用RAPD分析多年生黑麦草品种间遗传多样性

多年生黑麦草是世界上应用最广泛的冷季型草坪草兼牧草之一,具有建植快速,分蘖能力强,适口性良好等特点。为了评价其品种间的遗传多样性,选取了多年生黑麦草的14个草坪型品种和2个意大利黑麦草品种用RAPD进行遗传多样性分析,并且对每个品种的几项坪用特性进行了观察。61个引物共扩增出408条带,多态条带比率(PPB)为89．95％。聚类分析结果表明,多年生黑麦草品种之间的遗传多样性较低,相似系数分布于44．55％～95．69％之间。一年生黑麦草的2个品种TopOne和A,vance没有单独聚成一类,而是与14个多年生黑麦草品种混合聚在一起,而且Avance与其他多年生黑麦草之间的相似系数较高。聚类结果与形态特征没有明确的对应关系。     

基于SSR标记的草莓品种亲缘关系分析

摘要：用18对SSR引物对96份草莓栽培品种资源进行扩增。在18个SSR位点共获得184个条带,其中多态性条带为172个,多态性条带比率为93.5％,不同引物扩增的多态性条带数为6～19个,平均为9.56个。各位点PIC值在0.5726～0.8885之间,平均0.8057。NTSYS软件进行相似性系数计算,UPGMA法进行聚类分析结果显示,96份来源不同的草莓品种被混杂地聚在一起,草莓品种的亲缘关系与其来源并不存在明显的相关性,中国地方品种的聚类相对集中,中国地方品种与中国选育品种之间亲缘关系相对较远。欧美品种和日本品种的遗传基础要宽于中国选育品种和地方品种。     

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0.26kb-1.98kb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100bp-500bp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0．6495,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0．6884。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。     

甘薯品种的SRAP遗传多样性分析

利用分子标记SRAP技术,对36个甘薯品种进行了DNA多态性分析。选取6对引物扩增甘薯基因组DNA,共获得112条带,其中110条为多态性条带,平均每对引物提供18个标记信息。由UPMGA方法得到的聚类分析结果表明了36个品种间的遗传关系。相似系数在0.62~0.92之间,品种间有较高的遗传相似性;在聚类树中,亚洲品种和美洲品种之间没有明显的遗传分化,表明甘薯品种间没有明显的地理差异;近缘野生种与育成品种聚在一起,没有明显的遗传分化,这意味着它们之间有较高的遗传相似度;中国育成品种聚在一起,表明它们之间的遗传相似度很高。     

草坪蒸散研究进展

草坪蒸散量是指导草坪合理灌溉的重要指标。自20世纪中叶以来,以节水为目的的草坪蒸散研究越来越受到人们的重视。草坪蒸散研究的内容主要包括相互关联的3个方面：草坪蒸散率的测定与比较,草坪蒸散机制的研究和草坪节水灌溉的研究。草坪蒸散率在不同草种间存在不同程度的差异。暖季型草坪草和冷季型草坪草相比普遍具有较低的草坪蒸散率。暖季型草坪草的夏季日平均最大蒸散率为3.0-9.0mm,而冷季型草坪草的为3.6-12.6mm。密度大,生长缓慢的杂交狗牙根、结缕草、野牛草和假俭草的耗水量很低,细羊茅的耗水量中等,而草地早熟禾、高羊茅、1年生早熟禾和匍匐剪股颖的耗水量很大。同种草坪草的不同品种的草坪蒸散率存在差异。有些草种内品种间差异的程度高达64％,不亚于种间。冷季型草坪草品种的蒸散率与留茬量显著相关,但环境因子对品种的蒸散率影响很大,品种的蒸散特性不稳定。与冷季型草坪草相比,暖季型草坪草的种内品种间蒸散率的差异和谐较小。草坪的冠层是草坪蒸散的一个主要外部条件,具有较低蒸散率的草坪往往具备高冠层阻力和低叶面积。土壤水分不受限制时,不同的暖季型草坪草种间的草坪蒸散率与叶片背面的气孔密度显著负相关。但在种内品种间没有表现出相关性。冷季型草坪草种间和种内的叶片气孔数目和草坪的蒸散率不相关。草坪的作物系数是确定最适灌溉量的关键参数,线性梯度灌溉系统比小型蒸渗仪提供的草坪作物系数更接近于实际。当草坪的质量维持在可接受的水平时,以彭曼公式推测的苜蓿的潜在蒸散量为参照蒸散量,高羊茅草坪的作物系数为0.60-0.80,草地早熟禾草坪的作物系数为0.50-0.80。基于草坪冠层温度的作物水分胁迫系数（CWSI）是确定灌溉时机的比较合理的指标。CWSI在不同的季节和不同的草种间表现不稳定,并且这种方法的节水效果也表现不一,还处于发展阶段。草坪蒸散的研究在我国几乎处于空白状态,开展我国的草坪蒸散研究,寻求适合的草坪节水途径已势在必行。     

