Genetic diversity among silkworm (Bombyx mori L., Lep., Bombycidae) germplasms revealed by microsatellites

Genome ◽  
2005 ◽  
Vol 48 (5) ◽  
pp. 802-810 ◽  
Author(s):  
Muwang Li ◽  
Li Shen ◽  
Anying Xu ◽  
Xuexia Miao ◽  
Chengxiang Hou ◽  
...  

To determine genetic relationships among strains of silkworm, Bombyx mori L., 31 strains with different origins, number of generations per year, number of molts per generation, and morphological characters were studied using simple sequence repeat (SSR) markers. Twenty-six primer pairs flanking microsatellite sequences in the silkworm genome were assayed. All were polymorphic and unambiguously separated silkworm strains from each other. A total of 188 alleles were detected with a mean value of 7.2 alleles/locus (range 2–17). The average heterozygosity value for each SSR locus ranged from 0 to 0.60, and the highest one was 0.96 (Fl0516 in 4013). The mean polymorphism index content (PIC) was 0.66 (range 0.12–0.89). Unweighted pair group method with arithmetic means (UPGMA) cluster analysis of Nei's genetic distance grouped silkworm strains based on their origin. Seven major ecotypic silkworm groups were analyzed. Principal components analysis (PCA) for SSR data support their UPGMA clustering. The results indicated that SSR markers are an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in the silkworm.Key words: silkworm, Bombyx mori L., microsatellites, simple sequence repeat (SSR), genetic diversity.

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 471
Author(s):  
Jae-Ryoung Park ◽  
Won-Tae Yang ◽  
Yong-Sham Kwon ◽  
Hyeon-Nam Kim ◽  
Kyung-Min Kim ◽  
...  

The assessment of the genetic diversity within germplasm collections can be accomplished using simple sequence repeat (SSR) markers and association mapping techniques. The present study was conducted to evaluate the genetic diversity of a colored rice germplasm collection containing 376 black-purple rice samples and 172 red pericarp samples, conserved by Dong-A University. There were 600 pairs of SSR primers screened against 11 rice varieties. Sixteen informative primer pairs were selected, having high polymorphism information content (PIC) values, which were then used to assess the genetic diversity within the collection. A total of 409 polymorphic amplified fragments were obtained using the 16 SSR markers. The number of alleles per locus ranged from 11 to 47, with an average of 25.6. The average PIC value was 0.913, ranging from 0.855 to 0.964. Four hundred and nine SSR loci were used to calculate Jaccard’s distance coefficients, using the unweighted pair-group method with arithmetic mean cluster analysis. These accessions were separated into several distinctive groups corresponding to their morphology. The results provided valuable information for the colored rice breeding program and showed the importance of protecting germplasm resources and the molecular markers that can be derived from them.


2006 ◽  
Vol 86 (1) ◽  
pp. 251-257 ◽  
Author(s):  
Zhao Weiguo ◽  
Zhou Zhihua ◽  
Miao Xuexia ◽  
Wang Sibao ◽  
Zhang Lin ◽  
...  

The genetic diversity of 27 mulberry (Morus spp.) genotypes mainly from China was investigated using inter-simple sequence repeat (ISSR) markers to assist in addressing breeding objectives and conserving existing genetic resources. Of the 22 primers screened, 15 produced highly reproducible ISSR bands. Using these 15 primers, 138 discernible DNA fragments were generated with 126 (91.3%) being polymorphic, indicating considerable genetic variation among the mulberry genotypes studied. Genetic similarity ranged from 0.6014 between Yu 2 and Yu 711 to 0.9493 between Cuizhisang and Dejiang 10. The phenetic dendrogram based on ISSR data generated by the unweighed pair group method with arithmetical averages (UPGMA) method grouped the 27 accessions into two major clusters: cluster I, cultivated mulberry species (M. multicaulis Perr., M. alba Linn., M. atropurpurea oxb., M. bombycis Kiodz., M. australis Poir., M. rotundiloba Kiodz., M. alba var. pendula Dipp., M. alba var. macrophylla Loud., and M. alba var. venose Delile.); and cluster II, wild mulberry species (M. cathayana Hemsl., M. laevigata Wall., M. wittiorum Hand-Mazz., M. nigra Linn., and M. mongolica Schneid.). Our molecular analyses agree with the existing morphological classification of Morus and clarify the genetic relationships among mulberry species. Key words: Morus L., genetic diversity, inter-simple sequence repeat, relatedness


2007 ◽  
Vol 5 (02) ◽  
pp. 71-81 ◽  
Author(s):  
Serge Tostain ◽  
Clément Agbangla ◽  
Nora Scarcelli ◽  
Cédric Mariac ◽  
Ogoubi Daïnou ◽  
...  

