优良草坪新品种在昆明地区的引种适应性评价

对47个冷季型草种在昆明地区进行了引种适应性评价.结果如下:(1)5个草坪草从播种到出苗所需时间不同,多年生黑麦草出苗最快,高羊茅次之,剪股颖、早熟禾最慢.同一草坪草在幼苗期和成坪后生长速度不同,不同草坪草在幼苗期或成坪后生长速度也不同,高羊茅、黑麦草的草坪自然高度都相对较高,各个草坪草品种间存在差异.(2)早熟禾、匍匐剪股颖的叶片质地最细,其次为多年生黑麦草,高羊茅最粗糙.草坪各个品种之间的密度存在差异,表现较好的有火龙、21世界、优美、碧盛、高地和太阳城.(3)早熟禾、剪股颖盖度较黑麦草、高羊茅要好.(4)黑麦草的再生性最好、高羊茅次之,剪股颖、旱熟禾最慢.(5)黑麦草、高羊茅叶绿素含量较高,与外观表现一致,各个草坪草品种的均一性之间差异显著.     

高羊茅杂交后代ISSR遗传变异研究

利用ISSR分子标记对高羊茅(Festuca arundinacea)杂交后代进行遗传多样性及亲缘关系分析.19个ISSR引物共扩增出255条重复性好、清晰的条带,其中200条是多态条带,多态条带比率(PPL)为78.4％,平均每个引物扩增多态条带数为10.5条,扩增片段大小范围为100～2 000 bp.结果表明,高羊茅杂交后代的多态性较高,遗传多样性较丰富.高羊茅杂交后代遗传相似性系数为0.647 1～0.851 0,聚类分析将高羊茅杂交后代划分为4个大类,有相同亲本的杂交后代先聚类.总之,ISSR标记可以有效地对高羊茅杂交后代进行“亲缘跟踪”和定向选择,为杂交育种提供分子依据.     

西瓜种质资源遗传多样性的SRAP分析

【研究目的】研究西瓜材料之间的亲缘关系及其分类,为进一步利用和创新材料、培育新的品种提供依据;【方法】采用SRAP技术对64份西瓜种质资源的遗传多样性进行了研究;【结果】从700多个引物组合中筛选出了51个条带清晰、多态性高的引物组合来分析供试材料,共产生431条扩增带,其中243条带具有多态性,多态性频率平均为56.4%,除去非洲野生型57号材料,其它材料间多态率为39.4%。将243条多态性SRAP条带,利用NTSYS软件计算了64个材料间的遗传相似系数,其变化范围为0.47~0.97,除非洲野生型材料57号等4个差异较大的材料,其它材料间变化范围仅为0.87~0.97;【结论】说明目前西瓜育种的大多数材料间同源性较高,遗传分化较小,其遗传基础非常狭窄。该研究结果对利用特殊种质、合理选择杂交亲本具有一定的参考价值。     

利用酶分解法评价牧草的可消化性

采用酶分解法分析测定禾本科2个草种8个品种不同刈割时期的细胞组成成分含量，通过公式推算出于物质消化率和可消化养分总量，评价牧草品质。结果表明，意大利黑麦草各品种间可消化性无显著差异，但高Mg的Magnet于物质消化率显著高于Tachiwase。高羊茅的高Mg品种Himag可消化性显著高于其他3个品种，而其他3个品种之间无显著差异。2个草种在10月份的可消化性高于其他刈割时期，意大利黑麦草7月的可消化性最低，高羊茅9月的可消化性最低。     

