突尼斯非洲跳鼠（Jaculus jaculus）和埃及跳鼠J.orientalis）群体的等位酶多态及遗传分化

运用16种酶蛋白编码的23个遗传座位对突尼斯非洲跳鼠(Jaculus jaculus)和埃及跳鼠(J.orientalis)自然群体的遗传变异和分化进行了电泳分析.结果表明,与其他啮齿动物等哺乳动物的相关数据比较,发现这两个种群体的遗传变异水平较低.非洲跳鼠群体的观测杂合度(Hobs)为0.08-0.19,多态座位百分比(P)为26.2%-45.2%,每个座何的平均等位基因数(A)为1.1-1.4;埃及跳鼠的Hobs为0.10-0.15,P为29.3%-44.1%,A为1.1-1.7.两个种群体各自的遗传分化程度较低(非洲跳鼠和埃及跳鼠的Fst分别为0.0017和0.0019).而两个种群体间的Fst为0.607(P＜0.05),表明两个种之间高度的遗传分化.本研究支持这两个种分类地位的合法性,并强调了地理因素(环境类犁和生物气候阶段)对两个种遗传结构的影响.     

Isolation and characterization of microsatellite loci in the beach pea, Lathyrus japonicus (Fabaceae), in Japan

? Premise of the study: Microsatellite loci were developed for Lathyrus japonicus (Fabaceae) to evaluate genetic diversity, population genetic structure, and demographic patterns of this species in Japan. ? Methods and Results: In total, eight primer sets were identified in Japanese populations of L. japonicus and polymorphisms were evaluated in 83 individuals from three populations, including the northern and southern geographic range in Japan. The number of alleles per locus ranged from four to 20, and gene diversity per locus ranged from 0.636 to 0.935 among three populations. In addition, six of the eight loci could be successfully amplified in L. pratensis. ? Conclusions: These markers will be useful for studies of genetic variations, genetic structure, and gene flow of L. japonicus, which is important to investigate the demographic patterns of this coastal plant. In addition, the primers are useful for further genetic structure analysis of L. pratensis.     

Development of microsatellite markers in heterostylous Hedyotis chrysotricha (Rubiaceae)

? Premise of the study: Microsatellite primers were developed for a heterostylous herb, Hedyotis chrysotricha to investigate the effect of habitat fragmentation on its genetic diversity and population structure. ? Methods and Results: Twelve primer sets were developed and their polymorphisms were tested on 47 individuals from two island populations of H. chrysotricha in Thousand Island Lake of China. The number of alleles per locus ranged from five to 10, with an average of seven alleles. Expected heterozygosity per locus ranged from 0.284 to 0.821 and observed heterozygosity ranged from 0.191 to 0.851. ? Conclusions: We showed that all of the 12 microsatellite markers developed for H. chrysotricha are polymorphic within populations, which should provide a powerful tool for assessing population structure and genetic diversity across fragmented and continuous populations, and for studying the genetic effects of habitat fragmentation on this species.     

珍稀濒危蕨类植物东方水韭的遗传多样性

采用ISSR分子标记对珍稀濒危蕨类植物东方水韭和中华水韭4个自然居群共72个样品进行了DNA多态性分析。从65个随机引物中筛选出11个有效引物,共产生98条DNA片段,其中68条为多态性条带,多态位点百分率(PPL)为66.33%。东方水韭两个居群的多态位点百分比率(PPL)较低(8.16%和7.14%)。中华水韭两个居群的PPL也较低(9.18%和23.47%)。中华水韭物种水平上的PPL(51.02%)高于东方水韭(9.18%)。AMO-VA分析结果表明,东方水韭遗传变异中主要存在于居群内(94.74%),而中华水韭绝大部分的遗传变异却存在于居群间(86.71%)。东方水韭和中华水韭个体间UPGMA聚类结果表明:同一物种的个体完全能聚在一起,中华水韭的两个居群也能明显分开,而东方水韭两居群的个体并不能完全聚在一起。探讨了可能造成上述居群遗传结构模式的主要因素,同时提出今后工作中需重点解决的问题。     

Development and characterization of 41 novel EST-SSR markers for Pisum sativum (Leguminosae)

? Premise of the study: Expressed sequence tag (EST)-derived simple sequence repeat (SSR) markers were developed in Pisum sativum for further use in genetic studies and breeding programs. ? Methods and Results: Forty-one novel EST-SSR primers were developed and characterized for size polymorphism in 32 Pisum sativum individuals from four populations from China. In each population, the number of alleles per locus ranged from one to seven, with observed heterozygosity and expected heterozygosity ranging from 0 to 0.8889 and 0 to 0.8400, respectively. Furthermore, 53.7% of these markers could be transferred to the related species, Vicia faba. ? Conclusions: The developed markers have potential for application in the study of genetic diversity, germplasm appraisal, and marker-assisted breeding in pea and other legume species.     

