Polymorphic microsatellite DNA markers for a relictual angiosperm Cercidiphyllum japonicum Sieb. et Zucc. and their utility for Cercidiphyllum magnificum

The genus Cercidiphyllum is considered to be a primitive, relictual angiosperm, with two extant species occurring in limited areas of East Asia. We developed seven microsatellite markers for Cercidiphyllum japonicum, of which, five showed a clear, strong single band for each allele. The average number of alleles and observed heterozygosity were 26.2 and 0.82, respectively. Three pairs of polymerase chain reaction primers successfully amplified the DNA of the other species, Cercidiphyllum magnificum.     

濒危植物连香树种群结构与动态研究

以空间代替时间的方法调查了喇叭河自然保护区和宝兴县两个地区连香树种群的结构.绘制大小结构图,编制静态生命表,绘制存活曲线、消失率曲线和死亡率曲线,并进行种群动态谱分析.结果表明:两个地区连香树种群幼苗个体比例都比较大,但死亡率很高;存活曲线介于Deevey Ⅰ型和DeeveyⅡ型之间;消失率和死亡率曲线变化趋势一致;种群动态过程存在周期性,种群数量动态不仅受基波的影响,而且还显示出了小周期的波动.     

濒危连香树种群性比和雌雄株功能性状的差异

雌雄异株植物种群性比偏倚和性别间功能性状的差异可能对种群维持产生不利影响,目前的研究很少关注雌雄异株濒危植物的性别差异.本文调查了四川小寨子沟国家级自然保护区内天然连香树种群性比并比较其雌雄株之间的形态、光合能力、水分和养分利用效率差异.结果发现,连香树种群性比显著偏雌(F/M=1.97;x^2 =4.46,P=0.035),雌株的胸径、冠幅、最大光合速率、表观量子效率、最大羧化效率、比叶面积、叶氮含量及水分、氮和磷利用效率分别比雄株高44.50%、27.94%、20.11%、50%、21.14%、14.32%、14.86%、158.7%、19.74%和28.03%,而其气孔导度、胞间CO2浓度、蒸腾速率和光补偿点分别低20.83%、24.61%、56.11%和44.44%,表明该地连香树种群存在性别偏倚且性别间已呈现出性别二态性,这可能是其濒危的重要原因,建议在探讨其濒危机制中应该考虑性别的因素.     

连香树树皮化学成分的研究

从连香树（Cercidiphyllum japonicum Sieb. et Zucc.）树皮中分离到8个化合物。其中7个为黄酮醇,1个为酚酸类成分。经理化测定和波谱解析,分别鉴定为5,7-二羟基-3,8,4′-三甲氧基黄酮 (Ⅰ)、3,5,7-三羟基-8,4′-二甲氧基黄酮 (Ⅱ)、5,7,4′-三羟基-3,8-二甲氧基黄酮 (Ⅲ)、3,5,7,4′-四羟基-8-甲氧基黄酮 (Ⅳ)、3,5,7,4′-四羟基黄酮 (Ⅴ)、5,7-二羟基-8,4′-二甲氧基黄酮-3-O-葡萄糖甙 (Ⅶ)、5,7,4′-三羟基-8-甲氧基黄酮-3-O-葡萄糖甙 (Ⅷ)和没食子酸乙酯 (Ⅵ)。其中化合物Ⅶ为未见报道的新化合物。除化合物Ⅴ外,其余化合物均为首次从该属植物中分得。     

连香树树皮化学成分的研究

从连香树（CercidiphyllumjaponicumSieb.etZucc.）树皮中分离到8个化合物。其中7个为黄酮醇,l个为酚酸类成分。经理化测定和波谱解析,分别鉴定为：5,7-二羟基-3,8,4'-三甲氧基黄酮（Ⅰ）、3,5,7-三羟基-8,4'-二甲氧基黄酮（Ⅱ）、5,7,4'-三羟基-3,8-二甲氧基黄酮（Ⅲ）、3,5,7,4'-四羟基-8-甲氧基黄酮（Ⅳ）、3,5,7,4'-四羟基黄酮（Ⅴ）、5,7-二羟基-8,4'－二甲氧基黄酮-3-O-葡萄糖甙（Ⅶ）、5,7,4'-三羟基-8-甲氧基黄酮-3－O-葡萄糖甙（Ⅷ）和没食子酸乙酯（Ⅵ）。其中化合物Ⅶ为未见报道的新化合物。除化合物Ⅴ外,其余化合物均为首次从该属植物中分得。     

Cross-species utility of microsatellite markers in trichostrongyloid nematodes

The development of microsatellite markers for parasitic nematodes has been hampered by technical difficulties in isolation and PCR amplification. We have investigated the potential for circumventing these problems using microsatellites from 3 trichostrongyloid species on a panel of 7 species. Ten of the 22 PCR primer pairs tested amplified in species other than the target species, usually in closely related species, and 2 new variable loci were discovered in the sheep parasite Trichostrongylus vitrinus. This study provides evidence that cross-species testing of microsatellite primers can be an effective alternative to isolation de novo.     