Guinea yam (Dioscorea rotundataPoir.) is a dioecious vegetatively propagated tuber crop. It is widely cultivated by traditional techniques in West Africa, its area of origin. The genetic diversity of 146 accessions from Benin was analysed using 10 polymorphic simple sequence repeat (SSR) nuclear markers and agromorphological traits. An average of 8.4 alleles per locus was detected. The mean heterozygosity was 0.57 and the mean polymorphism information content (PIC) for polymorphic markers was 0.51. Some cultivars (23%) were found to have an identical genotype for the 10 markers. The structure of the genetic diversity observed in Benin is the result of farmers' crop management practices and their know-how. The cultivar diversity had a geographical component. We also noted major differentiation between early and late cultivars, with higher diversity in the early ones. Cultivars from northern Benin and early cultivars had the greatest allelic richness. SSR markers proved to be powerful tools for fingerprinting each cultivar and analysing their genetic relationships. The results of this study could be useful for defining a strategy for the conservation of genetic diversity in yams.


HortScience ◽  
2015 ◽  
Vol 50 (6) ◽  
pp. 797-800
Author(s):  
Xiaoli Wang ◽  
Zhiyong Wang ◽  
Li Liao ◽  
Xinyi Zhang ◽  
Changjun Bai

Carpetgrass [Axonopus compressus (Sw.) Beauv.] is an important warm-season perennial turfgrass that is widely used in tropical and subtropical areas. The genetic diversity of 63 carpetgrass accessions in China was studied using simple sequence repeat (SSR) markers. Fourteen SSR primer combinations generated a total of 49 distinct bands, 48 (97.96%) of which were polymorphic. The number of observed alleles ranged from 2 to 6, with an average of 3.5. Coefficients of genetic similarity among the accessions ranged from 0.24 to 0.98. Unweighted pair-group method with arithmetic means (UPGMA) clustered the 63 accessions into three groups, and not all samples from the same region belonged to the same group. SSR markers will promote marker-assisted breeding and the assessment of genetic diversity in wild germplasm resources of carpetgrass.


2009 ◽  
Vol 134 (3) ◽  
pp. 337-347 ◽  
Author(s):  
David Jesús Gil-Ariza ◽  
Iraida Amaya ◽  
José Manuel López-Aranda ◽  
José Federico Sánchez-Sevilla ◽  
Miguel Ángel Botella ◽  
...  

Unlike other important crops analyzed so far for genetic diversity and population structure, the brief history and particularities of the genetics of the cultivated strawberry (Fragaria ×ananassa Duchesne) have limited its genetic characterization. The genomic composition and the pattern of inheritance have not been fully elucidated, although a number of studies have suggested a highly diploidized genome. In this study, the similarity relationships and structure of 92 selected strawberry cultivars with widely diverse origins have been established using simple sequence repeat (SSR) markers derived from expressed sequence tags (EST-SSR markers). Genetic analysis performed by the unweighted pair group method with arithmetic mean clustering revealed a distribution according to both date of cultivar release and breeding for a specific climatic adaptation. Additionally, a model-based clustering approach identified three populations among the strawberry cultivars with an overall FST value of 0.15 to 0.16. Both analyses support a limited differentiation of modern cultivars, most probably as a consequence of the methodology of strawberry breeding. Interestingly, the collection of strawberry cultivars here analyzed showed comparable genetic differentiation to that observed in natural populations of Fragaria chiloensis (L.) Mill., one of its wild ancestors. Our results suggest that breeding has produced a small but significant reduction on the genetic diversity of F. ×ananassa. The panel of 10 EST-SSRs described in this work provided an extremely low probability of confusion (less than 10−11), offering an efficient and accurate method for cultivar identification.


2020 ◽  
Vol 17 (4) ◽  
pp. 156
Author(s):  
Surti Kurniasih ◽  
Rubiyo Rubiyo ◽  
Asep Setiawan ◽  
Agus Purwantara ◽  
Sudarsono Sudarsono

