scholarly journals An Improved Method for Assessing Simple Sequence Repeat (SSR) Variation in Echinochloa crus-galli (L.) P. Beauv (Barnyardgrass)

Diversity ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 3
Author(s):  
Carlo Maria Cusaro ◽  
Carolina Grazioli ◽  
Francesco Zambuto ◽  
Enrica Capelli ◽  
Maura Brusoni

Echinochloa crus-galli (L.) P. Beauv. (barnyardgrass) is one of the most noxious weeds infesting Italian rice fields. It is characterized by high genetic intraspecific variability and has developed resistance to several classes of herbicides. The aim of our study was to assess, for the first time in Italy, the genetic diversity in E. crus-galli from differently managed rice fields in the Lombardy region (Northern Italy) using eight specific SSR markers. To this purpose, an amplification protocol was optimized, testing different DNA concentrations, PCR mixtures, and temperatures. A total of 48 alleles were identified in 144 samples. SSR fingerprint analysis using R 3.6.3 software (poppr, polysat, and StAMPP) allowed us to handle SSRs as codominant and polyploid data. The results suggested that genetic richness and diversity were high. The analysis of molecular variance (AMOVA) indicated that genetic variation exists mainly between agronomic managements (47.23%) and among populations (37.01%). Hierarchical clustering and PCoA were in concordance with the identification of four distinct genetic groups. Our results confirm that SSR markers represent a valuable and affordable tool for the assessment of E. crus-galli genetic diversity and would grant useful information to plan more targeted, effective, and sustainable control strategies against barnyardgrass. The improved methodology applied here allowed us to assess the genetic variability of an allo-hexaploid species without information loss and biased results.

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.


2005 ◽  
Vol 3 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Sally L. Dillon ◽  
Peter K. Lawrence ◽  
Robert J. Henry

The Sorghum genus is extremely diverse both morphologically and geographically, however, relatively few of the 25 recognized species have been evaluated genetically. The apparent lack of basic knowledge pertaining to the levels of genetic diversity both within and between the 17 Australian wild species is a major obstacle to both their effective conservation and potential use in breeding programmes. Twelve Sorghum bicolor-derived simple sequence repeat (SSR) markers were evaluated for cross-species amplification in all 25 Sorghum species. The SSR markers were highly polymorphic, with diversity indices ranging from 0.59 to 0.99 with mean of 0.91. Five markers combined were able to differentiate 24 of the 25 Sorghum species, with intra-species polymorphism apparent. Sorghum bicolor-derived SSRs have proven to be an efficient source of markers for genetic diversity studies of the relatively poorly characterized Australian indigenous Sorghum species.


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>


Author(s):  
Shyryn Almerekova ◽  
Nasima Favarisova ◽  
Yerlan Turuspekov ◽  
Saule Abugalieva

Abstract Salsola arbuscula Pall., Salsola arbusculiformis Drob. and Salsola chiwensis M. Pop. have great environmental importance as they can stabilise sand dunes and therefore are useful for desert zone landscaping. The genetic diversity and phylogenetic relationships of populations of these species collected in Western Kazakhstan were analysed using internal transcribed spacers (ITS) and simple sequence repeat (SSR) markers. The ITS sequences of species were aligned with sequences of 37 Salsola species from the NCBI. ITS analysis clustered the samples into two major groups and eight sections. The phylogenetic tree and haplotype network relationships confirmed the polyphyletic origin of Salsola and allowed taxonomic reassessment for the studied species. A set of SSR markers originally developed from genera Agriophyllum, Haloxylon, and Beta was tested for their variability in Salsola species. Twenty-six tested SSR markers were selected for their transferability scores, and 13 of them were suitable for study of genetic diversity in populations of three Salsola species. It was concluded that polymorphic SSR markers were efficient in the separation of the studied Salsola species and could be effectively used in studies related to the genetic variation in the genus.


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.


Author(s):  
Manish Kapoor ◽  
Pooja Mawal ◽  
Vikas Sharma ◽  
Raghbir Chand Gupta

Abstract Background Various Asparagus species constitute the significant vegetable and medicinal genetic resource throughout the world. Asparagus species serve as important commodity of food and pharmaceutical industries in India. A diverse collection of Asparagus species from different localities of Northwest India was investigated for its genetic diversity using simple sequence repeat (SSR) markers. Results Polymorphic SSR markers revealed high genetic diversity. Primer SSR-15 amplified maximum of 8 fragments while 3 primers, namely, SSR-43, SSR-63, and AGA1 amplified minimum of 3 fragments. Collectively, 122 alleles were amplified in a range between 3 and 8 with an average of 5 alleles per marker. The size of the amplified alleles ranged between 90 and 680 base pairs. Polymorphism information content (PIC) value varied from a highest value of 0.499 in primer AGA1 to a lowest value of 0.231 in primer SSR-63 with a mean value of 0.376 showing considerable SSR polymorphism. Dendrogram developed on the basis of Jaccard’s similarity coefficient and neighbor-joining tree segregated all the studied Asparagus species into two discrete groups. Structure analysis based on Bayesian clustering allocated different accessions to two independent clusters and exhibited low level of individual admixture. Conclusions The genetic diversity analysis showed a conservative genetic background for maximum species of asparagus. Only Accessions of Asparagus adscendens were split into two diverse clusters suggesting a wide genetic base of this species as compared to other species. Overall genetic diversity was high, and this germplasm of Asparagus can be used in future improvement programs. The findings of current research on Asparagus germplasm can make a momentous contribution to initiatives of interbreeding, conservation, and improvement of Asparagus in future.