14个蝴蝶兰品种遗传关系的ISSR分析

采用ISSR分子标记技术对14个蝴蝶兰品种进行品种间遗传关系的研究。利用14个筛选的引物共扩增出179条带,其中多态性条带147条,多态性条带比率（PPB）为82％。品种之间的遗传相似系数范围在0．734—0．936间,说明部分蝴蝶兰品种间存在显著的遗传分化。14个引物组合可区分所有14个品种,并且检测到20条品种特异性条带,这些品种特异条带可用来鉴定供试蝴蝶兰中的10个品种。因此,ISSR分子标记能有效地进行蝴蝶兰品种鉴定。UPGMA聚类分析表明,14个品种可聚为2类,聚类情况与花色特征比较一致,但与花色的划分结果不完全相同,这可能是由于品种间杂交引起的。本文也论讨了ISSR分析结果对蝴蝶兰育种的指导意义。     

30个枣树种质资源遗传多样性的ISSR分析

取30个枣树品种进行ISSR分子标记分析,其扩增条带分别进行琼脂糖和聚丙烯酰胺凝胶电泳检测,以期获得不同产地品种之间的遗传多态性。从100条选择扩增的ISSR引物中筛选出17条扩增清晰、重复性和稳定性好的引物,选取其中8条扩增条带多态性强的引物进行遗传聚类分析。结果表明：（1）1％琼脂糖凝胶电泳和5％聚丙烯酰胺凝胶电泳检测扩增总条带数分别为72和127条,其中多态性条带分别为51条和113条,多态性条带比率（PPB）分别为70．8％和88．9％。（2）基于UPGMA软件对30个品种的遗传差异性分析表明,8个ISSR引物可以将枣树品种之间遗传差异明显区分开来。两种电泳检测方法相比较,聚丙烯酰胺凝胶电泳检测可获得较为精细的枣树品种间遗传图谱。其遗传相似系数范围在0．56～1．00之间,以0．62为最低遗传相似系数,可将30个枣树品种分成3个大类,6个亚类,为进一步研究枣树品种间分类、起源进化关系和分子辅助育种奠定基础。     

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.     

海带种质资源遗传多样性的RAPD分析

利用RAPD分子标记技术对种质库中保存的19个海带品种(系)的36个海带配子体进行了遗传多样性分析。从100条引物中筛选出16条可扩增出清晰条带的引物,在36个海带配子体中共扩增出362条DNA条带,其中多态性条带比例达99.45%。遗传相似性分析表明,这36个配子体之间的遗传相似性范围为0.682-0.978,以0.756为最低遗传相似系数,可将36个种质材料分为6个大类,UPGMA聚类分析结果表明同一品系的雌雄配子体大部分能聚在一起,品系间遗传多样性较高。     

红掌品种亲缘关系SRAP分析

利用相关序列扩增多态性（SRAP）分子标记,从100对引物组合中筛选出 26对多态性高、条带清晰的SRAP引物,对33个红掌品种进行遗传多样性和亲缘关系分析。结果如下：（1）26对引物共扩增出366条条带,其中有314条多态性条带,多态性比率为85.79%。引物组合产生的条带数在9～23之间,平均每对引物组合扩增出14.1条和12.1条多态性条带。（2）根据SRAP扩增结果,利用UPGMA法进行聚类分析,33份材料的遗传相似系数在0.55～0.94之间,在遗传相似系数0.786处可将33个红掌品种分为5个类群。结果表明,供试品种遗传多样性丰富,本研究为品种鉴定和杂交育种提供了参考信息。     

Inheritance of parental genomes in progenies of Poa pratensis L. from sexual and apomictic genotypes as assessed by RAPD markers and flow cytometry

