应用SRAP标记分析黄瓜的遗传差异

利用49对SRAP引物对4种不同类型28份黄瓜种质资源进行了遗传差异分析.结果表明,有35对引物扩增出多态性,在28份资源间共产生724条扩增带,平均每对引物组合产生20.69条;共检测出337个多态性位点,多态性比率为46.5%,每对引物平均为96.3个.利用NTSYS软件分析遗传相似系数,UPGMA方法聚类分析表明,28份资源可聚为两大类.试验结果表明SRAP标记位点多,重复性好,可以揭示不同类型黄瓜种质之间的遗传基础.     

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。     

野生扁蓿豆种质资源AFLP遗传多样性的分析

本研究采用AFLP标记对河北省、辽宁省、吉林省、山西省、内蒙古自治区和西藏自治区的10份野生扁蓿豆居群进行遗传多样性分析。从64对AFLP引物组合中,筛选出8对扩增条带清晰、多态性高的引物组合,8对引物共扩增出640个条带,其中多态性条带有472个,多态性位点百分率为73.8%;Nei's基因多样性指数平均为0.157,Shannon's多态性信息指数平均为0.099;居群间遗传相似系数(GS)平均值为0.827。聚类和主成分分析可将10个扁蓿豆居群聚为3大类,结果与居群的地理分布大致相符,呈一定的地域性分布规律。由此可见,AFLP分子标记研究结果能较好地揭示扁蓿豆居群间的遗传多样性。对我国各地的野生扁蓿豆资源的广泛收集、评价和基因资源的保护有重要的意义。     

新疆枸杞种质资源遗传多样性分析及DNA指纹图谱构建

利用SCoT分子标记对新疆枸杞种质资源进行遗传多样性分析和DNA指纹图谱构建,为杂交育种和种质鉴定提供理论依据。结果显示:9条SCoT引物扩增出条带256条,其中219条为多态性条带,多态性比率达85.62%,多态性信息含量(PIC)值变化范围在0.77~0.91之间,平均值为0.85,观测等位基因数(Na)、有效等位基因数(Ne)、Nei's基因多样性指数(H)和Shannon信息指数(I)的平均值分别为1.8562、1.4350、0.2611、0.3989,聚类分析表明,遗传相似系数变化范围在0.5938~0.8398之间,在遗传相似系数为0.66和0.71处,可将30份材料分别分为2大类和4个亚类,主坐标分析结果和聚类结果基本一致,同时利用5条多态性SCoT引物构建了30份材料的DNA指纹图谱。新疆枸杞种质资源遗传多样性水平较高,且SCoT分子标记适于新疆枸杞种质资源遗传多样性分析和DNA指纹图谱构建,该研究结果为新疆枸杞种质资源评价、鉴定和新品种选育奠定了基础。     

利用SCoT分析柳枝稷遗传资源的多样性

本研究利用SCoT标记对96份柳枝稷种质的亲缘关系和遗传变异进行了研究。筛选出20条引物对96份供试材料进行PCR扩增,共获得445条带,其中多态性条带402条,平均多态性条带比率(PPB)达90.31%,多态性信息含量(PIC)为0.166~0.410,平均值为0.332,标记指数(MI)为10.20。遗传相似系数(GS)为0.498~0.912,平均值为0.688。表明SCoT标记能够揭示柳枝稷种质间的遗传变异。通过UPGMA分析表明,96份种质资源聚为高地型和低地型两大类。经POPGENE1.32软件分析结果显示:96份柳枝稷基因多样性指数(H)为0.285,Shannon指数(I)为0.431,表明供试的种质间遗传多样性丰富,遗传多样性水平高。经AMOVA 1.55方差分析揭示:96份柳枝稷生态型内的遗传变异占总变异的72.85%,生态型间遗传变异占总变异的27.15%,结果表明ScoT可用于柳枝稷遗传多样性研究,该研究结果可为柳枝稷种质资源的进一步开发利用提供重要信息。     

基于SSR标记的彩色马铃薯亲缘关系分析及指纹图谱构建

为了探究彩色马铃薯种质资源的遗传背景,该试验共选用22对SSR标记引物,对33份彩色马铃薯品种(系)进行遗传多样性分析以及指纹图谱构建。结果表明:(1)22对引物可扩增得到95个等位位点,其中82个为多态性位点,多态性比率达到86.31%;多态信息量(PIC)从0.168 7(STM1053)到0.991 9(STI033),平均为0.8411。(2)UPGMA聚类分析表明,在相似系数0.71处,33份供试材料分为4个主要聚类群,不同聚类群之间具有较大的遗传差异。(3)利用STM0031、STM0030、STI014、STM1029、STI001共5对SSR标记引物构建了33份彩色马铃薯材料的分子标记指纹图谱。该研究结果为彩色马铃薯育种亲本组配奠定了理论基础,有助于彩色马铃薯种质资源的快速鉴定。     

