17份苎麻栽培品种的RAPD分析

苎麻属于荨麻科是起源于我国的一种纤维与饲料作物,主要分布于热带、亚热带,少数达温带。我国的苎麻种质资源十分丰富,在苎麻品种资源的形态特征、农艺性状等方面已有较多的研究,建立了基于形态特征的分类系统。由于苎麻是以无性繁殖为主的宿根型作物,在遗传上高度杂合,自交难以获得纯系,加之其染色体小,从细胞遗传学的水平进行遗传背景的研究较为困难,因而人们对苎麻品种的了解大多局限于形态特征与农艺性状,在育种亲本的选配上具有较大的盲目性。通过对RAPD指纹图谱的统计分析,可以对其遗传背景与亲本选配提供DNA分子水平的依据。本研究选用在地理来源、形态特征和农艺性状上有一定差异的17份苎麻品种,利用RAPD分子标记构建其基因组指纹图谱,为苎麻种质资源研究和遗传育种提供更多的依据。     

姜品种遗传多样性的RAPD分析

利用RAPD技术对20个姜(Zingiberofficinale)品种进行了遗传多样性的研究。从200多个引物中筛选出25个有效引物,共扩增出171条DNA带,其大小分布在100￣3500bp之间,其中111条为多态性,约占总数的64.91%,平均每个引物的扩增带为6.8条。利用25个有效引物扩增的DNA带数计算出品种间的J系数,并进行UPGMA聚类分析,在此基础上,建立了中国姜品种亲缘关系系统树。在相似性系数0.67处,20个品种分为Ⅰ、Ⅱ、Ⅲ和Ⅳ类。Ⅰ类可分为A、B和C组;Ⅳ类可分为D和E组。其中,A组可再分为A1和A2亚组;B组可再分B1和B2亚组。各亚组内相似性系数较大,表明它们之间的亲缘关系较近,但也存在着一定的差异。     

白骨壤种群遗传变异及分化的生态分析研究

白骨壤（Auicennia marina)为红树植物。采用垂直板型聚丙烯酰胺凝胶电泳测定了5个白骨壤种群遗传多样性、遗传分化,分析了白骨壤种群的样地气候和土壤理化指标。研究结果表明,环境因子与白骨壤种群的Aat-1A,Aat-1D,Me-1B,Me-1C4个等位基因相关性显著,说明环境因子对这4个等位基因具有选择压力,他们的变化与环境变量有关。     

大豆空间诱变突变体的RAPD分析

本研究应用RAPD技术在分子水平进行大豆空间诱变突变体的差异性分析,为大豆空间诱变育种提供理论基础。首次应用RAPD标记对大豆空间诱变的12个品系及4个原始对照种进行多态性分析。随机选用的70个RAPD引物对原始对照种及12个空间诱变品系进行扩增,共获得247条DNA谱带,其中多态性谱带39条,总多态性位点比率为15.8%,品系间多态性位比率在1.43%~10%之间,扩增片段长度在250-2100bp之间。因此,通过空间诱变能够在DNA水平上导致大豆遗传物质变异,并且RAPD是一种研究植物空间诱变材料的较有效的分子生物学方法。     

华东竹黄菌不同居群遗传分化的RAPD分析

为了解竹黄地理居群间的遗传分化,本研究采用随机引物扩增多态性DNA分子标记技术对江苏、安徽和浙江3省的8个居群共32个竹黄样本进行了遗传多样性分析。从50个RAPD引物中筛选得到了5个随机引物,对供试材料的DNA进行扩增,共检测出77个位点,其中多态性位点52个,多态性位点比率为67.53%。UPGMA聚类分析结果表明,这8个居群分为三类：安吉居群、临安居群、宜兴居群、广德居群和泾县居群聚为一类;宁国居群和休宁居群聚为一类;淳安居群单独为一类。遗传多样性分析表明8个竹黄居群中,淳安居群的遗传多样性水平最高,安吉居群的遗传多样性水平最低。Nei＇s基因多样性指数和Shannon信息指数均表明竹黄物种水平的遗传多样性高于居群水平。     

桑树有性杂交后代与双亲基因组DNA的RAPD分析初报

用６个随机引物对桑５个杂交亲本和５个杂交后代基因组ＤＮＡ进行ＲＡＰＤ分析,它们均表现出丰富的ＤＮＡ多态性,反映了桑树遗传背景多种性和品种间的差异性。杂交后代与双亲间的基因组ＲＡＰＤ图谱比较,不同杂交组合和不同引物间有较大差异,５个Ｆ１代的ＤＮＡ片段绝大多数与双亲或单亲相同,但杂交后工中也出现了少数特异性片段。     

快中子辐照紫花苜蓿的生物学效应与RAPD分析

采用直线加速器产生3.60×1011、7.10×1011和3.54×1012/cm2 3种辐照注量的快中子处理肇东苜蓿干种子,对其进行种子发芽试验、幼苗生长和RAPD分子标记分析。研究表明,经3种注量快中子处理后,肇东苜蓿种子发芽势和发芽率显著高于对照;幼苗的苗高和根长小于对照,随着快中子处理注量的增加,幼苗苗高降低和...     