 Moving gene(s) responsible for the apomictic trait into crop plants that naturally reproduce through a sexual process would open up new areas in plant breeding and agricultural systems. Kentucky bluegrass (Poa pratensis L.) is one of the most important forage and turf grasses in temperate climates. It reproduces through facultative aposporous parthenogenesis, but the reproductive behaviour ranges naturally from nearly obligate apomixis to complete sexuality. In addition to apomictic reproduction, sexual hybridization may take place. Selfing may also occur, and occasionally reduced egg cells may develop through parthenogenesis generating (poly)haploids. The inheritance of parental genomes was assessed in Kentucky bluegrass progenies by employing RAPD markers in combination with flow cytometry (FCM). Nine progenies from different crosses carried out between completely sexual and highly apomictic genotypes were evaluated in order to probe the reproductive behaviour of the mother plants and to distinguish the different classes of aberrant plants. Not only were maternals and balanced B_II hybrids recorded, but so were (poly)triploid B_III hybrids, selfs, and (poly)haploids. The application of these techniques demonstrated that FCM analysis accurately distinguishes the n, 2n, and 3n ploidy levels of progenies, and that RAPD markers unequivocally recognize progenies of apomictic and hybrid origin. The occurrence of aneusomaty was documented in one of the selected sexual genotypes, whose crossed progeny plants manifested two distinct classes of ploidy. The nomenclature B_I was adopted to refer to hybrids with a hypodiploid nuclear condition. On the whole, the FCM analysis confirmed most of the RAPD data. The combined evaluation of DNA markers and DNA contents proved to be an efficient screening tool for scoring maternal plants, assessing the genetic origin of aberrant plants, and quantifying the inheritance of parental genomes in Kentucky bluegrass. Hybrid populations from sexual×apomictic matings that segregate for the mode of reproduction represent a valuable basis for attempting to identify molecular markers linked to the apomixis gene(s). Received: 11 November 1996/Accepted: 22 November 1996     

Assessment of genetic variation withinBrassica campestris cultivars using amplified fragment length polymorphism and random amplification of polymorphic DNA markers

Genetic relationships were evaluated among nine cultivars ofBrassica campestris by employing random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers. RAPDs generated a total of 125 bands using 13 decamer primers (an average of 9.6 bands per assay) of which nearly 80% were polymorphic. The per cent polymorphism ranged from 60–100%. AFLP, on the other hand generated a total of 319 markers, an average of 64 bands per assay. Of these, 213 were polymorphic in nature (66.8%). AFLP methodology detected polymorphism more efficiently than RAPD approach due to a greater number of loci assayed per reaction. Cultivar-specific bands were identified, for some cultivars using RAPD, and for most cultivars with AFLP. Genetic similarity matrix, based on Jaccard’s index detected coefficients ranging from 0.42 to 0.73 for RAPD, and from 0.48 to 0.925 for AFLPs indicating a wide genetic base. Cluster analyses using data generated by both RAPD and AFLP markers, clearly separated the yellow seeded, self-compatible cultivars from the brown seeded, self-incompatible cultivars although AFLP markers were able to group the cultivars more accurately. The higher genetic variation detected by AFLP in comparison to RAPD was also reflected in the topography of the phenetic dendrograms obtained. These results have been discussed in light of other studies and the relative efficiency of the marker systems for germplasm evaluation.     

Optimization of in vitro multiple shoot clump induction and plantlet regeneration of Kentucky bluegrass (Poa pratensis)

An efficient protocol for Kentucky bluegrass (Poa pratensis L.) in vitro culture was established using shoot apices of seedlings as explants. The optimal procedure of this protocol for majority of the genotypes was that meristematic cell clumps and small calluses were firstly induced from the bases of explants on initial culture medium supplemented with 0.9 μM 2,4-d and 8.9 μM 6-BA for 20 d, then were separated and transferred to shoot clumps induction medium containing 8.9 μM 6-BA for the formation of multiple shoot clumps. The percentage of multiple shoot clumps and numbers of shoots per clump were deeply related with the combinations of different plant growth regulators, duration of initial culture, the intensity of illumination and genotypes. Histological observation of the induced explants revealed that the meristematic cell clumps were produced from repeated division of the cortical cells and original meristematic primodium cells of explants, and the multiple shoots were formed via organogenesis pathway in the meristematic cell regions of cultures on shoot clumps induction medium. In this study, plantlets were efficiently regenerated on large scale from seven cultivars of Kentucky bluegrass. Hence the meristematic cell clumps and small calluses in this protocol could be considered good targets for genetic transformation of Kentucky bluegrass.     