Development of microsatellite markers for the neotropical tree species Dipteryx alata (Fabaceae)

? Premise of the study: Microsatellite markers were developed for the population genetic analyses of the neotropical tree Dipteryx alata (Fabaceae). ? Methods and Results: Microsatellites were developed from a genomic shotgun library. Polymorphism at each microsatellite loci was analyzed based on 94 individuals from three populations. Eight loci amplified successfully and presented one to 10 alleles, and expected heterozygosities ranged from 0.097 to 0.862. Four loci also amplified in Pterodon emarginatus and presented similar polymorphism. ? Conclusion: The eight microsatellite primer pairs are potentially suitable for population genetic studies and successfully amplified in another Fabaceae species.     

Development of polymorphic microsatellite markers for Cymbidium goeringii (Orchidaceae)

? Premise of the study: Microsatellite markers were developed in Cymbidium goeringii to investigate its genetic diversity and population genetic structure. ? Methods and Results: From a microsatellite-enriched genomic library, 21 novel polymorphic microsatellites were isolated. The polymorphic patterns were verified in four populations (East Korea, West Korea, China, and Japan). The number of alleles per locus ranged from 11 to 29 with a mean of 20.29. The observed and expected heterozygosities varied from 0.272 to 0.799 and from 0.461 to 0.911, respectively. ? Conclusions: These microsatellite markers will be useful tools for understanding genetic variation and population ecogenetic structure in C. goeringii.     

Development of microsatellite loci for the endangered species Pityopsis ruthii (Asteraceae)

? Premise of the study: Microsatellite loci were developed for the endangered species Pityopsis ruthii and will permit genetic and conservation studies of the species. ? Methods and Results: A microsatellite-enriched library was used to develop 12 polymorphic microsatellite loci for P. ruthii. The loci amplified perfect and imperfect repeats with three to seven alleles per locus. Observed heterozygosity ranged from 0.05 to 0.80 and expected heterozygosity ranged from 0.23 to 0.75. ? Conclusions: These microsatellite loci provide a sufficient set of markers for further investigation of population genetics of P. ruthii.     

Microsatellite loci for Gossypium davidsonii (Malvaceae) and other D-genome, Sonoran Desert endemic cotton species

? Premise of the study: Microsatellite primers previously developed for domesticated cotton (Gossypium hirsutum; tetraploid) were screened for their utility in investigating genetic structure and gene flow within G. davidsonii and five other wild, Mexican, D-genome cotton species (all diploid). ? Methods and Results: We screened 50 microsatellite primer pairs from the Cotton Marker Database, identifying 10 loci as polymorphic within G. davidsonii. In genotyping approximately 200 individuals from four populations, we found that the number of alleles per locus ranged from seven to 17, and mean observed and expected heterozygosity ranged from 0.145 to 0.492 and from 0.436 to 0.734, respectively. We genotyped six to 20 individuals from each of the remaining species, finding these 10 loci to cross-amplify in all cases and in most cases to be polymorphic. ? Conclusions: These markers may be useful for further investigation of population genetics of G. davidsonii and other wild D-genome cotton species.     

Development and characterization of microsatellites in Torreya jackii (Taxaceae), an endangered species in China

? Premise of the study: Polymorphic microsatellite loci were developed in Torreya jackii, an endangered species in China, to provide markers for further studies on the genetic diversity of this species. ? Methods and Results: Eight polymorphic loci and one monomorphic locus were developed and characterized in four T. jackii populations (Xianju, Songyang, Pujiang, and Tonglu) from Zhejiang Province, China. The number of alleles per locus ranged from one to eight across 80 T. jackii individuals. At the eight polymorphic loci, the observed heterozygosity ranged from 0.150 to 1.000 and the expected heterozygosity ranged from 0.185 to 0.796. ? Conclusions: The microsatellite loci developed and characterized in this study will facilitate future analyses of the genetic diversity of T. jackii. Such information will aid in designing strategies to conserve this currently endangered species.     

