAB法提取云杉矮槲寄生(Arceuthobium sichuanense)的基因组DNA,利用ITS1片段的序列信息对中国9个不同地理群体的62份云杉矮槲寄生样本的遗传多样性及群体遗传结构进行分析。结果表明:(1)62条ITS1序列共定义16个单倍型(H1~H16),表现出较低的遗传多样性水平(h=0.678 5,π=0.005 9),而群体间的遗传多样性水平则表现出较大差异(h=0~1.000 0,π=0~0.009 4);AMOVA分析显示云杉矮槲寄生群体内的遗传变异占到51.37%,群体间为48.63%。(2)Network单倍型网络分析表明,单倍型H1和H12较为古老,且所有群体对2种单倍型无共享现象;单倍型H1是广布单倍型,存在于青海和甘肃的6个群体中,单倍型H12仅在四川的2个群体中有分布。(3)基于最大似然法(ML)构建的群体聚类和中介邻接法构建的单倍型网络图均显示,四川的3个群体为独立类群,区别于青海、甘肃群体,且甘肃和青海的群体之间没有明显分化。该研究首次报道了云杉矮槲寄生遗传多样性和遗传结构,为进一步研究其进化及后续的病害防控提供了一定的参考。     

用扩增片段的长度多态性分子标记探讨盾叶薯蓣的遗传多样性

用扩增片段的长度多态性(amplified fragment length polymorphism,AFLP)标记分析研究了中国5个盾叶薯蓣居群30个个体的遗传多样性。筛选出9对AFLP引物,从中检测到14698条清晰可见的条带,其中多态性带12628条,多态性比率85.92%。Shannon信息指数(I)为0.3656±0.1721,物种水平的Nei基因多样性(H)为0.2322±0.2200。遗传变异分析表明,物种水平的遗传分化系数Gst为0.4827,说明其群体间存在一定的遗传分化,居群间的基因流Nm为0.5358,居群间遗传交换较小。聚类分析结果显示5个居群盾叶薯蓣有较为丰富的遗传变异,且与地理分布有相关性。     

北沙柳群体遗传多样性和遗传结构分析

以内蒙古北沙柳(Salix psammophila)国家种质资源库内9个群体(P1~P9)288个无性系为实验材料,利用TP-M13-SSR技术,选取22对具有多态性EST-SSR北沙柳引物,采用毛细管电泳对PCR产物进行检测,分析北沙柳遗传多样性、分化程度和群体遗传结构,为北沙柳种质资源库遗传管理、无性系鉴定、品种选育、遗传改良和构建指纹图谱提供理论依据。结果显示:(1)22对EST-SSR引物共检测到222个等位基因,各位点平均等位基因数(A)为10,四倍体基因型丰富度(G)和特异基因型(G1)总和分别为1 460和802个,平均特异基因型比率(P1)和种质鉴别率(P2)分别为45.86%和13.21%。(2)9个群体平均等位基因数(A)为7.475,基因型丰富度(G)为15.586,观察杂合度(Ho)和期望杂合度(He)分别为0.577和0.638。以期望杂合度He为标准,北沙柳群体遗传多样性水平最低的是P1和P9。(3)北沙柳群体遗传分化系数仅为0.02,AMOVA分子变异分析显示,北沙柳群体大部分遗传变异来自群体内(97%),群体间变异仅为3%。(4)三维主成分、聚类和Structure群体遗传结构分析显示,9个群体被划分为2个组,Mantel检验表明北沙柳遗传距离与地理距离极显著相关(r=0.684 P0.001)。研究表明,北沙柳种质资源具有丰富的遗传多样性,这是其具有耐旱、耐寒、耐高温、耐沙埋和抗风蚀等适应性较强的分子基础;北沙柳的遗传变异集中在群体内;分布区群体呈现由中心向边缘群体扩张分化的趋势。     