棉花遗传多样性SCoT和SRAP标记的研究及比较分析

利用SCoT和SRAP两种分子标记技术对30份彩色棉与白色棉种质资源,进行遗传多样性研究。用29对SRAP引物组合和26个SCoT引物分别对供试棉花的基因组DNA进行扩增。SCoT引物共扩增出163条带,多态性比率为61.96%,遗传相似系数GS值变化范围为0.5405～0.9972。SRAP引物组合共扩增条带1067条,多态性比率仅为14.1%,遗传相似系数GS值变化范围为0.5415～0.9109。两种标记系统得到了相似但并不完全相同的聚类图,2种标记方法间存在显著相关性(r=0.5518,P<0.05)。结果表明,SRAP与SCoT标记均适用于棉花种质的遗传多样性分析,且SCoT的标记指数MI高于SRAP标记,为SCoT这种新兴的标记技术在棉花育种中的应用提供了重要的依据。     

不同生态区罂粟种质的遗传多样性ISSR分析

为了揭示罂粟种质的遗传多样性,利用ISSR分子标记进行遗传多样性研究,从100条随机引物中筛选出9条多态性引物对所有样品扩增,共检测到109个等位变异位点,引物等位位点数在9～16之间,平均每条引物有12个等位变异,其中,引物807的等位位点最多,为16个。引物等位位点多态性信息量PIC值为0.77～0.92。其中引物807的PIC值最大(0.92),引物847的PIC值最小(0.77),遗传相似系数在-0.452～0.981之间,且明显聚为2个类群;亲缘关系和地理分布呈一定的相关性,但没有形成明显的地理变异模式;本研究将为罂粟种质资源科学有效利用提供理论依据。     

中国食用向日葵种质资源遗传变异的RAPD及AFLP分析

本研究采用RAPD和AFLP方法对23个中国不同地区的食用向日葵(Helianthus annuus L.)骨干品种进行了遗传变异分析,同时对两种标记系统进行了比较.26个RAPD引物产生了总计192条DNA条带,大小分布于0.26 kb～1.98 kb之间,其中165条(86.12%)具有多态性,每条引物产生DNA条带的平均数为7.38.8对AFLP引物组合共产生了576条带,分布于100 bp～500 bp之间,其中的341条具有多态性,多态百分率为76.00%,每对引物组合产生DNA条带的平均数为72.RAPD方法检测到的每位点有效等位基因数(1.76)大于AFLP(1.65),AFLP标记位点的平均多态性信息量(PIC)(0.38)低于RAPD标记位点的PIC(0.41),但AFLP标记具有很高的多态性检测效率(Ai=38.52).用RAPD标记分析23个食用向日葵材料的亲缘关系,Nei氏相似性系数分布在47.84%～82.06%,平均相似性系数为0.649 5, 而采用AFLP的Nei氏相似性系数分布在54.15%～83.52%,平均相似性系数为0.688 4.RAPD数据的标准差为0.13,而AFLP数据的标准差为0.08.因此,采用RAPD和AFLP方法分析食用向日葵遗传变异,RAPD标记具有较低相似性系数和较高方差而AFLP则相反.源于两种不同标记的遗传相似性矩阵的相关系数为0.51,说明采用RAPD和AFLP系统分析食用向日葵遗传变异得到的结果有一定的相关性.无论采用RAPD还是AFLP标记进行聚类分析,都将23个不同基因型的食用向日葵材料分成了三个类群.     

胡麻种质资源遗传多样性及亲缘关系的SRAP分析

利用SRAP分子标记,对国内外5个不同地区161份胡麻种质资源的遗传多样性及亲缘关系进行研究,为胡麻育种提供科学依据。结果表明:(1)20对引物扩增出307个条带,其中有192个多态性条带,多态比率为62.54%,平均每对引物组合有9.60个多态性位点,每对引物的多态性信息量(PIC)为0.51~0.76,平均为0.61。(2)有效等位基因数(Ne)、香浓信息指数(I)和Neis遗传相似系数(H)在物种水平上分别为1.582 0、0.521 1和0.346 5,在群体水平上分别为1.491 1、0.431 1和0.286 3。(3)各群体遗传多样性指数表现为中国西北群体中国华北群体美洲群体亚洲群体欧洲群体。(4)聚类分析结果显示,在遗传相似系数为0.335 5处,将161份胡麻资源分为2大类;在0.455 0处,分为5个亚类,与国内外5个不同地区来源吻合。研究表明,中国西北地区胡麻品种(系)的遗传多样性最为丰富;地域是影响胡麻种质资源遗传多样性的主要因素;国内、外品种(系)间的遗传差异较大,表现出较远的亲缘关系。     

