scholarly journals SSR allelic diversity in relation to morphological traits and resistance to grain mould in sorghum

2010 ◽  
Vol 61 (3) ◽  
pp. 230 ◽  
Author(s):  
Rajan Sharma ◽  
S. P. Deshpande ◽  
S. Senthilvel ◽  
V. P. Rao ◽  
V. Rajaram ◽  
...  

Allelic variation at 46 simple sequence repeat (SSR) marker loci well distributed across the sorghum genome was used to assess genetic diversity among 92 sorghum lines, 74 resistant and 18 susceptible to grain mould. Of the 46 SSR markers, 44 were polymorphic, with the number of alleles ranging from 2 to 20 with an average of 7.55 alleles per locus. Genetic diversity among the sorghum lines was high as indicated by polymorphic information content (PIC) and gene diversity values. PIC values of polymorphic SSR markers ranged from 0.16 to 0.90, with an average of 0.54. Gene diversity among the sorghum lines varied from 0.16 to 0.91, with an average score of 0.58 per SSR marker. AMOVA indicated that 12% of the total variation observed among the sorghum lines was accounted for between grain mould resistant and susceptible types. Diversity based on six morphological traits and grain mould scores indicated major roles of panicle type and glumes coverage, followed by grain colour, in clustering of the lines. Seven grain mould resistant/susceptible pairs with dissimilarity indices >0.50, but with similar flowering time, plant height, and panicle type/inflorescence within each pair, were selected for use in developing recombinant inbred line mapping populations to identify genomic regions (and quantitative trait loci) associated with sorghum grain mould resistance.

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Nor Asiah Ismail ◽  
M. Y. Rafii ◽  
T. M. M. Mahmud ◽  
M. M. Hanafi ◽  
Gous Miah

Fifty-seven accessions of torch ginger (Etlingera elatior) collected from seven states in Peninsular Malaysia were evaluated for their molecular characteristics using ISSR and SSR markers to assess the pattern of genetic diversity and association among the characteristics. Diversity study through molecular characterization showed that high variability existed among the 57 torch ginger accessions. ISSR and SSR molecular markers revealed the presence of high genetic variability among the torch ginger accessions. The combination of different molecular markers offered reliable and convincing information about the genetic diversity of torch ginger germplasm. This study found that SSR marker was more informative compared to ISSR marker in determination of gene diversity, polymorphic information content (PIC), and heterozygosity in this population. SSR also revealed high ability in evaluating diversity levels, genetic structure, and relationships of torch ginger due to their codominance and rich allelic diversity. High level of genetic diversity discovered by SSR markers showed the effectiveness of this marker to detect the polymorphism in this germplasm collection.


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>


2012 ◽  
Vol 37 (3) ◽  
pp. 389-398 ◽  
Author(s):  
S Islam ◽  
MS Haque ◽  
RM Emon ◽  
MM Islam ◽  
SN Begum

A study was undertaken to examine the genetic diversity of 12 wheat (Triticum aestivum L.) genotypes, using 4 simple sequence repeats (SSRs). A total of 10 alleles were found. Allele number per locus ranged from 2 to 4 with an average of 2.5. The polymorphic information content (PIC) values ranged from 0.2755 to 0.5411 with an average of 0.3839. The average gene diversity over all SSR loci for the 12 wheat genotypes was 0.4688, ranging from 0.3299 to 0.6042. Cluster analysis based on microsatellite allelic diversity discriminated the varieties into different clusters. Genetic diversity was the highest between variety Gourab and Akbar as well as Gourab and BAW-1064, showing a genetic distance value of 0.4697. The genetic distance was lowest between Balaka and Aghrani as well as Triticale and BAW-1036. Positive correlations were found between gene diversity, number of alleles, the allele size range and the types of repeat motif of microsatellite markers. It was found from this study that microsatellite markers could characterize and discriminate all of the genotypes. More primers should be used for saturation of different regions in further studies. Bangladesh J. Agril. Res. 37(3): 389-398, September 2012 DOI: http://dx.doi.org/10.3329/bjar.v37i3.12082


2005 ◽  
Vol 56 (7) ◽  
pp. 691 ◽  
Author(s):  
B. J. Stodart ◽  
M. Mackay ◽  
H. Raman

A set of 44 bread wheat landraces was used to determine the efficacy of 16 amplifed fragment length polymorphism (AFLP) primers and 63 wheat simple sequence repeat (SSR) markers in identifying polymorphisms between accessions. The SSR markers detected approximately 10 alleles per locus with a mean gene diversity (Hz) of 0.63, whereas AFLP primers identified approximately 147 fragments per primer with a mean gene diversity of 0.25. A set of 54 SSR markers and 11 AFLP primers was identified as highly polymorphic (polymorphic information content (PIC) ≥ 0.5 and 0.3 for SSR and AFLP, respectively), and suitable for molecular characterisation of germplasm. Principle coordinate analysis suggested that the AFLP and SSR loci could be used to discriminate among accessions collected from North Africa and southern Europe from those collected from the Middle East. Both marker types indicate that accessions from North Africa and southern Europe, the Middle East, and southern and eastern Asia are genetically diverse. The results indicate the usefulness of the molecular markers to assess genetic diversity present within germplasm collections.