HortScience ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 283-287
Author(s):  
Xiu Cai Fan ◽  
Hai Sheng Sun ◽  
Ying Zhang ◽  
Jian Fu Jiang ◽  
Min Li ◽  
...  

In this study, simple sequence repeat (SSR) and sequence-related amplified polymorphism (SRAP) markers were used to analyze the genetic diversity of 48 wild Vitis davidii accessions. A total of 78 distinct alleles were amplified by 11 SSR primers, and the average allele number was 8.8. The average observed heterozygosity (Ho) and expected heterozygosity (He) values were 0.785 and 0.814, respectively. The effective allele numbers ranged from 3.92 to 9.61. The average polymorphism information content (PIC) was 0.798. Twelve of 169 SRAP primer combinations were selected for SRAP analysis. A total of 188 bands were produced, and the average was 15.7 bands per primer combination; the average percentage of polymorphic bands was 84.0%. The average PIC was 0.76. The results of the clustering analysis based on SSR markers showed that the 48 wild V. davidii accessions could be classified into five main clusters and had a genetic similarity coefficient level of 0.68. The dendrogram obtained from the SRAP data showed that 48 wild V. davidii accessions could be classified into five main clusters and had a genetic similarity coefficient of 0.72. SSR and SRAP markers differentiated all accessions studied including those with a similar pedigree. We speculated on the origin of Ciputao 0941♀, Ciputao 0940♂, and Fu’an-ci-01 using SSR markers and used both SSR and SRAP markers to resolve homonymy. The result will be valuable for further management and protection of V. davidii germplasm resources.


2016 ◽  
Vol 8 (3) ◽  
pp. 380-385 ◽  
Author(s):  
Aissam EL FINTI ◽  
Driss TALIBI ◽  
Mouhamed SIDKI ◽  
Abdelhamid E. MOUSADIK

Estimation of genetic parameters at SSR loci can be applied for assessing the differences between cultivars or populations, either for variety distinction or the management of genetic resources. In this study, 13 Opuntia ficus-indica cultivars were analyzed using 10 SSR markers selected for studying the genetic diversity among these chosen cultivars. Over the 10 SSR markers, a total of 45 reproducible bands were scored with an average of 4.5 alleles/locus, while the observed heterozygosity (Ho) values of amplified loci ranged from 0.15 (SSR1) to 0.92 (SSR2 and SSR 11). Genetic distance analysis of the 13 cultivars showed a large genetic differentiation (GST = 0.47) and high number of different groups. Most of the accessions were not found to be clustered according to their eco-geographical origin. In addition, each cultivar was characterized by its own multiallelic combination between loci. The results revealed the usefulness of SSR in understanding of genetic diversity in Moroccans Barbary fig cultivars, thus being helpful to set up rational decisions concerning the establishment of a national reference collection.


HortScience ◽  
2015 ◽  
Vol 50 (8) ◽  
pp. 1143-1147 ◽  
Author(s):  
Benard Yada ◽  
Gina Brown-Guedira ◽  
Agnes Alajo ◽  
Gorrettie N. Ssemakula ◽  
Robert O.M. Mwanga ◽  
...  

Genetic diversity is critical in sweetpotato improvement as it is the source of genes for desired genetic gains. Knowledge of the level of genetic diversity in a segregating family contributes to our understanding of the genetic diversity present in crosses and helps breeders to make selections for population improvement and cultivar release. Simple sequence repeat (SSR) markers have become widely used markers for diversity and linkage analysis in plants. In this study, we screened 405 sweetpotato SSR markers for polymorphism on the parents and progeny of a biparental cross of New Kawogo × Beauregard cultivars. Thereafter, we used the informative markers to analyze the diversity in this population. A total of 250 markers were polymorphic on the parents and selected progeny; of these, 133 were informative and used for diversity analysis. The polymorphic information content (PIC) values of the 133 markers ranged from 0.1 to 0.9 with an average of 0.7, an indication of high level of informativeness. The pairwise genetic distances among the progeny and parents ranged from 0.2 to 0.9, and they were grouped into five main clusters. The 133 SSR primers were informative and are recommended for use in sweetpotato diversity and linkage analysis.


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