Isolation and characterization of microsatellite markers in the rare clonal plant, Spiraea virginiana (Rosaceae)

? Premise of the study: Microsatellite markers were developed in Spiraea virginiana, a federally threatened native shrub found along stream banks, to identify clonal genotypes and measure population genetic variability. ? Methods and Results: Eleven primer sets were developed using a non-radioactive protocol. These revealed a moderate level of genetic variation, as indicated by the number of alleles per locus (range = 1-4) and an average observed heterozygosity of 0.595. Select loci also amplified successfully in the related species Spiraea japonica. ? Conclusion: Development of the markers described here is critical for the genetic identification of clonal plants as a first step in demographic analyses, and is necessary for the future conservation of this rare species. Amplification of the markers in S. japonica suggests their potential utility in research regarding this species.     

Effect of gene flow on spatial genetic structure in the riparian canopy tree Cercidiphyllum japonicum revealed by microsatellite analysis

Few studies have analyzed pollen and seed movements at local scale, and genetic differentiation among populations covering the geographic distribution range of a species. We carried out such a study on Cercidiphyllum japonicum; a dioecious broad-leaved tree of cool-temperate riparian forest in Japan. We made direct measurement of pollen and seed movements in a site, genetic structure at the local scale, and genetic differentiation between populations covering the Japanese Archipelago. Parentage analysis of seedlings within a 20-ha study site indicated that at least 28.8% of seedlings were fertilized by pollen from trees outside the study site. The average pollination distance within the study site was 129 m, with a maximum of 666 m. The genotypes of 30% of seedlings were incompatible with those of the nearest female tree, and the maximum seed dispersal distance within the study site was over 300 m. Thus, long-distance gene dispersal is common in this species. The correlation between genetic relatedness and spatial distance among adult trees within the population was not significant, indicating an absence of fine-scale genetic structure perhaps caused by high levels of pollen flow and overlapping seed shadows. Six populations sampled throughout the distribution of C. japonicum in Japan showed significant isolation-by-distance but low levels of genetic differentiation (F(ST) = 0.043), also indicating long-distance gene flow in C. japonicum. Long-distance gene flow had a strong influence on the genetic structure at different spatial scales, and contributes to the maintenance of genetic diversity in C. japonicum.     

New microsatellite markers for bananas (Musa spp)

Thirty-four microsatellite markers (SSRs) were identified in EST and BAC clones from Musa acuminata burmannicoides var. Calcutta 4 and validated in 22 Musa genotypes from the Banana Germplasm Bank of Embrapa-CNPMF, which includes wild and improved diploids. The number of alleles per locus ranged from 2 to 14. The markers were considered highly informative based on their polymorphism information content values; more than 50% were above 0.5. These SSRs will be useful for banana breeding programs, for studies of genetic diversity, germplasm characterization and selection, development of saturated genetic linkage maps, and marker assisted selection.     

Multiplexed microsatellite markers for the genetic analysis of Eucalyptus leucoxylon (Myrtaceae) and their utility for ecological and breeding studies in other eucalyptus species

Eucalyptus leucoxylon is a widespread woodland tree species found in southeastern Australia that has suffered from, and continues to be, threatened by the impacts of habitat clearance and degradation. Populations now consist predominantly of scattered individuals, and their conservation status is of increasing concern. We report the development and characterization of a set of eight highly polymorphic microsatellite loci for E. leucoxylon. The loci can be amplified in three PCR multiplexes and electrophoresed in a single lane, allowing rapid throughput of large numbers of samples. A total of 111 alleles were detected in 68 individuals with an average of 12.3 alleles per locus, a mean expected heterozygosity of 0.83, and a mean observed heterozygosity of 0.72. The combined probabilities of identity and probabilities of paternity exclusion allow an extremely precise level of individual identification, indicating that these microsatellite markers will be ideal for population genetic and parentage-type studies in E. leucoxylon. The markers also exhibited an average of 76% conservation within the subgenus Symphyomyrtus, to which E. leucoxylon belongs, and 53% conservation across other subgenera of Eucalyptus, demonstrating the potential of these markers in ecological and breeding studies in a wide range of Eucalyptus species.     

Development and characterization of microsatellite DNA markers for the Alpine plant species Campanula thyrsoides

We isolated and characterized eight polymorphic microsatellite markers for the Alpine plant species Campanula thyrsoides (Campanulaceae). Number of alleles per locus ranged from six to 12 and the observed heterozygosity was between 0.529 and 0.900. Observed vs. expected heterozygote deficits were significantly different in one out of eight loci following Bonferroni's correction for multiple tests. We did not find evidence for linkage disequilibrium between locus pairs. The microsatellite markers are being used for the study of genetic variation and gene flow within and among populations of C. thyrsoides in the Swiss Alps.     