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。     

Inheritance of parthenogenesis in Poa pratensis L.: auxin test and AFLP linkage analyses support monogenic control

 Gametophytic apomixis in Kentucky bluegrass (Poa pratensis L.) involves the parthenogenetic development of unreduced eggs from aposporic embryo sacs. Attempts to transfer the apomictic trait beyond natural sexual barriers require further elucidation of its inheritance. Controlled crosses were made between sexual clones and apomictic genotypes, and the parthenogenetic capacity of (poly)diploid hybrids was ascertained by the auxin test. A bulked segregant analysis with RAPD and AFLP markers was then used to identify a genetic linkage group related to the apomictic mode of reproduction. This approach enabled us to detect both an AFLP marker located 6.6 cM from the gene that putatively controls parthenogenesis and a 15.4-cM genomic window surrounding the target locus. A map of the P. pratensis chromosome region carrying the gene of interest was constructed using additional RAPD and AFLP markers that co-segregated with the parthenogenesis locus. Highly significant linkage between parthenogenesis and a number of AFLP markers that also appeared to belong to a tight linkage block strengthens the hypothesis of monogenic inheritance of this trait. If a single gene is assumed, apomictic polyploid types of P. pratensis would be simplex for a dominant allele that confers parthenogenesis, and this genetic model would be further supported by the bimodal distribution of the degree of parthenogenesis exhibited in the (poly)diploid progenies from sexual x apomictic matings. The molecular tagging of apomixis in P. pratensis is an essential step towards marker-assisted breeding and map-based cloning strategies aimed at investigating and manipulating its mode of reproduction. Received: 13 January 1998 / Accepted: 19 January 1998     

RAPD Profile Analysis of Betel Vine Cultivars

RAPD analysis in selected cultivars of Kapoori and Bangla betel vines (Piper betle L.) were carried out in order to ascertain the relatedness of the two to each other. On the basis of the data from 10 RAPD primers, it was found that the Kapoori cultivars were more heterogeneous (mean SI = 0.521) while the Bangla cultivars were mostly similar to each other (mean SI = 0.884). Within each type, the overall polymorphism of RAPD bands was more than 70 %. When RAPD band data for both types of cultivars were considered cumulatively, the two were clearly separated from each other. In fact only six bands out of a total of 60 bands were found to be common to cultivars of both types. Bands specific to only one of the two types have potential for developing betel vine cultivar-specific probes and SCAR-markers.     

从进口早熟禾种子中检出的一种腥黑粉菌与其近似种的比较

早熟禾是优良的草坪草和牧草,近年来,天津出入境检验检疫局多次从进境的草地早熟禾、加拿大早熟禾及一年生早熟禾上截获一种腥黑粉菌,暂名为Tilletia sp.。针对T. sp.、早熟禾上的形态相近的T. sterilis、T. togwateei,以及同属近似种雀麦腥黑粉菌T. bromi和禾草腥黑粉菌T. fusca在冬孢子形态特征、萌发特性及细胞学性状等方面进行了系统比较。结果表明,Tilletia sp.与T. sterilis、T. togwateei存在较大差异,与T. bromi和T. fusca差别不明显;截获菌与Tilletia sp.在菌瘿、冬孢子形态特征上与T. bromi更为接近,根据研究结果将Tilletia sp.定名为T. bromi。     

Assessment of genetic variation within Indian mustard (Brassica juncea) germplasm using random amplified polymorphic DNA markers

Genetic diversity among 45 Indian mustard (Brassica Juncea L.) genotypes comprising 37 germplasm collections, five advance breeding lines and three improved cultivars was investigated at the DNA level using the random amplified polymorphic DNA (RAPD) technique. Fifteen primers used generated a total of 92 RAPD fragments, of which 81 (88%) were polymorphic. Of these, 13 were unique to accession 'Pak85559'. Each primer produced four to nine amplified products with an average of 6.13 bands per primer. Based on pairwise comparisons of RAPD amplification products, Nei and Li's similarity coefficients were calculated to evaluate the relationships among the accessions. Pairwise similarity indices were higher among the oilseed accessions and cultivars showing narrow ranges of 0.77-0.99. An unweighted pair-group method with arithmetic averages cluster analysis based on these genetic similarities placed most of the collections and oilseed cultivars close to each other, showing a low level of polymorphism between the accessions used. However, the clusters formed by oilseed collections and cultivars were comparatively distinct from that of advanced breeding lines. Genetically, all of the accessions were classified into a few major groups and a number of individual accessions. Advanced breeding lines were relatively divergent from the rest of the accessions and formed independent clusters. Clustering of the accessions did not show any pattern of association between the RAPD markers and the collection sites. A low level of genetic variability of oilseed mustard was attributed to the selection for similar traits and horticultural uses. Perhaps close parentage of these accessions further contributed towards their little diversity. The study demonstrated that RAPD is a simple and fast technique to compare the genetic relationship and pattern of variation among the gene pool of this crop.