Microsatellite markers for Spergularia media (L.) C. Presl. (Caryophyllaceae) and their cross-species transferability

We developed 11 polymorphic microsatellite markers for Spergularia media (Caryophyllaceae), a perennial halophyte of coastal salt meadows and continental areas of western Eurasia. The number of alleles per locus observed in a single population of 20 individuals from the German North Sea coast ranged from 3 to 20. Observed and expected heterozygosities ranged from 0.200 to 0.850 and from 0.278 to 0.936 respectively. Observed heterozygosities were lower than expected heterozygosities at all loci, presumably as a consequence of inbreeding. All markers cross-amplified in the closely related S. salina. Of these, nine were polymorphic in the heterologous species. Only two primer pairs generated PCR products in S. diandra.     

Development of polymorphic simple sequence repeat markers for Pisolithus microcarpus

Six polymorphic simple sequence repeat (SSR) markers were developed for the ectomycorrhizal fungus Pisolithus microcarpus. A polymerase chain reaction (PCR)‐based technique was used in which random amplified polymorphic DNA (RAPD) fingerprints were probed with labelled SSR oligonucleotides by southern hybridization. The number of alleles per locus ranged from two to nine with expected heterozygosity values from 0.33 to 0.76. These loci will be potentially useful for genetic structure and gene flow studies of P. microcarpus populations. Cross‐species amplification with Pisolithus albus isolates at all loci was also observed.     

How much effort is required to isolate nuclear microsatellites from plants?

The attributes of codominance, reproducibility and high resolution have all contributed towards the current popularity of nuclear microsatellites as genetic markers in molecular ecological studies. One of their major drawbacks, however, is the development phase required to obtain working primers for a given study species. To facilitate project planning, we have reviewed the literature to quantify the workload involved in isolating nuclear microsatellites from plants. We highlight the attrition of loci at each stage in the process, and the average effort required to obtain 10 working microsatellite primer pairs.     

Eight variable microsatellite loci for a Neotropical tree, Jacaranda copaia (Aubl.) D.Don (Bignoniaceae)

The Dendrogene Project (Genetic Conservation within Managed Forests in Amazonia) aims to understand the genetic and ecological processes that underpin tree species survival and in particular their response to forest management regimes. As part of the project, we developed eight microsatellite markers for Jacaranda copaia to be used for genetic structure, gene flow and reproductive biology studies. Polymorphism was evaluated using 96 adult trees from the Tapajos National Forest in the Eastern Brazilian Amazon. An average of 22 alleles per locus were detected, with expected heterozygosity ranging from 0.731 to 0.94.     

Microsatellite analysis in organelle genomes of Chlorophyta

Simple Sequence Repeats (SSRs) or microsatellites constitute a significant portion of genomes however; their significance in organellar genomes has not been completely understood. The availability of organelle genome sequences allows us to understand the organization of SSRs in their genic and intergenic regions. In the present work, SSRs were identified and categorized in 14 mitochondrial and 22 chloroplast genomes of algal species belonging to Chlorophyta. Based on the study, it was observed that number of SSRs in non-coding region were more as compared to coding region and frequency of mononucleotides repeats were highest followed by dinucleotides in both mitochondrial and chloroplast genomes. It was also observed that maximum number of SSRs was found in genes encoding for beta subunit of RNA polymerase in chloroplast genomes and NADH dehydrogenase in mitochondrial genomes. This is the first and original report on whole genomes sequence analysis of organellar genomes of green algae.     

Isolation and characterization of nine microsatellite markers for Brachypodium sylvaticum (Huds.) Beauv., a recently invasive grass species in Oregon

The patterns of genetic diversity caused by rapid range expansions following recent colonizations are best observed using highly polymorphic genetic markers. We characterized nine microsatellite markers for Brachypodium sylvaticum, a bunchgrass invasive in the Northwestern United States and native to Eurasia. Loci exhibited from two to 10 alleles, and generally had high F(IS) values. These loci will help identify sources of new populations in the region, and they will be useful for studying patterns of genetic diversity during rapid range expansions.     

Development and testing of novel chloroplast microsatellite markers for Lolium perenne and other grasses (Poaceae) from de novo sequencing and in silico sequences

Twelve primers to amplify microsatellite markers from the chloroplast genome of Lolium perenne were designed and optimized using de novo sequencing and in silico sequences. With one exception, each locus was polymorphic with a range from two to nine alleles in L. perenne. The newly developed primer pairs cross‐amplified in different species of Lolium and in 50 other grass species representing nine grass subfamilies.     

Microsatellite markers for the tetraploid halophyte Suaeda maritima (L.) Dumort. (Chenopodiaceae) and cross-species amplification in related taxa

We developed 12 polymorphic microsatellite markers for the tetraploid halophyte Suaeda maritima (Chenopodiaceae). Population genetic parameters were estimated for three populations from different habitats (coastal and inland), using the program Tetrasat. Between two and 15 alleles per locus were observed. Mean expected heterozygosities (H(E) ) and Shannon-Wiener Diversity Indices (H') per locus and population ranged from zero to 0.852, and from zero to 2.990, respectively. The two inland populations were less diverse than the coastal one at most of the loci. All markers cross-amplified in the closely related Suaeda salsa, and all but one were transferable to Suaeda spicata and Suaeda salinaria.     

Tetranucleotide microsatellite loci from the black bear (Ursus americanus)

We describe primers and polymerase chain reaction conditions to amplify 21 tetranucleotide microsatellite DNA loci in black bears (Ursus americanus). We tested primers using individuals from two populations, one each in Georgia and Florida. Among individuals from Georgia (n = 29), primer pairs yielded an average of 2.9 alleles (range, one to four) and an average observed heterozygosity (H_O) of 0.50 (range, 0.00 to 0.79). Among individuals from Florida (n = 19), primer pairs yielded an average of 5.7 alleles (range, one to 14) and an H_O of 0.55 (range, 0.00 to 1.00). A comparison of previously developed markers with individuals from Georgia suggests that bear populations in Georgia and Florida have reduced allelic diversity relative to other populations.     

基于景观敏感度的猴石森林公园保护区划

基于GIS技术,选取坡度、相对景点距离、相对游道距离、景点视觉几率和游道视觉几率5个指标分别对猴石森林公园进行敏感度评价,并建立了综合敏感度评价模型,运用层次分析法（AHP）确定各指标权重,进而确定了公园内各区域的综合敏感度等级,将公园相应地划分为4个等级的敏感区.结果表明：研究区Ⅲ级敏感区的面积最大,为495.80 hm²,占公园总面积的38.3%.这一区域在强调保护自然景观的同时,可进行适度开发,提倡利用人文景观美化和衬托自然景观.Ⅳ级敏感区的面积最小,为142.80 hm²,占研究区总面积的11.0%.这一区域的开发潜力最大,可开展大规模的综合性旅游设施和游道布设.Ⅰ、Ⅱ级敏感区的面积依次为297.24和359.72 hm²,分别占研究区总面积的22.9%和27.8%,Ⅰ级敏感区内景观应严格保护,禁止任何人为开发建设,维持自然景观的本色,Ⅱ级敏感区内除简易的林间小道和石阶山道外,严禁开山取石、破坏植被和水体.