元江鲤种群遗传多样性

选择12对微卫星标记检测了于2011年采集自元江(红河上游中国江段)5个样点192尾鲤的群体遗传多样性.共检测到201个等位基因,每个位点等位基因2-27个.各群体各位点平均等位基因(NA)12.25-14.67个,平均有效等位基因(NE)8.28-9.73个,平均观察杂合度(Ho)o.7765-0.8037,平均期望杂合度(HE)0.7761-0.8080,平均多态信息含量(PIC)0.7534-0.7843.元江鲤种群192个个体各位点NA、NE、Ho、HE、PIC分别为16.50、11.26、0.7927、0.8049、0.7966,种群遗传多样性水平高.元江鲤群体之间遗传分化小,可作为一个种群管理单元进行管理.增殖放流要防止遗传多样性丧失.     

Development of thirty-five novel polymorphic microsatellite markers in Pseudosciaena polyactis (Perciformes:Sciaenidae) and cross-species amplification in closely related species,Pseudosciaena crocea

Small yellow croaker, Pseudosciaena polyactis, is an economically important marine fishery species. In this study, we isolated 35 novel polymorphic microsatellite primers in P. polyactis by using the combined biotin capture method. The polymorphism of each locus was assessed in 30 individuals from Donggang, Northern Yellow Sea, China. A total of 519 alleles were detected and the number of alleles per locus ranged from 3 to 23. The PIC values of these 35 microsatellite loci ranged from 0.367 to 0.940. The observed (H_o) and expected heterozygosity (H_e) per locus ranged from 0.233 to 1.000 and from 0.438 to 0.943, respectively. Seven loci significantly deviated from Hardy–Weinberg equilibrium (HWE) after Bonferroni correction and no significant linkage disequilibrium (LD) was found between pairs of loci. In addition, cross-species amplification was performed in Pseudosciaena crocea, a closely related species of P. polyactis, to assess the applicability of these markers. These polymorphic microsatellites will provide useful tools for the study of genetic diversity and population structure of P. polyactis and P. crocea.     

Isozyme analysis of genetic variability and population structure of Lactuca L. germplasm

Isozymes were used to investigate the genetic variability, population structure, and relationships of Lactuca germplasm. The isozyme systems revealed 16 putative loci of a total of 31 alleles. Out of these 16 loci, 11 were polymorphic. The average values of expected heterozygosity (H_e), observed heterozygosity (H_o), mean number of alleles per locus (A) and effective number of alleles per locus (A_e) were 0.2227, 0.266, 1.3005 and 1.369, respectively. The average fixation indices were lower than zero for most of the accessions studied, indicating an excess of heterozygotes. Genetic differentiation among accessions (F_ST) exhibited that 51.3% of the isozyme variation was recorded among accessions, and 48.7% of the genetic variation resided within accessions. The average values of total heterozygosity (H_T) and intra-accessional genetic diversity (H_S) were 0.352 and 0.171, respectively. Moreover, the inter-accessional genetic diversity (D_ST) ranged from 0 to 0.424 with an average of 0.18. Cluster analysis revealed that L. sativa cultivars were distributed throughout different Lactuca species. Thereby, isozymes results confirms the hypothesis of the polyphyletic origin of L. sativa. This high level of genetic variation proved that isozymes are efficient for polymorphism analysis of Lactuca germplasm.     

跨种扩增筛选大鳄龟微卫星标记及遗传多样性分析

跨种扩增是一种能够快速、有效地获得物种微卫星标记的方法。本研究利用在近缘种中已发表的微卫星DNA引物,对大鳄龟（Macroclemys temminckii）进行跨种PCR扩增,在合成的69对引物中获得8对具有多态性的微卫星位点。对PCR扩增产物进行统计,得出观测杂合度（H_o）的范围是0.041 7~0.954 5,平均为0.384 8;期望杂合度（H_E）的范围为0.041 7~0.811 8,平均为0.479 1;多态信息含量范围为0.040 0~0.759 2,平均为0.423 2;经过卡方检验后,部分微卫星位点符合哈迪-温伯格平衡。总体来说,这些位点是研究大鳄龟遗传结构的良好分子标记。     