利用RAPD、ISSR标记分析白芨种质资源遗传多样性的研究

旨在分析不同地区野生驯化白芨居群间亲缘关系,为白芨资源保护和利用提供支撑。利用RAPD和ISSR标记技术从分子层面鉴别源于湖南、湖北、贵州、云南、江西等地的12个白芨资源遗传多样性差异,并通过UPGMA对该差异性进行了聚类分析。结果表明,在36条供试RAPD引物中有13条扩增带型清晰、多态性高,15条供试ISSR引物中有2条扩增带型清晰、多态性高,共获得40条多态性条带;通过UPGMA聚类分析表明,12份供试白芨种质资源间具有较高的遗传多样性,遗传距离最大可达0.975,供试材料总体上可分为两个支系,湖南、江西为一个支系,湖北、贵州和云南为一个支系。利用ISSR和RAPD标记可以从分子水平上揭示白芨的种质资源遗传多样性,同时,研究还发现ISSR标记能比RAPD标记扩增出更多的多态条带和获得更高的多态比率,且分析不受时间和地点限制,结果更稳定、可靠。本研究结果显示白芨居群间遗传差异性与地理距离呈现一定的相关性,对研究白芨物种的演化及遗传多样性提供了相关数据和理论支持。     

PEG胁迫对冷季型草坪草种子萌发和幼苗生长的影响

本试验采用不同浓度聚乙二醇(PEG-6000)溶液,对多年生黑麦草、高羊茅和草地早熟禾种子的萌发情况进行了研究.结果表明,在干旱胁迫下多年生黑麦草和草地早熟禾均推迟了萌发时间且随浓度不断增大推迟时间延长,但对高羊茅影响不大.低浓度(5％)PEG对多年生黑麦草和草地早熟禾种子发芽有一定促进作用,高浓度( 15％ ～ 25％)对3种植物种子的萌发都表现为抑制作用.3种草坪草种子的抗旱性顺序为高羊茅＞多年生黑麦草＞草地早熟禾.     

污泥浸提液与稀土镧浸种对草坪草种子萌发及初期生长的影响

以污泥浸提液中添加不同浓度的稀土镧对黑麦草和高羊茅浸种,研究了污泥浸提液和稀土镧对2种草坪草种子萌发及其初期生长的影响.结果表明,污泥浸提液与不同浓度稀土镧混合浸种对黑麦草和高羊茅的萌发和初期生长均有促进作用.从种子萌发来看,200 mg/L镧+污泥浸提液处理下,黑麦草种子活力指数最高,较对照增加了71.4％,而高羊茅在100 mg/L镧+污泥浸提液处理下最高.稀土镧+污泥浸提液处理能显著促进2种草坪草幼苗株高生长,与对照相比,200 mg/L镧+污泥浸提液处理在播种后第5天黑麦草和高羊茅的株高分别增加了33.4％和24.7％.黑麦草和高羊茅的地上干重分别在300 mg/L镧+污泥浸提液处理和200 mg/L镧+污泥浸提液处理下达到最大.从叶绿素含量来看,300 mg/L镧+污泥浸提液处理下最高,黑麦草的叶绿素a和总叶绿素含量分别高出对照20.6％和18.4％,而高羊茅分别比对照高43.7％和34.4％.     

块根淀粉磷差异木薯种质资源的RAPD遗传背景研究

通过RAPD遗传背景研究方法,从分子水平对木薯块根淀粉磷差异种质资源进行分析,为木薯块根淀粉高磷品种的选育打下基础。以国家木薯种质圃筛选出的30个块根淀粉磷差异木薯品种为材料,采用改良CTAB法提取DNA,通过18条RAPD引物对材料进行PCR扩增,利用NTSYS软件对扩增结果进行了遗传关系分析。结果表明：采用改良的CTAB法提取的DNA可以用于RAPD分析;利用18条RAPD引物扩增共得出条带131条,其中多态性条带126条,多态性百分率为96.2%;其中没有发现与磷含量相关的特异性条带,块根淀粉磷含量相近的木薯品种间不能明显聚类;30个品种间的遗传相似性系数GS大于0.71。通过对RAPD结果进行分析,未发现块根淀粉磷含量差异的木薯品种间存在明显的遗传关系,也未发现与磷元素差异相关的特异基因。     

应用RAPD标记检测小豆种质资源的遗传多样性初探

检测野生型、半野生型及栽培型小豆种质资源的遗传多样性,对进一步探讨小豆的起源地、品种分化和传播途径具有极其重要的价值。本研究用RAPD标记方法对来自中国、日本、韩国、不丹、尼泊尔、越南等6国99份小豆种质资源DNA的遗传多样性进行了检测。7个引物共检测到102条带,具有多态性的谱带100条,其中7条带仅存在于单个材料     