Analysis of Genetic Diversity in Pongamia [Pongamia pinnata (L) Pierrre] using AFLP Markers

In recent years, Pongamia has been considered as important renewable source of biodiesel, however not much molecular information is available in this species. Molecular characterization of this legume tree will enhance our understanding in improving the optimal yields of oil through breeding and enable us to meet the future demands for biodiesel. To assess the molecular genetic diversity in 46 Pongamia pinnata accessions collected from six different states of India, amplified fragment length polymorphism (AFLP) marker system was employed. Five AFLP primer combinations produced 520 discernible fragments, of which 502 (96.5%) were polymorphic. AFLP primer informativeness was estimated evaluating four parameters namely polymorphism information content (PIC), effective multiplex ratio (EMR), marker index (MI) and resolving power (RP). In total, 51 unique fragments were detected of which 19 unique fragments were observed with primer combination E-ACG / M-CTA. Although neighbour joining (NJ) method did not group accessions strictly according to their region of collection, a good level of genetic diversity was observed in examined germplasm. However, accessions collected from Karnataka showed comparatively higher diversity than accessions from other states. The diverse accessions identified in this study may be useful in Pongamia pinnata improvement to meet the future demands of biodiesel.     

AFLP analysis of genetic diversity of Jatropha curcas grown in Hainan, China

Amplified fragment length polymorphism (AFLP) was used to determine the genetic diversity among 38 populations of Jatropha curcas L. grown in a seed source trial in Hainan Province of China. The populations studied consisted of one source from Indonesia and 37 sources from the main cultivating areas of jatropha in China, viz. Guangdong (1), Guangxi (10), Guizhou (4), Hainan (6), Sichuan (8) and Yunnan (8). Nine AFLP primer combinations were used to generate a total of 246 fragments, of which 72 (26.99%) were polymorphic. Three-marker attributes: polymorphism information content (PIC), marker index (MI) and resolving power (RP), were all found to be reliable to determine the discriminatory power of the nine primer combinations. The Jaccard’s similarity coefficient showed a high similarity range from 0.866 to 0.977, suggesting a low genetic diversity among the 38 populations. The UPGMA-based dendrogram and biplot of a principal component analysis did not reveal a clear pattern of groupings by geographic locations of the seed sources; populations from across different provinces were mixing in the same groups. The low genetic diversity and a lack of variation pattern among the populations in China suggest that it is necessary to import new germplasm preferably from the species’ natural distribution range to broaden the genetic base for improvement program.     

AFLP assessment of genetic diversity among Indian Mucuna accessions

Amplified fragment length polymorphism (AFLP) marker was used to assess diversity in germplasm collection of Mucuna species which has gained tremendous attention in the recent past due to its promising nutritional, agronomic and medicinal attributes. Twenty five accessions comprising five species, collected from seven states of India were evaluated with twelve AFLP primer combinations that generated a total of 1,612 fragments with an average of 134 fragments per primer combination. The values of polymorphic information content (PIC), marker index (MI) and the resolving power (Rp) demonstrated the utility of the primer combinations used in the present study for discriminating the Mucuna accessions. UPGMA and Principal coordinate analysis (PCoA) of the genotypic data revealed clustering of accessions as per phenetic and genetic relationships. The Jaccard’s similarity coefficient values suggested good variability among the M. pruriens accessions indicating their utility in breeding programs. Molecular diversity presented in this study combined with the datasets on other morphological/agronomic traits will be highly useful for selecting appropriate accessions for plant improvement through conventional as well as molecular breeding approaches and for evolving suitable conservation strategies.     