超低温小麦种子和幼苗保存及遗传变异分析

 以小麦（Triticum aestivum L.）品种周98165和开18的种子与幼苗为材料,对它们超低温（液氨中）保存前后的发芽和成活率及田间生长指标进行了研究,并采用AFLP和MSAP技术对其遗传稳定性作了初步探讨。结果表明,小麦种子经超低温保存后,其发芽率和成活率与对照相比有一定的差异,但田间生长,除分蘖数稍低于对照外,其他生长指标与对照相比没有明显区别。而超低温保存后的幼苗,各项生长指标与对照均有显著差异。AFLP技术分析了超低温保存前后的样品,同一品种不同处理间的AFLP带型一致,统计的1500多条带中未见明显差异带型,表明在超低温保存前后无论是种子还是幼苗,其基因组DNA序列均没有发生变异。进一步用MSAP技术分析了超低温保存后的样品的甲基化水平,13对引物共扩增出590多条清晰的带,与对照相比,超低温保存后的材料均产生了不同程度的甲基化变化。其中变异带最多的达83条,变异率高达13.67%,且脱甲基化变化是主要趋势。     

RAPD analysis of genetic relationships of seven flax species in the genus Linum L

The wild progenitor of the cultivated flax (Linumusitatissimum L.) has been long hypothesized to beL. angustifolium Huds., largely fromseveral phytogeographic cytogenetic and phenotypic studies, but no molecularstudies on the issue are found. In this study, we genotyped 12 flax accessionsrepresenting seven flax species in the genus Linum with 527RAPD loci from 29 informative RAPD primers and analyzed their geneticrelationships with simple matching, Dice's and Jaccard's similaritycoefficients. Large RAPD variations were found among the flax species.L. usitatissimum andL. angustifolium had a higher RAPDsimilarity than the other pairs of flax species and these two species wereconsistently clustered in the same group with all of the similarity coefficientsused. This molecular finding provides an additional support for the hypothesisof L. angustifolium as the wildprogenitor of cultivated flax.     

Characterization of genetic variation and relationships among Choix germplasm accessions using RAPD markers

Choix, a plant in the tribe Maydeae of the grass family, has been cultivated in Asia for several thousand years. It is a potential gene resource for improvement of other cereal crops because of its nutritional value and tolerance to stress. Genetic variation and relationships among 21 Choix lachryma-jobi L. accessions were characterized by random amplified polymorphic DNA (RAPD) markers. A total of 205 DNA fragments across all materials were amplified with 31 random primers, averaging 6.61 per primer. Among amplified fragments, 115 showed polymorphism averaging 3.71 per primer. Of amplified markers, 56.1% were polymorphic, indicating considerable variation at the DNA level among these accessions. Some fragments were accession-specific. Pair-wise genetic similarity (GS) among 21 accessions ranged from 0.809 to 0.301. The 21 accessions clustered into two major groups. Three exotic Choix accessions clustered together. Three other Choix accessions, collected from Guangxi, China, clustered into a cohesive subgroup. Four wild types of Choix clustered into the same subgroup. These results indicated that the classification by RAPD data reflected the differences in geographic origins and evolution in Choix.     

Genetic diversity in African cucumber (Cucumis sativus L.) provides potential for germplasm enhancement

Genetic diversity among 26 cucumber (Cucumis sativus L. var. sativus) accessions from five African countries [Algeria (1), Egypt (21), Ethiopia (2), Kenya (1), and Libya (1)] present in the U.S. National Plant Germplasm System (NPGS) were examined by assessing variation at 71 polymorphic random amplified polymorphic DNA (RAPD) loci. Genetic distances (GD; simple matching coefficient) were estimated among these African accessions and a reference array (RA) of 21 accessions representative of the genetic variation in cucumber. GD among African accessions ranged between 0.41 and 0.97. GD among accessions in the reference array ranged between 0.36 and 0.88. Multivariate analysis identified three distinct groupings (1–3) of African accessions; Group 1 contained 21 accessions (Egypt, Ethiopia and Libya), Group 2 consisted of two accessions (Kenya, Algeria), and Group 3 possessed three accessions (Egypt). These groupings were distinct from each other (P > 0.001). Accessions in Group 1 differed genetically from all other accessions examined (P > 0.01), and accessions in Groups 2 and 3 were uniquely associated with several RA accessions. While GD among accessions in Group 1 ranged between 0.52 and 0.90, distances among Group 2 accessions varied between 0.93 and 0.97. The GD between the two accessions in Group 3 was 0.65. An accession from Syria (PI 181874) and from one Turkey (PI 199383) were genetically more similar to accessions in Group 1 than to other accessions in the RA. Likewise, accessions in Group 2 were genetically similar to two RA accessions from China and a European glasshouse cucumber line, and Group 3 accessions showed genetic affinities with the U.S. market class cultivar Dasher II. Data suggest that some Egyptian accessions (Group 1) possess unique genetic variation, that this germplasm has potential for broadening the genetic base of commerical cucumber, and that further collection of African germplasm is likely to enhance genetic diversity of cucumber in NPGS.     

