沙田柚系列遗传关系的RAPD标记研究

采用 RAPD标记技术分析了沙田柚系列 1 2个样品的遗传关系。利用经筛选具多态性的 1 4个 1 0碱基随机引物对 1 2个样品进行 DNA随机扩增 ,获得清晰可重复的位点 99个 ,其中多态性位点 5 8个 ,占 5 8.89% ;在部分样品中检出了特异性 RAPD标记 1 9个 ,占 1 9.1 9% ;通过样品间遗传相似性系数比较与 UPGMA聚类分析 ,并根据历史事实可知 ,广西沙田柚、梅州金柚为沙田柚的无性繁殖系 ,软枝系沙田柚、沙田柚早熟单株为沙田柚的芽变后代 ,梅花早柚、菊花心沙田柚、冬瓜圈沙田柚、段氏柚、垫江沙田柚、古老钱沙田柚为沙田柚的实生变异品系。     

Asexual genetic variability inAgavaceae determined with inverse sequence-tagged repeats and amplification fragment length polymorphism analysis

Agaves are succulent monocot plants rich in fibers, sugars and other important compounds. They are also valued as ornamental plants and for their ability to grow in poor soils. In the present study, inverse sequence-tagged repeats (ISTR) and amplified fragment length polymorphism (AFLP) analysis were used to study genetic diversity in differentAgavaceae plant samples. Comparison of the banding patterns between the mother plant and rhizome-derived daughter plants showed that genetic variability is generated during asexual reproduction in these species. Phylogenetic relationships amongAgave species were obtained using unweighted pair-group method, arithmetic average (UPGMA) analysis. Genetic diversity through asexual propagation allows for genetic selection and improvement within these asexually propagated plants.     

RAPD分析花椰花不同品种的遗传变异

利用随机扩增多态性DNA（RAPD）方法,对13个花椰花品种的基因组DNA进行多态性分析。选用20个10bp随机引物,共扩增出175条DNA片段,其中多态性片段118例,占67．4％,结果表明,花椰花品种间具有丰富的遗传多样性。依据扩增结果进行遗传相似系数分析,构建聚类分析树状图。初步探讨了各品种间的遗传变异关系及RAPD技术在花椰花种质资源分类鉴定和育种工作中的应用前景。     

Genomic analysis unveils reduced genetic variability but increased proportion of heterozygotic genotypes of the intensively managed mezcal agave,Agave angustifolia

Premise

The central Oaxaca Basin has a century-long history of agave cultivation and is hypothesized to be the region of origin of other cultivated crops. Widely cultivated for mezcal production, the perennial crop known as “espadín” is putatively derived from wild Agave angustifolia. Nevertheless, little is known about its genetic relationship to the wild A. angustifolia or how the decades-long clonal propagation has affected its genetics.

Methods

Using restriction-site-associated DNA sequencing and over 8000 single-nucleotide polymorphisms, we studied aspects of the population genomics of wild and cultivated A. angustifolia in Puebla and Oaxaca, Mexico. We assessed patterns of genetic diversity, inbreeding, distribution of genetic variation, and differentiation among and within wild populations and plantations.

Results

Genetic differentiation between wild and cultivated plants was strong, and both gene pools harbored multiple unique alleles. Nevertheless, we found several cultivated individuals with high genetic affinity with wild samples. Higher heterozygosity was observed in the cultivated individuals, while in total, they harbored considerably fewer alleles and presented higher linkage disequilibrium compared to the wild plants. Independently of geographic distance among sampled plantations, the genetic relatedness of the cultivated plants was high, suggesting a common origin and prevalent role of clonal propagation.

Conclusions

The considerable heterozygosity found in espadín is contained within a network of highly related individuals, displaying high linkage disequilibrium generated by decades of clonal propagation and possibly by the accumulation of somatic mutations. Wild A. angustifolia, on the other hand, represents a significant genetic diversity reservoir that should be carefully studied and conserved.

