摘要：A simple and efficient method was presented for isolating microsatellite DNA markers from peanut (Arachis hypogaea L.) genome. The genomic DNA was converted into pre-amplified AFLP fragments and hybridized with biotin-labeled SSR probes. Then the hybrid mixture was used to incubate with magnetic beads coated with streptavidin. After washing to remove the non-SSR fragments, the eluted single-strand DNA, which was cloned and sequenced, was largely enriched for microsatellites. Primers can then be designed according to the sequence flanking the repeat motifs and used for polymorphism analysis. The whole experiment can be completed within one week and can be employed as a reliable option for any molecular laboratory to develop SSR markers.

摘要：microsatellite DNA technique was used to detect the genetic variation between five hatchery populations of the Pacific oyster from China and two wild populations from Japan. Seven microsatellite loci screened in this study showed high polymorphism in both hatchery and wild populations, as observed in an average number of allele per locus （19.1-29.9） and average expected heterozygosity （0.916-0.958）. No significant difference in average allelic richness or expected heterozygosity was observed between Chinese hatchery populations and Japanese wild populations. Pairwise Fsr values and heterogeneity tests of allele frequencies showed significant genetic differentiation between all populations. According to the neighbor-joining tree constructed on the basis of the Dc distance, the seven populations fell into three groups showing a clear division between hatchery and wild populations, and between the northern and southern hatchery populations. Assignment tests correctry assigned high percentages （97%-100%） of individuals to their original populations and demonstrated the feasibility of microsatellite analysis for discrimination between populations. The information obtained in this study is useful for designing suitable management guidelines and selective breeding programs for the Pacific oyster in China.

摘要：In cultivated rice ( Oryza sativa L.), F-1 pollen sterility is controlled by at least 6 loci of the F, pollen sterility genes. To map S-b, one of loci, rice variety Taichung 65 (T65) carrying S-b(j)/S-b(j) and its near-isogenic line TIST2 carrying S-b(i)/S-b(i) were used to develop the mapping population. One hundred and fifty-eight microsatellite markers were selected to survey T65 and TISL2. RM13 on chromosome 5 was found to be polymorphic between them. Cosegregation indicated that RM13 was closely linked with locus S-b. Eleven RFLP markers were selected on the corresponding region from the genetic map of Rice Genome Research Program (RGP) of Japan to convert into sequence-tagged site (STS) markers. Amplicon length polymorphism (ALP) was carried out, but none of them was found to be polymorphic between T65 and TISL2. Then PCR-based RFLP (PBR) was done using six 4-nucleotide recognizing restriction endonucleases. Polymorphism was detected when PCR products of R830STS and R2213SSTS were digested with Taq I. Genetic analysis indicated that the distance between locus S-b and markers, R830STS, RM13 and R2213SSTS were 3.3 cM (centi-Morgan), 5.2 cM and 5.5 cM, respectively. These PCR-based markers could be directly used in marker-assisted selection. The technical system combining genetic mapping and PCR-based marker-assisted selection will facilitate the development of molecular breeding.

摘要：A library rich in CA/GT microsatellites was constructed from the Paralichthys olivaceus genome by combining biotin capture method and radioactive labeling hybridization. Five hundred and twenty six positive clones were obtained through twice screens. Sequencing confirmed 133 microsatellite loci （number of repeats t〉 5） in 119 positive clones. Of these microsatellites, two （1.5%） had compound repeat motifs, 63 （47.37%） had perfect motifs and 68 （51.13%） had imperfect motifs. Primer pairs were designed in the flanking regions of 22 microsatelites and subjected to PCR amplification. In 8 artificial gynogenesis families, four pairs failed to amplification, one pair was monomorphic, and the rest were polymorphic with an average of 5.2 alleles per locus. Heterozygosities ranged between 0. 375 and 0. 846, PIC ranged between 0. 305 and 0. 823. The results suggested that most of the microsatellites we isolated were qualified to be applied to the population genetic studies of P. olivaceus.

摘要：[Objective] This research aimed to develop walnut EST-SSR markers and design corresponding primers.[Method] 5213 EST sequences of walnut（Juglans regia Linn.） public online in NCBI were used for character analysis with bioinformatics methods,and primers were designed for the selected EST sequences by using Primer 3.0 software.[Result] 207 SSRs were obtained from the EST sequences,including 188 non-redundant sequences,the detection rate was 3.97% with an average distribution distance of 21.12 *** 92 types of repeat motifs were involved,which were mainly composed of dinucleotide and trinucleotide,accounting for 31.40% and 35.27% of the total number of repeat motifs,respectively.30 pairs of primers were initially selected from the 50 randomly-selected SSR primers by PCR amplification.[Conclusion] This research would lay foundations for the development of EST-SSR molecular markers in walnut and design of the targeted EST-SSR primers by mining and analyzing the SSR sites in walnut EST sequences.

摘要：Understanding the intra-population genetic diversity and population genetic structure is beneficial for plant protection and *** huoshanense is an endangered authentic medicinal *** analyze the population differentiation and genetic diversity in ***,simple sequence repeat(SSR)markers were obtained by high-throughput transcriptome sequencing,and 10 expressed sequence tag(EST)-SSRs were studied in 182 Dendrobium individual samples from 15 populations distributed in Huoshan County,southwest Anhui *** deep sequencing of *** transcriptome,a total of 58202 unigenes were obtained,and 7781 SSRs with 1~6 base repeats were *** them,dinucleotide SSRs were the dominant repeating motifs(3119,40.085%),and the most common was AG/CT(2666,54.01%).Ten SSR primers were screened out from the designed 120 primer pairs for further polymorphism *** results showed that 75 alleles were detected,and the number of alleles at each locus ranged from 4 to 11,with an average of *** mean expected heterozygosity(H_(e)),observed heterozygosity(H_(o))and polymorphism information content(C_(pi))of the 10 SSR loci were 0.646,0.574,and 0.607,*** populations exhibited a high level of genetic diversity(H_(o)=0.591,H_(e)=0.557)and a moderate level of differentiation(F_(ST)=0.10069),and the genetic variation mainly existed within *** results of Structure and neighbour-joining(NJ)analysis based on 10 polymorphic primers showed that *** populations were clustered into 2 groups,and the populations KS,HSD,and JXZ had rich genetic diversity and multiple private alleles,suggesting that these populations could be used for genetic improvement of the *** study revealed frequency distribution of *** SSR loci,and successfully developed microsatellite genetic markers,which are expected to expand the repertoire of DNA markers for genetic study of ***.

摘要：From the NCBI database, 81,518 Lactuca sativa EST sequences were downloaded, from which 61,757 non-redundant sequences were obtained. In total, 2040 SSR loci were identified, with the frequency of 3.3%. Trinucleotide repeat was dominant, followed by dinucieotide and hexanucleotide repeats. Among 181 types of repeat motifs, （AGA）n and （ATG）n were the dominant repeat motif types, taking up 12.01% and 3.53%, respectively. Totally, four material-special EST-SSR markers were characterized. This study enriches molecular markers of L. sativa, and also lays a theoretical foundation for following germplasm identification, molecular marker assisted breeding and genetic map construction.