Development of microsatellite markers in Qualea grandiflora (Vochysiaceae) and transferability to congeneric species,typical trees of the Brazilian savanna

This study aimed to isolate and characterize microsatellite markers for Qualea grandiflora and to test their transferability to congeneric species Qualea multiflora and Qualea parviflora. These three species are widespread in the Cerrado, the largest, richest and probably the most threatened tropical savanna in the world. We characterized ten markers in 40 individuals belonging to two populations of Q. grandiflora and eight markers in 20 individuals belonging to one population of Q. multiflora and Q. parviflora. In Q. grandiflora, considering all 40 analyzed individuals, the number of alleles per locus ranged from eight to 21, and the average was 11.60. The mean number of alleles per locus was 8.8 and 7.3 in each population. The observed and expected heterozygosities (H_o and H_e) within populations varied from 0.235 to 0.944 and from 0.225 to 0.932, respectively. In Q. multiflora the number of alleles varied from two to 11 with an average of 5.75; the H_o ranged from 0.150 to 0.950, while H_e ranged from 0.191 to 0.817. In Q. parviflora, considering the seven polymorphic loci, the number of alleles ranged from two to 13, with an average of 7.5, while H_o ranged from 0.211 to 0.944, and H_e ranged from 0.193 to 0.906. The polymorphism level of the microsatellite markers here described enable them as powerful tools for future population genetic studies in these species, helping to answer ecological and evolutionary questions.     

Development of microsatellite marker loci for European hazelnut (<Emphasis Type="Italic">Corylus avellana</Emphasis> L.) from ISSR fragments

Polymorphic microsatellite markers were developed for European hazelnut (Corylus avellana L.) from the sequences of inter-simple sequence repeat (ISSR) fragments and flanking regions. Twenty-five ISSR primers were used to generate fragments for cloning. Of the 520 unique sequences obtained, 41 contained long internal repeats (≥20 bp) with flanking sequences sufficient for primer design. From these, we developed 23 new polymorphic microsatellite loci. The flanking sequences were obtained for fragment ends by chromosome walking, and an additional 47 polymorphic markers were developed. Two additional polymorphic markers were developed from a GA-enriched library. The 72 new marker loci were characterized using 50 diverse hazelnut accessions. For the internal repeat loci, the number of alleles per locus ranged from 2 to 16, with a mean of 7.52. Mean values for expected heterozygosity (H_e), observed heterozygosity (H_o), and polymorphism information content (PIC) were 0.62, 0.59, and 0.58, respectively. The estimated frequency of null alleles (r) was ≥0.05 at six of the 23 loci. For the 47 marker loci developed from fragment ends, the number of alleles per locus ranged from 2 to 16, with a mean of 7.30. Mean values for H_e, H_o, and PIC were 0.62, 0.47, and 0.58, respectively. The estimated frequency of null alleles (r) was ≥0.10 at 18 of the 47 loci. Of the 70 loci developed from ISSR and flanking sequences, 50 segregated in our mapping population and were assigned to linkage groups.     

Development and use of novel SSR markers for molecular genetic diversity in Italian millet (Setaria italica L.)

Italian millet is a commercially important grain crop. Nineteen polymorphic simple sequence repeat (SSR) markers, developed through construction of an SSR-enriched library from genomic DNA of Italian millet (Setaria italica L., P. Beauv.), were used for assessment of molecular genetic diversity against 40 accessions of S. italica. In total, 85 alleles were detected, with an average of 4.5 alleles per locus. The average gene diversity and polymorphism information content (PIC) values were 0.412 and 0.376, ranging from 0.02 to 0.88 and from 0.02 to 0.87, respectively. Values for observed (H _O) and expected (H _E) heterozygosities ranged from 0 to 0.73 and from 0.03 to 0.89, respectively. Nine loci deviated from Hardy-Weinberg equilibrium. The mean similarity coefficient among accessions was 0.6593. Based on the UPGMA algorithm, six different groups were successfully identified. In this clustering analysis, all Korean accessions grouped in one cluster, indicating that Korean accessions are genetically quite distinct from other introduced accessions. These newly developed microsatellite markers should be very useful tools for several genetic studies, including an assessment of diversity and population structure in Italian millet.     