     

忍冬属植物的遗传多样性及其种间关系研究

应用RAPD标记技术对甘肃省境内的23种忍冬属(Lonicera Linn．)植物的遗传多样性及其种间关系进行了探讨。从34个随机引物中共选出9个多态性和重复性较好且谱带清晰的引物,这9个引物扩增出的DNA片段大多在300～3000bp之间,所形成的多态性位点数差距较大。POPGENE 1．31软件分析结果表明：甘肃省忍冬属植物具有较为丰富的遗传多样性,其多态性比率为71．93％,Shannon多样性指数与Nei指数分别为0．3230和0．2086。Nei‘s遗传距离和UPGMA分析结果显示,23种忍冬明显地聚为2大类,其下又有较多分支,即隶属于同一亚组或相近亚组的不同种基本归为一类,其种间关系与传统的形态学分类结果基本一致。但也有个别种的归属及种间关系稍有变化,如形态学上差异较大的毛药忍冬和毛花忍冬在本研究中聚在一起。这可能与不同的分类水平有关。     

4种红豆杉属植物遗传多样性和遗传关系的RAPD分析

采用RAPD标记研究了分属于4种红豆杉属(Taxus Linn.)植物的68个单株的遗传多样性,并采用UPGMA方法分析68个单株的遗传关系.结果表明:12条RAPD引物共扩增出109条带,其中多态性条带108条,多态性条带百分率为99.1％;平均每条引物扩增出9.1条带.南方红豆杉[T.wallichiana var.mairei (Lemée et Lévl)L.K.Fu et Nan Li.]种内的多态性条带百分率和观察等位基因数均最高;欧洲红豆杉(T.baccata Linn.)种内的有效等位基因数、Nei's基因多样度和Shannon's信息指数均最高;须弥红豆杉(T.wallichiana Zucc.)种内的各项遗传多样性指数均最低.供试4种植物的种内遗传多样度、种间遗传多样度、基因流和种间遗传分化系数分别为0.1745、0.358 6、0.401 7和0.554 5,表明55.45％的遗传变异发生在种间.南方红豆杉和须弥红豆杉遗传距离最近;曼地亚红豆杉(Taxus×media Rehd.)和须弥红豆杉的遗传距离最远.通过聚类分析可将68个单株分为3组,欧洲红豆杉的18个单株和曼地亚红豆杉的18个单株分别各自聚为1组;须弥红豆杉的16个单株和南方红豆杉的16个单株聚为1组,其中须弥红豆杉的16个单株和南方红豆杉的16个单株又各自聚为1个亚组,且南方红豆杉的雌、雄单株也分别聚在同一分支上,表明须弥红豆杉和南方红豆杉遗传关系较近,而欧洲红豆杉与其他3种植物的遗传关系较远.     

Comparative genomics of the medicinal plants Lonicera macranthoides and L. japonica provides insight into genus genome evolution and hederagenin-based saponin biosynthesis

Lonicera macranthoides (LM) and L. japonica (LJ) are medicinal plants widely used in treating viral diseases, such as COVID-19. Although the two species are morphologically similar, their secondary metabolite profiles are significantly different. Here, metabolomics analysis showed that LM contained ~86.01 mg/g hederagenin-based saponins, 2000-fold higher than LJ. To gain molecular insights into its secondary metabolite production, a chromosome-level genome of LM was constructed, comprising 9 pseudo-chromosomes with 40 097 protein-encoding genes. Genome evolution analysis showed that LM and LJ were diverged 1.30–2.27 million years ago (MYA). The two plant species experienced a common whole-genome duplication event that occurred ∼53.9–55.2 MYA before speciation. Genes involved in hederagenin-based saponin biosynthesis were arranged in clusters on the chromosomes of LM and they were more highly expressed in LM than in LJ. Among them, oleanolic acid synthase (OAS) and UDP-glycosyltransferase 73 (UGT73) families were much more highly expressed in LM than in LJ. Specifically, LmOAS1 was identified to effectively catalyse the C-28 oxidation of β-Amyrin to form oleanolic acid, the precursor of hederagenin-based saponin. LmUGT73P1 was identified to catalyse cauloside A to produce α-hederin. We further identified the key amino acid residues of LmOAS1 and LmUGT73P1 for their enzymatic activities. Additionally, comparing with collinear genes in LJ, LmOAS1 and LmUGT73P1 had an interesting phenomenon of ‘neighbourhood replication’ in LM genome. Collectively, the genomic resource and candidate genes reported here set the foundation to fully reveal the genome evolution of the Lonicera genus and hederagenin-based saponin biosynthetic pathway.     