Diversity analysis in Indian genotypes of linseed (Linum usitatissimum L.) using AFLP markers

AFLP fingerprinting of 45 Indian genotypes of linseed was carried out to determine the genetic relationship among them. Sixteen primer combinations produced 1142 fragments with 1129 as polymorphic and 13 as monomorphic fragments. Polymorphic fragments varied from 44 (E-ACA/M-CTA) to 94 (E-AGC/M-CAC) with an average of 70.6 fragments per primer combination. The frequency of polymorphism varied from 93.7% to 100% with an average of 98.8% across all the genotypes. The PIC value ranged from 0.19 to 0.31 with an average of 0.23 per primer combination. The primer pair E-AGC/M-CAC showed the maximum PIC value (0.31) followed by E-AGC/M-CAG (0.29), E-AAC/M-CAG (0.26) and E-AGC/M-CTA (0.25). Resolving power (RP) and marker index (MI) varied from 13.73 to 43.50 and 8.81 to 28.91 respectively. The Jaccard's similarity coefficient varied from 0.16 to 0.57 with an average of 0.26 ± 0.05. The maximum genetic similarities (57%) were detected between genotypes Him Alsi-1 and Him Alsi-2, followed by Him Alsi-1 and GS41 and GS41 and LC-54. The genotypes R-552, Himani, RKY-14, Meera, Indira Alsi-32 and Suyog were found to be more divergent genotypes. The NJ clustering grouped all the 45 genotypes into three major clusters. In general the genotypes of cluster III had high oil content and those of cluster I had low oil content. At the population level, within population variance was much higher than between populations variance.     

羊草种质基因组DNA的AFLP多态性研究

羊草是禾本科牧草之王 ,在当前我国西部生态建设和草原畜牧业发展中发挥着重要作用。用AFLP方法对2 7份我国不同地区分布的羊草 (Leymuschinensis (Trin .)Tzvel)材料进行了基因组DNA多态性分析 ,8对AFLP引物组合在 2 7个不同羊草基因型中共扩增出 5 37条带 ,产生出的DNA片段大小分布在 75bp - 5 30bp之间。其中单态性带 89条 ,占 16 .6 % ,多态性带 32 9条 ,占 6 1.3%。平均每对引物组合扩增的DNA带数为 6 6 .13,总的多态性比率为 78.84%。AFLP多态信息含量PIC值分布于 0 .0 - 0 .5之间 ,平均PIC值为 0 .2 16 ,出现的PIC最大值 (0 .5 )约占AFLP标记的 8.5 % ,说明羊草基因组DNA的多态性比较丰富。以 5 37个AFLP标记为原始数据 ,根据Nei和Li的方法对 2 7份羊草材料进行遗传变异和聚类分析的结果表明 :羊草种内有高频率的遗传变异发生 ,且与地理分布和生态环境密切相关 ;2 7份羊草不同基因型被划分为四大类群 ,不同类群相互间的遗传距离相对较大 ,在树状图中表现为较远的亲缘关系。对羊草种内遗传变异发生的原因和品种的形成进行了初步讨论。     

利用RFLP、SSR、AFLP和RAPD标记分析玉米自交系遗传多样性的比较研究

利用 ＲＦＬＰ、ＳＳＲ．ＡＦＬＰ和ＲＡＰＤ ４种分子标记方法研究了 １５个玉米（Ｚｅａ ｍａｙｓ Ｌ．）自交系的遗传多样性,同时对４种标记系统进行比较。在供试材料中筛选到具多态性的ＲＦＬＰ探针酶组合５６个,６６对ＳＳＲ引物,２０个ＲＡＰＤ引物和９个ＡＦＬＰ引物组合,分别检测到多态性带１６７、２０１、８７和１０８条。ＳＳＲ标记位点的平均多态性信息量（ＰＩＣ）最大（０．５４）,ＡＦＬＰ标记位点最小（０．３６）,但ＡＦＬＰ标记具有最高的多态性检测效率（Ａｉ,３２．２）。４种分子标记所得遗传相似系数相关性显著,比较相关系数表明 ＲＡＰＤ可靠性较低。依据 ４种分子标记结果将 １５个供试自交系划分为塘四平头、旅大红骨、兰卡斯特、瑞德和ＰＮ共５个类群,与系谱分析基本一致。认为ＳＳＲ和ＲＦＬＰ两种分子标记方法适合进行玉米种质遗传多样性的研究。     

AFLP在橡胶树优异种质研究中的应用

采用377DNA测序仪（P.E.Corp.)用AFLP技术对25种分别具有高产／低产、抗白粉病／感白粉病、抗寒／不抗寒、死皮／不死皮性状的橡胶树（Hevea brasiliensis Mull.Ary)无性系（其中Wickham种质15种,Amazon野生橡胶树种质10种）进行了指纹图谱分析,从64对引物组合中选出2对引物组合构建了所有被研究种质的指纹图谱。2对引物共扩增出518条带,多态性比率超过98．6％。遗传多样性分析表明,橡胶树种质间遗传距离为0．25－0．81,RRIM600种质内遗传距离为0．07－0．17。通过基因分型分析获得一条大小为320bp的抗白粉病种质特有的片段。根据以上的AFLP数据进行了聚类分析,结果表明所有被研究种质几乎是依次聚成一个大类。     