Fully informative microsatellite markers for the tetraploid plant Eritrichium nanum (Boraginaceae)

We characterized eight polymorphic, codominant nuclear microsatellite loci in the tetraploid plant Eritrichium nanum. The different allelic configurations occurring under tetrasomic inheritance were fully resolved at all loci. Two natural populations showed high observed heterozygosities, which were in agreement with Hardy-Weinberg expectations. There was no evidence of genetic linkage disequilibrium for any pair of loci. The results suggest that these microsatellite markers are useful for mating system and population genetic analyses in high-alpine E. nanum.     

New polymorphic microsatellite loci for the Greek smooth newt, Lissotriton vulgaris graecus, and their utility in the nominotypical subspecies

Eight polymorphic microsatellites were isolated from the Greek smooth newt (Lissotriton vulgaris graecus) using a microsatellite enrichment protocol and selective hybridization with a biotinylated (AC)(11) probe. The loci showed different variation patterns in a single breeding population (32 individuals) with mean number of alleles at 5.0 and mean observed heterozygosity at 0.520. The amplification success also in the nominotypical subspecies favours the use of these microsatellite loci in population genetic analyses as well as in the study of contact zones between smooth newt subspecies.     

New polymorphic microsatellite markers for the summer flounder, Paralichthys dentatus

Given the ecological and commercial importance of the summer flounder (Paralichthys dentatus), there is a surprising paucity of information on the molecular genetics of this species. Some studies published to date are concentrated on the reproduction biology. To address this shortcoming, a microsatellite-enriched genomic DNA library of P. dentatus was generated and screened by sequencing. Twelve dinucleotide microsatellite loci were characterized by genotyping 24 samples. The observed number of alleles ranged from three to thirteen with an average of 8.25, while the effective number of alleles ranged from 2.21 to 8.28 with an average of 5.06. The observed and expected heterozygosities ranged from 0.0833 to 0.9583 and from 0.5594 to 0.8980, respectively. Significant deviations from Hardy–Weinberg expectations were detected at three loci and linkage disequilibrium between two loci was significant after applying Bonferroni correction. In cross-species amplification, three species showed at least two polymorphic loci. The 12 highly polymorphic microsatellite markers represent a powerful molecular tool, which will allow for detailed population genetic analyses on this important marine fish.     

New microsatellite markers in chicken optimized for automated fluorescent genotyping

We have isolated and developed 180 new polymorphic chicken microsatellite markers. In addition, primers have been developed for 91 microsatellites derived from the GenBank sequence database (isolated by the laboratory of Terry Burke, Leicester University), of which 89 were polymorphic, and six existing polymorphic markers (HUJ) have been modified. The primer sequences were designed to allow optimal performance of the markers, in sets containing multiple microsatellites, on ABI sequencers. The average number of alleles for the 275 polymorphic markers described was 4·0. Of these markers, 93% were polymorphic in the Wageningen resource population whereas 57% of the markers were polymorphic in the East Lansing reference population and only 44% could be mapped in the Compton reference population. The microsatellite markers described in this paper, in combination with the microsatellite markers published previously, are particularly well suited for performing a total genome scan for the detection of quantitative trait loci (QTL).     

New markers for new species: microsatellite loci and the East African cichlids

The radiation of the East African cichlid fishes has engaged biologists for over a century. Because so much taxonomic diversity has evolved recently, they are an ideal natural system in which to study the process of speciation. Hypervariable microsatellite loci have been used to verify multiple paternity and maternity in cichlid broods, to quantify the fitness of cooperative breeders and reproductive parasites, to estimate effective population sizes in captive populations, and to illuminate the spatial and temporal scale of gene flow among natural populations. The patterns that have emerged from these studies often reflect important biological differences among taxa. The cichlid species of East Africa represent a large amount of taxonomic and adaptive diversity all neatly packaged into a single lineage and confined to a modest geographical area. Data from microsatellite loci are now providing us with the means to understand one of the world's most intriguing and instructive comparative evolutionary systems.     

Isolation of compound microsatellite markers for the endangered plant Neolitsea sericea (Lauraceae)

? Premise of the study: The development of compound microsatellite markers was conducted in Neolitsea sericea to investigate genetic diversity and population genetic structure of this endangered insular species. ? Methods and Results: Using the compound microsatellite marker technique, 10 compound microsatellite markers that were successfully amplified showed polymorphism when assessed in 55 individuals from two populations in East China and Japan. Overall, the number of alleles ranged from 3 to 17, with an average of 7.9 alleles per locus. In addition, these primers could be easily amplified in Neolitsea aurata var. paraciculata and N. aurata var. chekiangensis. ? Conclusions: The highly polymorphic markers developed and characterized in this study will be useful for population genetic studies of N. sericea.     

连香树的组织培养和快速繁殖

1 植物名称 连香树（Cercidiphyllum japonicum Sieb．et Zucc．）。