螅状独缩虫(Cachesium polypinum)遗传多样性的RAPD分析

用随机扩增多态ＤＮＡ（ＲＡＰＤ）技术对武汉的汉口（ＣＰ－１）、汉阳（ＣＰ－２）和武昌（ＣＰ－３）三个地区缘毛类的螅状独缩虫（Ｃａｃｈｅｓｉｕｍ ｐｏｌｙｐｉｎｕｍ）进行了遗传多样性分析。结果表明：这种动物存在广泛的变异,三个地域群体之间的遗传相似度为０．６５２２－０．７３８５（平均值为０．６９２１）,各群体之间遗传相似度大小依次为：ＣＰ－２－ＣＰ－３〉ＣＰ－１－ＣＰ－２〉ＣＰ－１－ＣＰ－３。本文对     

天然红松群体遗传多样性的RAPD分析

用RAPD技术分析了分布于中国东北的3个红松（Pinus koraiensis Seib.et Zucc.）天然群体的遗传多样性及群体间的遗传分化。38个随机引物共检测到241个可重复的位点,其中多态位点139个,占总位点的57.68%。Shannon信息指数和Nei指数的统计结果都表明,红松种内的遗传变异主要存在于群体内,凉水群体的遗传多样性水平高于黑河、虎林群体。群体内遗传相似度为0.927,群体间为0.845。红松现阶段对偏低的遗传多样性水平与第四纪冰期所遭受的严重打击和人类近期的干扰有较大关系。     

Geographic patterns of genetic diversity in Poulsenia armata (Moraceae): implications for the theory of Pleistocene refugia and the importance of riparian forest

Abstract. Tropical forests are species-diverse communities, but we know very little about the geographical distribution of genetic diversity within a species. During the late Pleistocene, lower temperatures and rainfall reduced the distribution of tropical wet forests, and in Central America lowland species may have been limited to riparian habitats. Approximately 12,000 years bp , temperature and rainfall increased in Central America, the distribution of wet forest species expanded, and today the distribution of some species extends into southern Mexico. The distribution of genetic diversity, based on RAPD markers, among ten populations of Poulsenia armata (Miq.) Standl. (Moraceae) suggests that these populations did not originate from a single refugium or region in the late Pleistocene. The Central American populations had high genetic diversity and unique bands giving support to the hypothesis that populations of P. armata occurred in Central American during the late Pleistocene. The majority of genetic diversity was partitioned among populations and there was no geographical relationship among populations, suggesting that these populations were isolated for a long period and there has been little gene flow. Populations of P. armata may have persisted in riparian zones along the Caribbean coast during the late Pleistocene. Given that riparian forest can support high levels of biodiversity in ecological time, and they have played an important role during periods of climate change over geological time, their conservation is of utmost importance particularly with the threat of a rapid shift in climatic patterns.     