3种混播草坪外观质量比较研究

为确定昆明地区混播绿地草坪的适宜组合,本研究采用“NTEP九分制”法对昆明地区3组（组合1：70%高羊茅+20%草地早熟禾+10%多年生黑麦草;组合2：50%高羊茅+40%草地早熟禾+10%多年生黑麦草;组合3：30%高羊茅+60%草地早熟禾+10%多年生黑麦草）混播绿地草坪进行外观质量评价。结果表明组合3草坪得分最高(6.97),综合分析认为以草地早熟禾为建群种,高羊茅为伴生种,多年生黑麦草为先锋草种的混播搭配所建植的绿地草坪质量较好,适宜在昆明地区建坪使用。     

A comparative analysis of the genetic relationships between rye cultivars using RFLP and RAPD markers

Summary The genetic similarities of eight closely related rye cultivars were estimated using two molecular marking techniques: restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD). Cultivars were evaluated for variation by 11 random cDNA and genomic clones used in combination with four restriction enzymes and 40 decamer primers. A total of 53 polymorphic RFLP fragments and 94 polymorphic RAPD fragments were observed. Based on the presence/absence of fragments, two genetic similarity matrices were calculated which were then used in cluster analysis. Differences between pair of cultivars were observed in RFLP and RAPD dendrograms. RFLP analysis produced estimates of genetic relationships more in accordance with the partially known pedigree of the cultivars than did RAPD analysis. The use of bulk samples of DNA in these analyses affected the sensitivity of RAPD assays more strongly. Dendrograms which took into account all fragments produced, either by RFLP or RAPD, reflected better the relationships between cultivars than did dendrograms based on only one type of marker. This reflects the importance of the number of markers used in determining the genetic relationships between genotypes.     

Evaluation of random amplified polymorphic DNA (RAPD) markers in Hevea brasiliensis

The applicability of random amplified polymorphic DNA (RAPD) markers in the cultivated rubber tree, Hevea, was evaluated using 43 decamer oligonucleotide primers in a set of 24 clones selected in different South-East Asian countries. A total of 220 0.35–3.5 kb DNA fragments were amplified, of which 111 were polymorphic. Of these, 80 fragments (RAPD markers) which were repeatable and clearly scorable across all genotypes were used to estimate genetic distances among the clones tested. The estimated genetic distances ranged from 0.05 (RRII 308 and PB 5/51) to 0.75 (RRIC 100 and SCATC 88–13). A mean genetic distance of 0.5 indicates a rather high genetic variability among the tested clones. As expected, because of the breeding history of Hevea, UPGMA cluster analysis and Principal Coordinate Analysis (PCoA) indicated the absence of a distinct geographical grouping. The possible application of RAPD markers for clone identification and also for analysis of genetic relationships among Hevea clones is discussed.     

利用RAPD标记研究燕麦属不同种的遗传差异

利用RAPD标记对我国8个燕麦种共21份材料的遗传差异及类群划分进行了研究。22个多态性引物在21个基因型间共扩增出114条带，其中97条带具有多态性，占85．1％。用这些条带计算了不同基因型间的遗传距离，发现各种间的遗传距离(0．053～0．510)普遍大于不同种内的遗传距离(0．022～0．087)。聚类结果显示，21份材料可划归为5大类群8个亚群，并与传统的分类结果基本一致。由此表明，用RAPD标记对燕麦进行遗传关系和分类研究是可行的。     

Appraisal of RAPD and ISSR markers for genetic diversity analysis among cowpea (Vigna unguiculata L.) genotypes