Microsatellite markers for the native Texas perennial grass, Panicum hallii (Poaceae)

? Premise of the study: We developed microsatellites for Panicum hallii for studies of gene flow, population structure, breeding experiments, and genetic mapping. ? Methods and Results: Next-generation (454) genomic sequence data were used to design markers. Eighteen robust markers were discovered, 15 of which were polymorphic across six accessions of P. hallii var. hallii. Fourteen of the markers cross-amplified in a P. capillare accession. For the 15 polymorphic markers, the total number of alleles per locus ranged from two to 26 (mean: 11.0) across six populations (11-19 individuals per population). Observed heterozygosity (mean: 0.031) was 13.7 times lower than the expected heterozygosity (mean: 0.426). ? Conclusions: The deficit of heterozygous individuals is consistent with P. hallii having a high rate of self-fertilization. These markers will be useful for studies in P. hallii and related species.     

Isolation and characterization of novel microsatellite markers for Arctium minus (Compositae)

? Premise of the study: Microsatellite primers were developed for the invasive plant Arctium minus to investigate the effects of facultative self-pollination and the biannual habit on population genetic structure, as well as the colonization of the Americas by this Eurasian species. ? Methods and Results: Sixteen di- and trinucleotide microsatellite loci were identified in six populations. The number of alleles per locus ranged from one to 10, observed heterozygosities ranged from 0.000 to 0.897, and the mean value of F(IS) was 0.316. ? Conclusions: These results indicate the utility of these loci in future studies of population genetics in A. minus.     

Development of microsatellites in Machilus thunbergii (Lauraceae), a warm-temperate coastal tree species in Japan

? Premise of the study: Microsatellite markers were developed and characterized in a typically coastal, widespread, and dominant tree species of the evergreen broadleaf forests, Machilus thunbergii, for comparison of the genetic diversity and structure of inland populations surrounding the ancient Lake Biwa and coastal populations in Japan. ? Methods and Results: Eighteen polymorphic microsatellites of this species were isolated using an improved technique for isolating codominant compound microsatellite markers. These isolated loci provided compound simple sequence repeat (SSR) markers with polymorphisms of three to 19 alleles per locus, with an average of 10.9. The expected and observed within-population heterozygosities ranged from 0.16 to 0.86 and from 0.13 to 0.72, respectively. ? Conclusions: These markers may be useful tools for further investigation of the population genetic structure and biogeographic history of M. thunbergii in the warm-temperate zone of East Asia.     

Isolation and characterization of microsatellite markers for Plathymenia reticulata (Fabaceae)

? Premise of the study: Microsatellite loci were isolated and characterized for use in population genetic studies of Plathymenia reticulata (Fabaceae), a tropical tree widespread in the Atlantic Forest and cerrado biomes of South America. ? Methods and Results: Nine microsatellite markers were developed using a simple sequence repeat-enriched library. Polymorphism was analyzed in 51 individuals from two populations. All loci were polymorphic, with the number of alleles per loci ranging from five to 15 (mean number of alleles: 10.22). Observed and expected heterozygosities per loci and population ranged from 0.313 to 1.000 and 0.280 to 0.869, respectively. ? Conclusions: These highly informative loci are potentially useful to estimate population genetic structure and to understand evolutionary processes and taxonomy of the species.     

Intraspecific cytotypic variation and complicated genetic structure in the Phlox amabilis-P. woodhousei (Polemoniaceae) complex

? Premise of the study: Polyploidy is widely recognized as an important process in the evolution of plants, but less attention has been paid to the study of intraspecific polyploidy, including its prevalence, formation, taxonomic implications, and effect on genetic diversity, structure, and gene flow within and among individuals and populations. Here we studied intraspecific ploidy level variation in the Phlox amabilis-P. woodhousei complex to determine the amount and distribution of cytotypic and genetic variation present and measure the extent of gene flow among species, cytotypes, and populations. ? Methods: Flow cytometry and microsatellite analyses were used to ascertain cytotypic variation, genetic diversity, and population structure within and among eight populations of P. amabilis and 10 populations of P. woodhousei from Arizona and New Mexico. ? Key results: Our analyses support the recognition of P. amabilis and P. woodhousei as two distinct species. Both species exhibit cytotypic variation with geographically structured diploid, tetraploid, and hexaploid populations, and genetic analyses suggest a combination of auto- and allopolyploidy in their formation. Diploid, tetraploid, and most hexaploid populations within species share much of their genetic variation, while some hexaploid populations are genetically distinct. All populations maintain moderately high genetic diversity and connectivity, and genetic structure is strongly influenced by geography. ? Conclusions: This study highlights the potential for complicated patterns of genetic variation relative to cytotypic variation and provides evidence for the role of cytotypic variation and geographic isolation in shaping diversity, differentiation, and potentially speciation in the P. amabilis-P. woodhousei complex.     