AFLP Fingerprinting Analysis of Elite Hevea brasiliensis Germplasm

There are more than 6 000 clones of Hevea brasiliensis Mull. Ary germplasm in the germplasm garden of Chinese National Key Biotechnology Laboratory for Tropical Crops and some of them are elite germplasm demonstrated by production and previous studies. AFLP (amplified fragment length polymorphism) fingerprinting analysis was performed on 25 clones (15 of Wickham clones and 10 of Amazon wild clones which possess phenotypes with high-yielding/low-yielding, cold-tolerance/cold-sensitivity, oidium-resistance/oidium-sensitivity, tapping panel dryness (TPD)/healthy) respectively through a 377 DNA sequencer (P. E. Corp.) and PAGE electrophoresis results were analyzed by using GeneScanTMand GenotypeTM Analysis software (P.E.Corp.). The fragment profiles of different clones were obtained. Five hundred and eighteen fragments were generated by two primer combinations screened from 64 primer combinations and 511 fragments appeared to be polymorphic (98.6%). Genetic distance ranged from 0.25 to 0.81 between clones and ranged from 0.07 to 0.17 within RRIM600 clone. A specific 320 bp fragment of the oidium-resistant clones was found through genotype analysis. These results showed that AFLP fingerprints were highly reproducible and powerful and can be widely used in germplasm identification and genetic diversity analysis of Hevea brasiliensis. In addition, based on the AFLP data, cluster analysis was performed. Cluster results showed that all the clones studied were almost clustered into a group one by one.      

Chromosomal location of AFLP markers in common wheat utilizing nulli-tetrasomic stocks.

Amplified fragment length polymorphism (AFLP) markers with a total of 256 EcoRI + ANN - MseI + CNN primer combinations were investigated employing the common wheat cultivar Triticum aestivum 'Chinese Spring.' On average, 103 fragments per primer combination were amplified, ranging from a maximum of 226 fragments to a minimum of 18 fragments. The primer combinations E + AAA - M + CNN and E + ATT - M + CNN produced very few distinct fragments. By using 15 randomly chosen EcoRI + ANN - MseI + CNN primer combinations, 928 AFLP markers were allocated to wheat chromosomes, of which 131 were assigned to specific chromosome arms. These AFLP markers were locus-specific and randomly distributed on the different chromosomes. In addition, 6 and 41 AFLP markers were simultaneously absent in two nulli-tetrasomics (NTs) of both homoeologous and non-homoeologous groups, respectively, whereas additional fragments were detected in N1BT1A, N5AT5D, and N6BT6A lines.     

Assessment and comparison of AFLP and SSR based molecular genetic diversity in Indian isolates of Ascochyta rabiei, a causal agent of Ascochyta blight in chickpea (Cicer arietinum L.)

Ascochyta blight (AB), caused by Ascochyta rabiei (Pass.) Labr. (anamorph), is the most damaging disease of chickpea (Cicer arietinum L.) and is a serious biotic stress constraint for chickpea production. To understand the molecular diversity in A. rabiei populations of India, a total of 64 isolates collected from AB-infected chickpea plants from different agroclimatic regions in the North Western Plain Zone (NWPZ) of India were analyzed with 11 AFLP (amplified fragment length polymorphism) and 20 SSR (simple sequence repeat) markers. A total of 9 polymorphic AFLP primer pairs provided a total of 317 fragments, of which 130 were polymorphic and showed an average PIC value 0.28. Of the SSR markers, 12 showed polymorphism and provided a total of 29 alleles with an average PIC value 0.35. To the best of our knowledge, this is the first report on a comparison of AFLP and SSR diversity estimates in A. rabiei populations. The dendrogram developed based on AFLP and SSR data separately, as well as on the combined marker dataset, grouped the majority of AB isolates as per geographic regions. Model based population structure analysis revealed four distinct populations with varying levels of ancestral admixtures among 64 isolates studied. Interestingly, several AFLP primer combinations and SSR markers showed the locus/allele specific to AB isolates of certain regions, e.g., Hisar, Sriganganagar, Gurdaspur, and Sundarnagar. Genetic variability present in AB isolates of the NWPZ of India suggests the continuous monitoring of changes in A. rabiei population to anticipate the breakdown of AB resistance in chickpea cultivars grown in India.