Polymorphic microsatellite markers in Thrips hawaiiensis (Thysanoptera: Thripidae)

Thrips hawaiiensis (Morgan, 1913) is an important insect pest of fruits and vegetables. At present, it is primarily distributed in tropical and subtropical area. For a better understanding of the genetic makeup and migration patterns of T. hawaiiensis throughout the world, we isolated 11 novel polymorphic microsatellite loci from an enriched genomic library based on a biotin/streptavidin capture protocol. Genetic parameters were estimated on 80 individual thrips from two natural populations. The results showed that all 11 loci were highly polymorphic; the number of alleles ranged from six to 37, and nine loci demonstrated polymorphic information content (PIC) > 0.5. The observed (H _O) and expected (H _E) heterozygosities ranged from 0.350 to 0.925 and 0.307 to 0.952, respectively. Furthermore, only four locus/population combinations significantly deviated from Hardy–Weinberg equilibrium (HWE). These microsatellite markers have potential utility in population structure and gene flow studies of this species.     

Isolation and characterization of 15 polymorphic microsatellite markers for the fig-pollinating wasp,Blastophaga nipponica (Hymenoptera: Agaonidae)

We developed microsatellite markers for the fig-pollinating wasp Blastophaga nipponica Grandi using a dual-suppression-PCR technique. Twenty-one candidates of microsatellite loci were obtained, of which 15 yielded scorable patterns. The degree of polymorphism for the 15 loci was further characterized using summary statistics describing the genetic variation in 60 individuals from three natural populations in Japan. All 15 loci were polymorphic and yielded 2–27 alleles per locus. Overall observed heterozygosity (H _O) and expected heterozygosity (H _E) were 0.465 and 0.631, respectively. As expected, based on the inbreeding tendency of this species, the mean inbreeding coefficient (F _IS) was high (= 0.255). These markers will contribute to studies on the population structure of this species.     

Genetic Diversity of Some Pear Cultivars and Genotypes Using Simple Sequence Repeat (SSR) Markers

The genetic diversity and relationships among 47 pear cultivars and genotypes (Pyrus spp.), including 4 Japanese pears (Pyrus pyrifolia), 40 European pears (Pyrus communis), 1 Chinese pear (Pyrus bretschneideri) as well as 2 wild relatives (Pyrus salicifolia and Pyrus mazandaranica) were studied using 28 microsatellite primer pairs. A total of 174 alleles were produced at the 28 SSR loci with their sizes ranging from 81 to 290?bp. The number of observed alleles for each locus ranged from 3 (TsuENH014 and TsuENH046) to 12 (NB103a), with an average of 6.21 alleles per locus. In some SSR loci, more than two alleles were amplified in some cultivars and genotypes, suggesting that duplication has occurred in those accessions. This information suggests that at least two genomic regions exist for these loci in the pear genome. The observed heterozygosity (H _o) values of amplified loci ranged from 0.17 (TsuENH006) to 0.97 (NB103a). Shannon's information index (I) value was observed to be highest (2.14) in the NB103a locus, while the TsuENH006 locus had the lowest value with an average of 1.37 among SSR loci. The Dice genetic similarity coefficient ranged from 0.29 (??Nijisseiki?? and P. mazandaranica) to 0.91 (??Chojuro?? and ??Nijisseiki??) among samples. UPGMA cluster analysis showed two major groups corresponding to the Japanese and European pears.     

Isolation and characterization of variable microsatellite loci in Lilium philadelphicum (Liliaceae)

Here we describe the characterization of six polymorphic microsatellite loci for Lilium philadelphicum (Liliaceae). Polymorphism levels ranged from 7 to 30 alleles per locus with a mean number of 15 alleles per locus. Observed heterozygosity (H_O) ranged from 0.17 to 0.82 and did not deviate from Hardy–Weinberg expectations in the three western Montana populations included in the analysis. These loci are proving useful in studying gene flow between populations of this species distributed across its range in North America.     