Genetic diversity in <Emphasis Type="BoldItalic">Astragalus argaeus</Emphasis>, a critically endangered species from Turkey

Astragalus argaeus is critically endangered endemic species growing only on Erciyes Mountain in Kayseri. Inter simple sequence repeat (ISSR) markers were chosen to detect the genetic diversity in four populations of A. argaeus. Ten primers were used to assess the diversity among 96 genotypes collected from the four localities in Erciyes Mountain. A total of 78 bands were scored, of which 44 (55.8%) were polymorphic. The unweighted pair group method arithmetic average (UPGMA) and principle component analysis (PCoA) showed moderate genetic diversity at the species and population level. The percentages of polymorphic bands (PPB) ranged from 53.8 to 61.5 (58.01%?±?3.2) and average gene diversity (h) at the population and species level was estimated to be 0.17 and 0.23, respectively. The Shannon’s information index (SI) ranged from 0.24 to 0.29 at the population level and was 0.35 at the species level. The determined gene flow (Nm) was 1.83. The UPGMA tree indicated that the four populations were not genetically distinct obviously. In analysis of molecular variance (AMOVA), the percentage of the variance was 38.72% among populations and 61.28% within populations. The data which small population size, habitat fragmentation and moderate levels of genetic diversity demonstrate that A. argaeus possess threat of extinction if its narrow habitat is destroyed.     

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.     

Development and characterization of microsatellite markers for Berberis thunbergii (Berberidaceae)

? Premise of the study: Microsatellite markers were isolated and characterized in Berberis thunbergii, an invasive and ornamental shrub in the eastern United States, to assess genetic diversity among populations and potentially identify horticultural cultivars. ? Methods and Results: A total of 12 loci were identified for the species. Eight of the loci were polymorphic and were screened in 24 individuals from two native (Tochigi and Ibaraki prefectures, Japan) and one invasive (Connecticut, USA) population and 21 horticultural cultivars. The number of alleles per locus ranged from three to seven, and observed heterozygosity ranged from 0.048 to 0.636. ? Conclusions: These new markers will provide tools for examining genetic relatedness of B. thunbergii plants in the native and invasive range, including phylogeographic studies and assessment of rapid evolution in the invasive range. These markers may also provide tools for examining hybridization with other related species in the invasive range.     

Microsatellite primers for Halophila ovalis and cross-amplification in H. minor (Hydrocharitaceae)

?Premise of the study: Polymorphic microsatellite primers were developed in the seagrass Halophila ovalis to investigate genetic variation. ?Methods and Results: Ten polymorphic microsatellite loci were developed in Halophila ovalis. The number of alleles per locus ranged from 2 to 12 across 80 H. ovalis individuals. These loci were successfully amplified in H. minor, and four were monomorphic across 30 individuals. ?Conclusions: These results from four H. ovalis populations and one H. minor population show the broad utility of microsatellite loci in future studies of population genetics. Four distinct alleles were present in H. minor but absent in H. ovalis, indicating potential divergence between them.     

Polymorphic chloroplast microsatellite loci in Nelumbo (Nelumbonaceae)

? Premise of the study: To study population genetics, phylogeography, and hybridization of Nelumbo (Nelumbonaceae), chloroplast microsatellite markers were developed. ? Methods and Results: Seventeen microsatellite loci were identified from the chloroplast genomes of N. nucifera and N. lutea. Polymorphisms were assessed in three populations of N. nucifera and one population of N. lutea. Nine loci were found to be polymorphic in N. nucifera, and all 17 loci were found to be polymorphic in N. lutea. In N. nucifera, the number of alleles per locus ranged from two to six, and the unbiased haploid diversity per locus ranged from 0.198 to 0.790. In N. lutea, the number of alleles ranged from two to four, and the unbiased haploid diversity per locus ranged from 0.245 to 0.694. ? Conclusions: The identified chloroplast simple sequence repeat markers will be useful for the study of genetic diversity, phylogeography, and identification of Nelumbo cultivars.