<p>Microsatellite or simple sequence repeat (SSR) markers have proven to be an excellent tool for cultivar identification, pedigree analysis, and genetic distance evaluations among organisms. The objectives of this research were to characterize cacao collection of Indonesian Coffee and Cacao Research Institute (ICCRI) and to analyze their genetic diversity using SSR markers. In this research, 39 SSR primer pairs were used to amplify genomic DNA of 29 cacao clones. Amplified SSR fragments for each primer pair were scored as individual band and used to determine genetic distance among evaluated cacao clones. Results of the experiment indicated that all SSR primer pairs evaluated were able to produce SSR markers for 29 cacao clones. The results also indicated that 34 out of 39 microsatellite loci evaluated were polymorphic, while 5 others were monomorphic. The total number of observed alleles among 29 clones was 132. Number of alleles per locus ranged from 4-8, with an average of 5.5 alelles per locus. Results of data analysis indicated that the PIC value was 0.665, the observed heterozigosity (Ho) was 0.651, and the gene diversity (He) was 0.720. The PIC, Ho, and He values were considered high. Genetic distances were evaluated using NTSys version 2.1 and dendrogram was constructed. Results of analysis indicated that 12 cacao clones evaluated were clustered in the first group with diversity coefficient of &lt; 3.75. Nine cacao clones were in the second group but with the same value of diversity coefficient (&lt;7.50). The rest of the cacao clones were in the third group with diversity coefficient of&gt;7.50. Based on those finding, all SSR primer pairs evaluated could be used to analyze cacao genome and be useful for genetic diversity analysis of cacao germplasm. The SSR marker analysis in ICCRI cacao collections resulted in high PIC, high observed heterozygosity, and high genetic diversity.</p><p>Key words: Theobroma cacao L, microsatelite, molecular marker, genetic diversity, heterozygosity</p><p> </p><p><strong>Abstrak</strong></p><p>Marka mikrosatelit atau sekuens sederhana berulang (simple sequence repeat = SSR) terbukti merupakan alat yang bagus untuk identifikasi kultivar, analisis pedigree, dan evaluasi jarak genetik berbagai organisme. Penelitian ini bertujuan untuk:1) karakterisasi kakao koleksi Pusat penelitian Kopi dan Kakao Indonesia menggunakan marka SSR dan 2) analisis keragaman genetik klon-klon kakao koleksi dengan menggunakan marka SSR. Dalam penelitian ini, 39 pasangan primer SSR telah digunakan untuk amplifikasi DNA genomik dari 29 klon kakao. Skoring pita SSR hasil amplifikasi menggunakan masing-masing pasangan primer dilakukan secara terpisah dan digunakan untuk menentukan jarak genetik di antara klon kakao yang dievaluasi. Hasil percobaan menunjukkan bahwa semua pasangan primer SSR yang digunakan mampu menghasilkan pita DNA hasil amplifikasi (marka SSR) untuk 29 klon kakao yang diuji. Hasil penelitian juga menunjukkan bahwa 34 dari 39 lokus SSR yang dianalisis bersifat polimorfik sedangkan lima primer yang lain bersifat monomorfik. Dari 29 klon kakao yang dievaluasi, telah berhasil diamplifikasi sebanyak 132 alel, dengan kisaran antara 4-8 alel/lokus. Rataan jumlah alel per lokus sebanyak 5,50. Hasil analisis data yang dilakukan juga menunjukkan nilai PIC untuk marka SSR yang digunakan sebesar 0,665. Untuk populasi klon kakao yang dievaluasi, diperoleh nilai rataan heterosigositas pengamatan (Ho) sebesar 0,651 dan rataan diversitas gen (He) sebesar 0,720. Nilai PIC Ho dan He yang didapat tergolong tinggi. Berdasarkan analisis keragaman dengan menggunakan program NTSys, diperoleh hasil 12 klon kakao berada dalam grup pertama (koefisien keragaman&lt;3,75) dan9 klon berada dalam grup kedua, dengan koefisien keragaman &lt; 7,50. Sedangkan klon-klon lainnya mempunyai koefisien keragaman &gt; 7,50. Berdasarkan hasil penelitian dan analisis data disimpulkan bahwa marka SSR dapat digunakan untuk menganalisis keragaman genetik plasma nutfah kakao. Tingkat polimorfisme yang dihasilkan marka SSR relatif tinggi. Tingkat heterosigositas plasma nutfah kakao koleksi Puslit Kopi dan Kakao Indonesiarelatif tinggi, dan keragaman genetiknyacukup tinggi.</p><p>Kata kunci : Theobroma cacao L, mikrosatelit, marka molekuler, keragaman genetik, heterosigositas</p>


2015 ◽  
Vol 22 (2) ◽  
pp. 67-75 ◽  
Author(s):  
Leila Samiei ◽  
Mahnaz Kiani ◽  
Homa Zarghami ◽  
Farshid Memariani ◽  
Mohammad Reza Joharchi

In this study genetic diversity and interspecific relationships of 11 Allium L. species from Khorassan province of Iran including 32 accessions were investigated by inter simple sequence repeat (ISSR) markers. Nine ISSR primers produced a total of 80 polymorphic markers and revealed high polymorphism among the studied species. The average gene diversity, effective number of alleles and Shannon’s information index were 0.2, 1.28 and 0.3, respectively. Allium kuhsorkhense exhibited the greatest level of variation (He: 0.18), whereas A. stipitatum demonstrated the lowest level of variability (He: 0.05). UPGMA (Unweighted Pair Group Method with Arithmetic mean) analysis showed that Allium accessions have a similarity range of 0.60 to 0.95. Allium scapriscapum composed the most distant group in the dendrogram. The clustered groups of Allium species clearly reflect the recent taxonomic concept of the genus at the subgenus and section levels. The present study showed that the ISSR technique is an effective molecular approach for analyzing genetic diversity and relationship in Allium species.Bangladesh J. Plant Taxon. 22(2): 67-75, 2015 (December)


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