Low genetic variability and strong differentiation among isolated populations of the rare steppe grass Stipa capillata L. in Central Europe

Stipa capillata L. (Poaceae) is a rare grassland species in Central Europe that is thought to have once been widespread in post‐glacial times. Such relict species are expected to show low genetic diversity within populations and high genetic differentiation between populations due to bottlenecks, long‐term isolation and ongoing habitat fragmentation. These patterns should be particularly pronounced in selfing species. We analysed patterns of random amplified polymorphic DNA (RAPD) variation in the facultatively cleistogamous S. capillata to examine whether genetic diversity is associated with population size, and to draw initial conclusions on the migration history of this species in Central Europe. We analysed 31 S. capillata populations distributed in northeastern, central and western Germany, Switzerland and Slovakia. Estimates of genetic diversity at the population level were low and not related to population size. Among all populations, extraordinarily high levels of genetic differentiation (amova : φ_ST = 0.86; Bayesian analysis: θ^B = 0.758) and isolation‐by‐distance were detected. Hierarchical amova indicated that most of the variability was partitioned among geographic regions (59%), or among populations between regions when the genetically distinct Slovakian populations were excluded. These findings are supported by results of a multivariate ordination analysis. We also found two different groups in an UPGMA cluster analysis: one that contained the populations from Slovakia, and the other that combined the populations from Germany and Switzerland. Our findings imply that S. capillata is indeed a relict species that experienced strong bottlenecks in Central Europe, enhanced by isolation and selfing. Most likely, populations in Slovakia were not the main genetic source for the post‐glacial colonization of Central Europe.     

柱花草RAPD反应体系的建立及其8个品种遗传多样性分析

采用两种不同的方法分别从柱花草嫩叶及种子萌发芽中提取了高质量的DNA ,并对柱花草RAPD反应中的各组分浓度及热循环因素进行优化 ,建立了柱花草RAPD反应的最佳条件。在此基础上 ,用 2 0条随机引物对 8个柱花草品种进行了RAPD扩增 ,结果表明 ,其多样性达 5 1 .9% ,品种间的遗传相似系数在 0 .5 3～0 .88之间 ;根据非加权成对平均数法 (UPGMA)进行分类 ,获得了品种聚类树形图 ,8个柱花草品种均被明显分开。     

我国部分白菜型油菜 RAPD 的研究

本研究用RAPD技术和统计学方法,对以湖南和湖北省油菜为主的34个白菜型油菜品种的遗传多样性进行了分析。根据离差平方和,用Ward's聚类方法进行聚类。结果表明：白菜型油菜的遗传变异与生态地理分布有密切的关系;湖南和湖北两省的白菜型油菜品种存在广泛的遗传变异;在DNA水平上可将所分析的34个品种分成8个类群。作者对研究结果在遗传育种中的应用进行了讨论。     

外源DNA导入小麦的RAPD验证及遗传分析

将外源DNA特别是牛胸腺DNA转移给普通小麦,对在其后代中选育出的矮杆变异体进行了RAPD分子验证及其遗传学分析研究,获得了3个主要结果：（1）对变异体D111,受体814527,供体矮孟牛I型进行的RAPD验证中,通过137个引物由5个引物检测出了DNA的多态性,表明矮秆变异体D111的出现可能是供体的片段DNA进入了受体并得到稳定遗传。（2）对变异体D011,D1453,受体814527,供体牛胸腺DNA进行的RAPD验证中,在供试的180个引物中,变异体,受体扩增产物的带型绝大多数一致而与供体则完全不一致,其中有很少引物对变异体和受体扩增产物的带型表现不同,还有个别引物对变异体扩增产物的带型与供体的个别带一致,由此说明亲缘关系极远的牛胸腺DNA导入受体引起的变异更为广泛和复杂;（3）3个矮秆变异体的遗传分析表明,控制其株高的基因位于核基因组,在杂种后代中表现了明显降低株高的作用,其杂种后代的某些农艺性状也表现良好,因此,利用它们进行杂交育种或在杂种优势的利用上,都将是有较好应用价值前途的新矮源。     