黄独遗传多样性研究

采用ISSR标记技术研究了我国14个黄独样品的遗传多样性.从55条简单重复序列引物中筛选出9条多态性引物,共扩增出70条带,其中67条多态性带,多态性比率为95.71%,平均每条引物扩增出7.8条带.黄独原变种内Nei s基因多样性(h)为0.294 9,有效等位基因数(Ne)为1.491 1,Shannon多样性指数(I)为0.444 8.种水平h为0.326 3,Ne为1.552 9,I为0.488 3.基因分化系数(Gst)为0.782 1,基因流(Nm)为0.139 3.聚类分析表明来自海南省和台湾省的样品与我国内陆的样品较早分离.据此可将来自我国内陆的样品分为5组.ISSR聚类分析基本上支持依据形态特征对黄独变种的划分.同时实验结果也表明,云南可能是黄独在我国的分化中心.     

303份甘薯地方种SSR遗传多样性与群体结构分析

利用SSR分子标记,对我国303份甘薯地方种进行了遗传多样性和群体结构分析。进一步明确了甘薯地方种间的遗传多样性和亲缘关系,为优异资源挖掘和品种改良提供了参考。利用SSR建立研究材料的0~1数据库,通过NTSYS-pc2.10软件计算Nei72遗传距离矩阵,将遗传距离矩阵导入MEGA 6.06,计算平均遗传距离和聚类分析;并利用STRUCTURE2.3.4对303份地方种进行群体结构分析。结果表明:30对SSR引物共检测出203条多态性位点,每对引物检测到1~14条多态性条带,平均每对引物获得6.77条。303份材料的平均遗传距离为0.564,聚类分析在遗传距离为0.477处可以把303份材料分成11个类群,其中第Ⅺ类群在遗传距离为0.452处可分为3个亚群。群体结构分析将303份材料划分成了5个稳定的群体,群体结构划分与聚类有相似的结果,其中70份材料Q值小于0.6,属于混合亚群。     

濒危植物观光木遗传多样性及遗传结构分析

采用筛选的8条ISSR引物对濒危植物观光木13个野生种群的遗传多样性及遗传结构进行分析,结果显示:物种和种群水平上多态性位点百分率分别为79.67%和46.84%,Shannon表型多样性指数分别为0.3880和0.2192,与木兰科其他近缘植物相比,遗传多样性水平较高;分子方差分析表明,观光木野生种群间遗传分化系数为0.3752,种群间存在显著的遗传距离;STRUCTURE分析和UPGMA聚类表明,参试的13个野生种群可分为3大类群;相关性分析表明,种群间遗传距离与其地理距离呈显著正相关。南昆山、笔架山、弄相山种群的遗传多样性最丰富,建议优先加以保护。     

Genetic Structure in a Heterocyanic Population of Trillium sessile (Liliaceae)

Abstract Species of Trillium in the subgenus Phyllantherum are either polymorphic for flower color, or monomorphic for flower color and related to a polymorphic species. This leads to the suggestion that polymorphic species may be the progenitors for monomorphic ones. For this to be true, it must be demonstrated that genetic divergence among flower morphs can occur within polymorphic populations. Genetic structure was assessed in a population of T. sessile that contains a polymorphism for flower color. A survey of 11 enzyme systems using starch gel electrophoresis revealed three polymorphic loci: 6PGD-1, AAT-1 and AAT-2. Analysis of large and small scale spatial structure, stage classes, and flower color classes revealed significant genetic divergence in all instances. Spatial structure in the population is likely a result of genetic neighborhoods which can maintain populational variation via random genetic drift. Genetic divergence of the yellow flower color morph was probably initiated through genetic drift since the morph occurs in low frequencies. The results imply that the initial genetic divergence of species in the subgenus can arise within polymorphic populations.     

Development and characterization of microsatellite markers in a clonal plant,Dioscorea japonica Thunb.

We developed 10 microsatellite loci from genomic DNA of a dioecious clonal plant, Dioscorea japonica. Out of 384 clones, 148 contained microsatellite repeats. Polymerase chain reaction primer pairs were designed for 95 of these clones from their sequence data, of which, 10 pairs produced successful amplification. Thirty‐eight individuals were genotyped for allelic diversity. We detected three to nine alleles per locus, and the expected heterozygosity ranged from 0.461 to 0.851.     