Genetic variation in captive population of chinese alligator, Alligator sinensis, revealed by random amplified polymorphic DNA (RAPD)

Chinese alligator (Alligator sinensis) is an endemic species in China. The likely extinction of it in the wild has been recognised. To prevent this species becoming extinct, the Anhui Research Centre of Chinese Alligator Reproduction (ARCCAR) was established in Xuanzhou, Anhui Province in 1979, where has been established the largest captive population of Chinese alligator (XZSP) in the world. Another farm (CXSP) was established by villagers in Changxin, Zhejiang Province. The results of an investigation of the two captive subpopulation structures by genetic analysis are presented in this paper. We examined the genetic variation in the two captive subpopulations using RAPDs. Thirty-one random primers were selected among 199 random primers screened. A total of 193 reproducible RAPD fragments were scored among 43 individuals, of which 21 (10.88%) were polymorphic. The genetic distances between 43 individuals ranged from 0 to 0.0376 with average of 0.0104±0.0055 S.E. The genetic similarity in CXSP (0.9948±0.0029 S.E.) was higher than that in XZSP (0.9894±0.0055 S.E.). The founder effect is a possible explanation for very low genetic variation in CXSP. Analysis of the RAPD data showed that the mean phenotypic band frequencies of each polymorphic loci was 0.6656±0.3730 S.E. The lowest phenotypic band frequency (0.0233) was found in four of those polymorphic loci. There was no genetic difference between the two subpopulations (D_ij=0.0009). According to the dendrogram and the distribution of polymorphic fragments in two subpopulations, CXSP originated genetically from XZSP. This paper summarises a preliminary research on genetic structure in populations of Chinese alligator. Although there is higher genetic similary (0.9896±0.0055 S.E.) in captive population of A. sinensis, we did not determine whether or not loss of genetic variation had occurred in relation to a wild control population. The data of malformed offspring will be collected carefully, and wild samples be added to set up a control population in future study.     

Ploidic and Molecular Analysis of ‘Morado de Huetor’ Asparagus (Asparagus officinale L.) Population; A Spanish Tetraploid Landrace

A study has been conducted into the genetic variation analysis of the tetraploid asparagus landrace ‘Morado de Huetor’ and its relationship with current commercial cultivars using Random Amplified Polymorphic DNA (RAPD) molecular markers. The presence of different ploidic levels in the ‘Morado de Huetor’ landrace has been also studied using cytogenetic analysis. Ten decamer oligonucleotides were used to obtain RAPD markers and to characterise 52 individuals of ‘Morado de Huetor’, 7 of the tetraploid cultivar ‘Purple Passion’, and 55 of 5 diploid hybrid commercial cultivars. Jaccard similarity index was calculated and a cluster analysis using UPGMA (Unweighted Pair-Group Method using Arithmetic Average) was performed. Tetraploid asparagus, ‘Morado de Huetor’ and ‘Purple Passion’, were well differentiated from the diploid ones showing a higher genetic variability. This result suggests a different origin for tetraploid and diploid asparagus varieties. Within the diploid cultivars a variety distribution was obtained. A specific monomorphic band (OPB20₈₈₃) was found in tetraploid varieties. Within the diploid cultivars, two bands (OPB20₈₃₀, OPC15₇₀₅) can be used to distinguish between the hybrid cultivars used in this study. Tri-, penta-, hexa-, and octoploid plants were found in ‘Morado de Huetor’. The origin of these ploidic levels is discussed and their use in the development of new varieties is proposed. In conclusion, ‘Morado de Huetor’ is a genetic resource that could be used to increase the narrow genetic background reported in diploid asparagus cultivars.     

Genetic variation within and among species of five sections of the genus Arachis L. (Leguminosae) using RAPDs

Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However, higher polymorphism was found in the section Trierectoides and in one accession of A. major, indicating that generalizations should be avoided and each species should be analyzed in order to establish collection and maintenance strategies.