蒙古冰草遗传多样性的RAPD分析

采用RAPD技术对蒙古冰草（Agropyron mongolicum Keng)6个天然居群和2个栽培品种（系）的45个个体进行了遗传多样性检测。17个引物共检测到101个位点,其中多态位点81个,占80.2%,相对于其它小麦族植物,显示出了较高的遗传多样性,多样性指数（DC）分析的结果表明,遗传多样性在居群内和居群间的分布存在不均衡现象,但总体来看,居群内的遗传变异高于居群间,这是由蒙古冰草异花,风媒传粉的外繁育系统所决定的,在天然居群与栽培品种（系）间,前者的DC值为0.250,后者的DC值为0.181,而且前者的平均遗传距离（0.290)也高于后者（0.213),表明天然居群间的遗传分化大于栽培品种（系）,这与天然居群间环境的异质性密切相关,同时也反映了栽培品种（系）间较近的亲缘关系,UPG-MA聚类分析的结果表明,8个居群基本上可被分为与其生境特点及生长条件相适应的3个类群,反映了自然选择及人工选择对居群间遗传分化的巨大影响。     

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.     

野古草种群克隆的遗传变异和遗传结构

用酶电泳法和同工酶分析对东北松嫩草原西北部野古草种群克隆遗传变异性和种群遗传结构做了探讨。讨论了遗传多样性、地理距离和遗传距离之间的关系、大种群和小种群的遗传变异性和种群间的基因流 ;种群间 ,包括大种群和小种群间基因流、遗传和地理距离对遗传多样性的影响、昆虫和风传粉、种群籽苗的补充、遗传多样性的发生和保持 ,自交不亲和性和无性繁殖及体细胞突变     

山西不同地域菜粉蝶RAPD遗传多样性

采用RAPD技术分析了山西省菜粉蝶5个地域种群间的遗传多样性和遗传关系,用筛选出的12对引物扩增共得到143条带,其中127(88.8%)条带具有多态性,5个种群变异程度由大到小的顺序为:大同的(76.3%)＞太原的(74.7%)＞长治的(74.5%)＞代县的(73.7%)＞夏县的(70.7%).Shannon's信息指数分析结果显示大多数变异发生在种群内(73.7%).种群间的Nei's遗传距离较低(均＜0.1).用UPGMA和 Neighbor-joining做的基于RAPD标记的Nei's遗传距离的聚类图显示,各种群内的个体首先聚在一起,种群之间有一定分化,5个地域种群间较远距离的代县种群与夏县种群遗传关系最近并优先相聚.经过对试验结果的分析讨论认为:环境类型及其生态条件对山西省菜粉蝶地域种群的遗传多样性和遗传变异产生了重要的影响,其中农药的施用对菜粉蝶种群遗传结构的影响有可能是深刻的.     

Domestication and the distribution of genetic variation in wild and cultivated populations of the Mesoamerican fruit tree Spondias purpurea L. (Anacardiaceae)

Domestication occurs as humans select and cultivate wild plants in agricultural habitats. The amount and structure of variation in contemporary cultivated populations has been shaped, in part, by how genetic material was transferred from one cultivated generation to the next. In some cultivated tree species, domestication involved a shift from sexually reproducing wild populations to vegetatively propagated cultivated populations; however, little is known about how domestication has impacted variation in these species. We employed AFLP data to explore the amount, structure, and distribution of variation in clonally propagated domesticated populations and sexually reproducing wild populations of the Neotropical fruit tree, Spondias purpurea (Anacardiaceae). Cultivated populations from three different agricultural habitats were included: living fences, backyards, and orchards. AFLP data were analysed using measures of genetic diversity (% polymorphic loci, Shannon's diversity index, Nei's gene diversity, panmictic heterozygosity), population structure (F(ST) analogues), and principal components analyses. Levels of genetic variation in cultivated S. purpurea populations are significantly less than variation found in wild populations, although the amount of diversity varies in different agricultural habitats. Cultivated populations have a greater proportion of their genetic variability distributed among populations than wild populations. The genetic structure of backyard populations resembles that of wild populations, but living fence and orchard populations have 1/3 more variability distributed among populations, most likely a reflection of relative levels of vegetative reproduction. Finally, these results suggest that S. purpurea was domesticated in two distinct regions within Mesoamerica.