湖北3种药用淫羊藿植物等位酶多样性与居群遗传结构

采用超薄平板微型聚丙烯酰胺等电聚焦电泳方法对湖北3种淫羊藿属（Epimedium L．）药用植物：柔毛淫羊藿（E．pubescens Maxim．）、箭叶淫羊藿（Esagittatum（Sieb．＆Zucc．）Maxim．）和巫山淫羊藿（Ewushanense T.S．Ying）的11个自然居群进行了等位酶种内遗传多样性和居群遗传结构以及种间遗传关系的研究。6个酶系统在3种淫羊藿植物中检测到13个酶位点共45个等位基因,分析结果表明：1）3种淫羊藿均具有较高的遗传多样性水平（A=2．6-3．2,P=69．2％-84．6％,Ho=0．274-0．377,HE=0．282-0．369）,远高于多年生草本植物和依靠动物传粉植物的平均水平;2）所有居群都显著偏离Hardy—Weinberg平衡,大多数多态位点固定指数（F）明显偏离于0且正负值各半,暗示该属植物可能具有复杂的繁育系统;3）种内和种间的遗传分化度均较低,分别为GST=0．0246-0．0409和0．0495-0．1213,表明种内居群间存在较高的基因流和种间较近的遗传关系;4）聚类分析表明柔毛淫羊藿与箭叶淫羊藿的亲缘关系更近,这与形态学特征、花瓣演化趋势及系统发育分析等方面的研究的结果相吻合。讨论分析认为3种淫羊藿植物的遗传变异特性是由淫羊藿属植物异交与克隆繁殖的混合繁育系统、多年生的生活特性、古老的进化历史和种子的蚁播特性等多因素共同决定的。     

Evaluation of Genetic Diversity and Population Structure Analysis among Germplasm of Agaricus bisporus by SSR Markers

Agaricus bisporus is a popular edible mushroom that is cultivated worldwide. Due to its secondary homothallic nature, cultivated A. bisporus strains have low genetic diversity, and breeding novel strains is challenging. The aim of this study was to investigate the genetic diversity and population structure of globally collected A. bisporus strains using simple sequence repeat (SSR) markers. Agaricus bisporus strains were divided based on genetic distance-based groups and model-based subpopulations. The major allele frequency (MAF), number of genotypes (NG), number of alleles (NA), observed heterozygosity (HO), expected heterozygosity (HE), and polymorphic information content (PIC) were calculated, and genetic distance, population structure, genetic differentiation, and Hardy–Weinberg equilibrium (HWE) were assessed. Strains were divided into two groups by distance-based analysis and into three subpopulations by model-based analysis. Strains in subpopulations POP A and POP B were included in Group I, and strains in subpopulation POP C were included in Group II. Genetic differentiation between strains was 99%. Marker AB-gSSR-1057 in Group II and subpopulation POP C was confirmed to be in HWE. These results will enhance A. bisporus breeding programs and support the protection of genetic resources.     

基于SRAP标记的山药种质资源遗传多样性分析

目的:研究我国山药种质资源遗传多样性,为合理利用资源和开展选育种工作提供理论依据。方法:以国内94份山药种质资源为材料,采用SRAP标记并通过NTSYS2.10软件进行SHAN聚类分析、PROJECTION主成分分析;利用POPGENE软件估算遗传多样性参数。结果:从49对SRAP引物中筛选出30对能产生稳定清晰可辨的扩增产物的引物,共扩增出754条DNA带,其中多态性条带616条,占总条带的81.7%。聚类结果表明:当遗传相似系数(GS)为0.822时,可将94份资源分为5类:第Ⅰ类20份、第Ⅱ类43份、第Ⅲ类7份、第Ⅳ类3份、第Ⅴ类21份。第Ⅰ、Ⅱ、Ⅲ、Ⅴ类分别为薯蓣、褐苞薯蓣、山薯和参薯。主成分分析结果显示:第一与第二主成分可解释88.34%(82.10%和6.24%)的遗传总变异。遗传多样性参数分析表明:比较5个遗传多样性参数值,5个群体的遗传多样性水平表现为Ⅰ>Ⅴ>Ⅲ>Ⅱ>Ⅳ,第Ⅰ类(薯蓣)遗传多样性水平高;山药遗传群体间遗传分化系数为51.88%,大部分差异存在于群体之间,群体间遗传分化高。结论:山药种质资源丰富且群体遗传分化高,有利于山药新品种的选育。SRAP标记可有效应用于山药种质资源的鉴别和遗传多样性分析。通过DNA指纹鉴定技术鉴别山药品种具有重要性与紧迫性。     