The genetic variability and relationships among 11 cowpea genotypes representing two cultivars and nine elite genotypes were analyzed using 22 random amplified polymorphic DNA (RAPD) and nine inter-simple sequence repeat (ISSR) markers. ISSR markers were more efficient than RAPD assay with regards to polymorphism detection. But the average numbers of polymorphic loci per primer and resolution power were found to be higher for RAPD than for ISSR. Also, the total number of genotype specific marker loci, Nei’s genetic diversity, Shannon’s information index, total heterozygosity, and average heterozygosity were prominent in RAPD as compared to ISSR markers. The regression test between the two Nei’s genetic diversity indices showed low regression (0.3733) between ISSR and RAPD + ISSR-based similarities but maximum (0.9823) for RAPD and RAPD + ISSR-based similarities. The RAPD- and ISSR-generated cultivar- or genotype-specific unique DNA fingerprints able to identify the most diverse genotypes. A dendrogram constructed based on RAPD and ISSR combined data indicated a very clear pattern of clustering according to the groups (cultivars and elite genotypes). The results of principal coordinate analysis were comparable to the cluster analysis. Cluster analysis showed that most diverse genotypes (GP-125 — small size with good seed quality; GP-129, GP-90L — big size with poor seed quality) were separated from moderately diverse cultivars and genotypes. The genetic closeness among GP-129 and GP-90L, JCPL-42, and JCPL-107 could be explained by the high degree of commonness in these genotypes.     

Characterization and genetic distance analysis of cassava (Manihot esculenta Crantz) germplasm from Mozambique using RAPD fingerprinting

Twenty-eight cassava genotypes from Mozambique, along with seven genotypes from Angola, Madagascar, Nigeria, Togo, Columbia, and Thailand for comparison, were fingerprinted using random amplified polymorphic DNA (RAPD) analysis. The Mozambican material represented a wide range of landraces. A total of 311 scored RAPD loci were used to calculate genetic distances between the genotypes. This revealed an average genetic distance of 3.1% between all the germplasm. The average genetic distance between the Mozambiquen genotypes was 2.7%, whilst the seven accessions from the other countries showed an average distance of 3.4%. Neighbor-joining (NJ) method cluster analysis of the genetic distance yielded a tree that did not indicate a relationship between geographic distribution and genetic diversity. This revised version was published online in August 2006 with corrections to the Cover Date.     

DNA fingerprinting studies in coloured cotton genotypes

A collection of 11 coloured cotton Gossypium hirsutum genotypes and four white linted genotypes of different origin were evaluated by randomly amplified polymorphic DNA (RAPD) analysis. These 15 cotton genotypes were evaluated using 32 different 10‐mer primers of arbitrary sequences. All 32 primers were polymorphic ‐ in total, 287 amplified fragments were observed in these patterns. Out of the 287 fragments, 219 were polymorphic accounting for 76.31% of the total number of fragments. Similarity indices were calculated using the Dice coefficient and a dendrogram showing relationships between genotypes was obtained by Unweighted Pair Group Method of Arithmetic Average (UPGMA) cluster analysis. Cluster analysis showed clear‐cut separation of the coloured and white linted genotypes and thus formed three clusters (I, II and III). Among the coloured linted genotypes, all except ‘Parbhani American’ and ‘Lousiana brown’ clustered together. Cluster II contained white linted genotypes orginating from the same breeding station. The results indicate that RAPDs may constitute a relatively simple and efficient method for analysing genetic variation in coloured and white linted G. hirsutum collections.     

Assessment of genetic diversity among wheat (Triticum aestivum L.) cultivars from a range of localities across Pakistan using random amplified polymorphic DNA (RAPD) analysis

Genetic diversity among 20 wheat genotypes/cultivars from diverse locations of Pakistan was studied using random amplified polymorphic DNA (RAPD) analysis. A total of 445 DNA fragments were amplified with50 random decamer primers 64.38% of which were polymorphic. Genetic similarity matrix based on Nei & Li's (1979) index detected coefficients ranging from 75.60% to 92.74%. These coefficients were used to construct a dendrogram using unweighted pair group of arithmetic means (UPGMA). The wheat genotypes were clustered into one major group (A) and two small groups (B and C). The most distant genotype in the dendrogram was PARC-1 that was 75.60% to 84.94% genetically similar with the other genotypes and clustered with PARC-3 which formed a group distantly related with the other clusters. Moreover, most of the wheat genotypes developed from the same breeding centre clustered in one group. It has been clearly shown that most of the cultivars except PARC-1possessed narrow genetic background. The information would be helpful for future genome mapping programs as well as for the application of intellectual breeder rights in the country. The study will also work as indicator for wheat breeders to evolve varieties with diverse genetic background to achieve sustainability in wheat production in the country. This revised version was published online in August 2006 with corrections to the Cover Date.     