Characterization of new microsatellite loci in Pieris amamioshimensis (Ericaceae), a species nearly extinct in the wild

A set of 11 polymorphic microsatellite markers has been developed and characterized for the critically endangered species Pieris amamioshimensis. Fifty‐nine individuals of an ex‐situ population were used to identify these markers. The total number of alleles for each locus ranged from 3 to 9, with an average of 5.4. The expected heterozygosities (H_S) and observed heterozygosities (H_O) ranged from 0.47 to 0.77 and 0.22 to 0.88, respectively. In total, four loci exhibited significant deviations from Hardy–Weinberg equilibrium: two loci showed significant heterozygosity excess and the other two loci showed significant heterozygosity deficit. The polymorphism information content (0.43 ≤ PIC ≤ 0.73), the probability of exclusions (PE₁ = 0.9565, PE₂ = 0.9969 and PE₃ = 0.9999) and probabilities for identity (PI = 3.78 × 10^?9 and PI‐Sib = 2.35 × 10^?4) suggest that these markers are useful for estimating not only genetic diversity but also parentage, for the ex‐situ conservation management of populations.     

Genetic diversity and variation in wild populations of dark sleeper (Odontobutis potamophila) in China inferred with microsatellite markers

Twenty-one highly variable microsatellite loci were used to investigate the genetic diversity and variation of Odontobutis potamophila in China. A total of 160 samples from five wild populations (Dangtu, Sheyang, Yuyao, Minjiang and Donxishan) were genotyped. All of the 21 microsatellite loci tested in this study showed polymorphism. The number of allele per locus ranged from 5.05 to 9.90. Locus 87a of Minjiang population had a 259-bp characteristic allele. The average observed heterozygosity and expected heterozygosity ranged from 0.33 to 0.62 and from 0.40 to 0.70, respectively. The pair-wise F_ST tests and NJ trees of the five O. potamophlia populations revealed that Dangtu, Sheyang, Yuyao and Dongxishan were genetically close to one another and distinct from Minjiang. Far genetic distances were observed among populations from distant geographical areas. This result provided guide for the use of O. potamophila breeds and the protection of the species.     

Characterization of polymorphic microsatellite loci in the aphid species Macrosiphum euphorbiae (Hemiptera: Aphididae)

Fourteen microsatellite loci were isolated and characterized in the potato aphid, Macrosiphum euphorbiae Thomas, by screening a genomic library with the oligonucleotide probes (GA)₁₀ (GT)₁₀ and (GATA)₄. Allelic diversity was estimated in samples collected from potato fields in Tunisia. Ten loci displayed polymorphism that ranged from two to four alleles per locus and the observed heterozygosity ranged from zero to one. These markers could be used to study the population genetic structure of this polyphagous aphid species.     

Isolation and characterization of 19 polymorphic microsatellite loci from Neosalanx taihuensis,a rapidly invasive and adaptative species

Neosalanx taihuensis can very rapidly adapt to new environmental conditions and quickly becomes the dominant species when introduced to lakes and reservoirs. To better understand the genetic mechanism responsible for this remarkable ability to invade and adapt to diverse ecosystems, 19 polymorphic microsatellite loci were isolated from the genomic DNA of N. taihuensis. These microsatellite loci were identified from 24 individuals from an invasive population sampled in Fuxian Lake, Yunnan Plateau, Southwest China. The number of alleles per locus ranged from 2 to 14. Observed and expected heterozygosities ranged from 0.0417 to 0.8636 and from 0.3112 to 0.9202, respectively. The polymorphism information content (PIC) varied from 0.2583 to 0.8928. These microsatellite loci will be essential in performing molecular analyses of genetic diversity and genetic structure in the future. This will ultimately facilitate better understanding of the genetic mechanisms that allow N. taihuensis to successfully invade and adapt to new ecosystems.     