111份大薯种质资源遗传多样性的AFLP分析

采用AFLP分子标记方法对收集于6省不同地区的111份大薯种质资源进行遗传多样性分析。筛选到的8个AFLP引物组合扩增到1291个位点,其中1286个是多态性位点。利用多态性信息含量(PIC)、标记指数(MI)和解析强度(RP)分析不同引物组合的标记效率,获得引物的PIC平均值为0.22,MI平均值为35.67,RP平均值为50.50,表明引物扩增位点的高多态性和对大薯种质资源具有强辨别能力,其中引物E-AAC/CAG-M(PIC 0.24、MI 38.56、RP 56.35)具有较高的标记效率。111份大薯种质的遗传相似系数(GS)在0.30~0.82之间,平均为0.58,表明大薯种质资源的遗传相似性较低。采用UPGMA对大薯种质进行聚类分析,遗传相似系数在0.54时,111份材料被划分为4个类群和3个单独的分支,不同地区来源的大薯材料在聚类图中没有明显界限。     

内蒙古西伯利亚杏群体遗传多样性和遗传结构分析

利用27对SSR分子标记对内蒙古地区13个西伯利亚杏群体的遗传多样性和遗传结构进行分析,评价其遗传多样性水平和分化程度,为内蒙古西伯利亚杏资源的合理保护与利用提供理论依据。结果显示:(1)27对SSR引物共检测到512个等位基因(Na),各位点平均等位基因数(Na)和多态性信息含量(PIC)分别为19和0.84;物种水平上Shannons信息指数(I)和期望杂合度(He)分别为2.25和0.73。(2)群体水平上的等位基因(Na)、有效等位基因(Ne)、Shannons信息指数(I)、期望杂合度(He)和观察杂合度(Ho)分别为6.95、4.48、1.60、0.76和0.56;其中科左后旗群体遗传多样性最丰富,克什克腾旗群体遗传多样性最低。(3)基于F统计量分析的遗传分化系数(Fst)为0.12,基因流(Nm)为1.86;分子方差分析显示内蒙古西伯利亚杏群体大部分遗传变异来自群体内(92%),群体间的遗传变异仅占8%。(4)内蒙古西伯利亚杏群体遗传距离为0.04~0.67,遗传相似度为0.33~0.83;遗传相似度的聚类分析、遗传距离的主坐标分析和遗传结构分析(Structure)均将供试13个群体划分为4组。Mantel检测显示,内蒙古西伯利亚杏群体遗传距离与地理距离呈显著相关关系(r=0.453,P0.01)。研究表明,内蒙古西伯利亚杏资源具有丰富的遗传多样性,这一特性与其群体的大小、悠久的演化历史以及自身生物学特性相关;内蒙古西伯利亚杏群体间存在中等程度的遗传分化,这可能源于自然地理隔离以及近期人类活动引起的生境片段化。     

茄子种质遗传多样性及群体结构的SRAP分析

采用SRAP标记法对183份茄子(Solanum melongena)种质资源的遗传关系和群体结构进行分析。结果表明, 33对多态性SRAP引物组合共扩增出215条清晰稳定的多态性条带, 平均每对引物组合产生7条多态性条带。183份茄子种质的遗传相似系数介于0.276-0.813之间, 平均值为0.623, 表明茄子种质资源间遗传背景存在一定的差异。在遗传距离为0.345 6处可将183份茄子种质分为4组。通过群体结构分析可将种质划分为4个群体, 不同群体间的界限十分明显, 且群体间的基因渗透较高。