Genetic Relationships in Malus Evaluated by RAPD 'Fingerprinting' of Cultivars and Wild Species

The potential use of RAPD markers for taxonomic studies in Malus was investigated using 18 accessions of wild species and 27 apple cultivars. 29 preselected random decamer primers were applied to three sets of Malus genotypes. Random amplified polymorphic DNA (RAPD) ‘fingerprints’ were analysed for polymorphic amplification fragments, and coefficients estimating genetic similarity were calculated on the basis of about 50 polymorphic RAPD loci in each set of genotypes. Cluster analysis by an unweighted pair-group method with arithmetic averages (UPGMA) revealed that, in the cultivars, the molecular classification was in good agreement with the known lineage. A dendrogram generated for the wild species gave relationships that were, in principle, in accordance with the known phylogenetic information. Closely related species from section I were clearly distinguishable from those of sections III and IV. On the molecular level, a high degree of genetic diversity was found among both different apple cultivars and wild species of the genus Malus. The results gave additional evidence for the hypothesis that M. pumila and M. sylvestris were involved in the origin of the cultivated apples.     

The effect of the number of RAPD markers on the evaluation of genotypic distances in Vitis vinifera

The effect of the number of RAPD fragments on the estimation of genetic distances has been studied on 10 genotypes (Vitis vinifera) using 320 primers. A total number of 1683 scorable bands was obtained but only polymorphic bands (932) were considered in this work. The variation of the genetic distances, in relation to an increasing number of bands, was evaluated through a bootstrap sampling procedure. The mean coefficient of variation (CV) of the genetic distances decreased as the number of bands increased. A CV of 10% was obtained with about 100–150 bands while a CV of 5% with a large number of bands (400–500 and over). To reduce the cost and the time of the analyses, primers with different levels of polymorphism were compared. Genetic distance matrices, based on different numbers of bands and primer polymorphism, were highly correlated with the genetic distance matrix of the whole data set when they were determined with a large number of RAPD fragments, either from high or low polymorphic primers. The effect of the number of bands on the estimation of genetic distances was evaluated also through the variation of the pattern of aggregation among genotypes (cluster analysis). Stable clusterings were detected when a large number of polymorphic bands (400 and over) was used. Some rearrangements of the genotypes in the dendrograms was observed as the number of bands decreased; below 100–150 bands the clusterings were completely rearranged. This revised version was published online in July 2006 with corrections to the Cover Date.     

Analysis of molecular variance and population structure in southern Indian finger millet genotypes using three different molecular markers

The genetic relationship among 42 genotypes of finger millet collected from different geographical regions of southern India was investigated using random amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR), and simple sequence repeats (SSR) markers. Ten RAPD primers produced 111 polymorphic bands. Five ISSR primers produced a total of 61 bands. Of these, 23 bands were polymorphic. The RAPD and ISSR fingerprints revealed 71.3 and 37.4% polymorphic banding patterns, respectively. Thirty-six SSR primers yielded 83 scorable alleles in which 62 were found to be polymorphic. Out of 36 SSR primers used, 14 primers (46.6%) produced polymorphic bands. The SSR primer UGEP7 produced a maximum number of six alleles. Mean polymorphic information content (PIC) of RAPD, ISSR and SSR were 0.44, 0.28, and 0.14, respectively. Molecular variances among the population were 2, 11, and 1% for RAPD, ISSR, and SSR markers, respectively. SSR produced 99% molecular variance within individuals. RAPD and ISSR markers produced a low level of molecular variance within individuals. The STRUCTURE (model-based program) analysis revealed that the 42 finger millet genotypes could be divided into a maximum of four subpopulations. Based on the Bayesian statistics, each RAPD and SSR marker produced three subpopulations (K=3), while ISSR marker showed four subpopulations (K=4). This study revealed that RAPD and SSR markers could narrow down the analysis of population structure and it may form the basis for finger millet breeding and improvement programs in the future.