Microsatellite loci for studies on population differentiation and connectivity of the red‐bellied yellow tail fusilier,Caesio cuning (Caesionidae)

Ten polymorphic microsatellites were isolated from the red‐bellied yellow tail fusilier Caesio cuning, a reef‐associated fish which occurs widely in the Indo‐Pacific region. The species is exploited by both small‐scale and commercial fisheries. Fifty individuals from six populations were genotyped using primers that reliably amplified 10 polymorphic loci. The number of alleles per locus ranged from three to 11. Observed heterozygosity (H_O) and expected heterozygosity (H_E) ranged between 0.400 to 0.880 and 0.337 to 0.843, respectively. These microsatellite loci may be used to study population structure, genetic diversity and connectivity of C. cuning in the range of its distribution.     

白条草蜥多态性微卫星位点的分离与鉴定

白条草蜥(Takydromus wolteri)是一种年产多窝卵的蜥蜴。为了对其婚配制度、同一雌性个体所产卵的窝内和窝间的父权状况、种群的遗传结构和物种的进化历史等研究内容进行探讨,本研究筛选出白条草蜥的9个具有高度多态性的微卫星位点。微卫星位点筛选自包含(AC)n和(ATAG)n重复片度的微卫星富集文库。在白条草蜥安徽滁州种群的16～32个个体中对上述位点进行检测后发现,上述座位的等位基因数目范围为12～20个,期望杂合度范围为0.894～0.955,观测杂合度范围0.565～0.938,表明这些微卫星标记具有良好的遗传多样性,它们将在白条草蜥的种群遗传结构、基因流水平、种群分化和婚配制度的研究中发挥重要作用。     

Development and characterisation of microsatellite markers for the medicinal plant Scutellaria baicalensis (Lamiaceae)

Scutellaria baicalensis is a popular medicinal plant that is on the verge of extinction due to uncontrolled harvesting, habitat destruction and deterioration of its ecosystem. We isolated and characterised 21 microsatellite loci in this species. Ninety-four individuals from six populations were used to test the polymorphism of the microsatellite loci. The number of alleles per locus ranged from 1 to 13, with a mean of 7.2. Observed and expected heterozygosities varied from 0.000 to 1.000 and 0.000 to 0.938, respectively. Among these new microsatellite markers, only two loci showed significant deviation from Hardy–Weinberg equilibrium. No locus pairs showed significant linkage disequilibrium. The 21 primer pairs were tested in other Scutellaria species. Most of these primer pairs worked successfully, except for Scut18. These new microsatellite markers could be applied to investigate the genetic diversity and population genetic structure of S. baicalensis and its closely related species.     

Microsatellite loci developed for black-crowned night-heron (Nycticorax nycticorax) and their cross-amplifications in Ardeidae

The present study reports isolation and characterization of 11 polymorphic microsatellite markers for Nycticorax nycticorax. A total of 82 alleles were detected with an average of 7.5 alleles per locus. The observed heterozygosity (H _O) ranged from 0.25 to 1.00, and the expected heterozygosity (H _E) ranged from 0.51 to 0.88. Analyses revealed no evidence for Linkage disequilibrium between any two loci, and only one locus was significantly deviated from HWE with the estimation of exact P values by the Markov chain method (P < 0.001). The 11 loci were successfully amplified in 11 other Ardeidae species. These results demonstrate these markers can be used for the study of intra- and inter-specific genetic diversity.     

Isolation and characterization of 18 polymorphic microsatellite loci from freshwater pearl mussel (<Emphasis Type="Italic">Cristaria plicata</Emphasis>)

Cristaria plicata was an important freshwater mussel for pearl culture in China. 18 polymorphic microsatellite markers were isolated and characterized using (CA)₁₅-enriched genomic library of C. plicata. These loci showed high levels of genetic polymorphism testing on 60 individuals sampled from Poyang Lake of Jiangxi Province, China. The number of alleles per locus ranged from 4 to 18. The expected (H _E) and observed heterozygosities (H _O) were 0.7232–0.8961 and 0.0000–1.0000, respectively. Four microsatellite loci were significantly deviated from Hardy–Weinberg equilibrium and no linkage disequilibrium was found. These microsatellite loci will be useful for assessment of genetic diversity and population structure in C. plicata.