Author(s):  
Maizura Abu Sin ◽  
Ghizan Saleh ◽  
Nur Ashikin Psyquay Abdullah ◽  
Pedram Kashiani

Genetic diversity and phenotypic superiority are important attributes of parental inbred lines for use in hybrid breeding programs. In this study, genetic diversity among 30 maize (Zea mays L.) inbred lines comprising of 28 introductions from the International Maize and Wheat Improvement Center (CIMMYT), one from Indonesia and a locally developed, were evaluated using 100 simple sequence repeat (SSR) markers, as early screening for potential parents of hybrid varieties. All markers were polymorphic, with a total of 550 unique alleles detected on the 100 loci from the 30 inbred lines. Allelic richness ranged from 2 to 13 per locus, with an average of 5.50 alleles (na). Number of effective alleles (ne) was 3.75 per locus, indicating their high effectiveness in revealing diversity among inbred lines. Average polymorphic information content (PIC) was 0.624, with values ranging from 0.178 to 0.874, indicating high informativeness of the markers. High gene diversity was observed on Chromosomes 8 and 4, with high number of effective alleles, indicating their potential usefulness for QTL analysis. The UPGMA dendrogram constructed identified four heterotic groups within a similarity index of 0.350, indicating that these markers were able to group the inbred lines. The three-dimensional PCoA plot also supports the dendrogram grouping, indicating that these two methods complement each other. Inbred lines in different heterotic groups have originated from different backgrounds and population sources. Information on genetic diversity among the maize inbred lines are useful in developing strategies exploiting heterosis in breeding programs


Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 68 ◽  
Author(s):  
Kyung Jun Lee ◽  
Jung-Ro Lee ◽  
Raveendar Sebastin ◽  
Gyu-Taek Cho ◽  
Do Yoon Hyun

Ginseng (Panax ginseng C.A. Meyer), commonly known as Korean or Asian ginseng, is a perennial herb native to Korea and China. There has been limited research effort to analyze the genetic diversity and population structure of ginseng germplasm because of its growth habits. In the present study, genetic diversity and population structure of ginseng germplasm conserved in the National Agrobiodiversity Center (NAC) of South Korea were analyzed to provide basic data for future preservation and breeding of ginseng genetic resources. Seventeen simple sequence repeat (SSR) markers were used to assess the genetic diversity and population structure of 1109 ginseng accessions. Among 1109 ginseng accessions, 1042 (94.0%) accessions were landraces and 66 (6.0%) accessions were breeding lines (61 accessions, 5.5%) or cultivars (5 accessions, 0.5%). SSR markers revealed 56 different alleles with an average of 3.29 alleles per locus. The average gene diversity was 0.49. Analysis of molecular variance showed that 91% of allelic diversity was attributed to individual accessions within clusters while only 9% was distributed among clusters. Using discriminant analysis of principal components, 12 clusters were detected in 1109 ginseng accessions. The results of this study provide molecular evidence for the narrow genetic base of ginseng germplasm in NAC. For the broad understanding and efficient use of ginseng germplasm, it is necessary to analyze functional factors and to evaluate morphological traits.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Saba Jasim Aljumaili ◽  
M. Y. Rafii ◽  
M. A. Latif ◽  
Siti Zaharah Sakimin ◽  
Ibrahim Wasiu Arolu ◽  
...  

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon’s information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He) of 0.60 and mean Nei’s gene diversity index of 0.36. The dendrogram based on UPGMA and Nei’s genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.


2018 ◽  
Vol 15 (1) ◽  
pp. 181-186
Author(s):  
Anju Bajpai ◽  
Nimisha Sharma ◽  
Navin Srivastava ◽  
Shailendra Rajan ◽  
Muthukumar. M

Appreciable intra cultivar variation has warranted clonal selections, which has emerged as an important tool in mango breeding. This important source of morphological variability manifested in altered fruit and quality attributes has yielded improved clones in India and abroad, few of which were exposed to SSR based analysis. Statistical parameters viz., Polymorphic Information Content (0.319 in MiIIHR12 to 0.819 for MiIIHR26) and Gene Diversity (0.399 in MiIIHR12 to 0.839 for MiIIHR26), defined the ability of the chosen SSR markers to discriminate the intra cultivar variability, besides highlighting the extent of diversity captured by the improved clones. Furthermore, genetic relationship among the clones derived by Wards minimum variance, placed Himsagar and Langra clones in Cluster I and II respectively, Himsagar recording high genetic heterogeneity within its cluster, intra cultivar variability being 0.16-0.916, thus showing suitability for breeding by clonal selections. Even the use of limited SSR marker loci (6), could reveal and document the genomic variations accounting for the variations in the Dashehari clones as well as placing land race ‘Suraiyya’, as an out-group. The sampled clones of elite variety Chausa did not show any variation at the studied marker loci, thus exposing limited heterogeneity in the clones and demanding more explorations for breeding superior types targeting regularity in bearing.


Genetika ◽  
2015 ◽  
Vol 47 (3) ◽  
pp. 983-992
Author(s):  
Zelmíra Balázová ◽  
Andrej Trebichalský ◽  
Zdenka Gálová ◽  
Radomíra Hornyák-Gregáňová

Present study aims to testify usefulness of particular wheat SSR markers for the detection of genetic diversity degree in the set of 59 triticale cultivars and new lines coming from different European countries and USA. For this purpose, a set of fifteen SSR markers were used. One SSR marker (Xwmc429) gave a uniform spectrum. The set of fourteen polymorphic markers provided 94 alleles with an average frequency of 6.71 alleles per locus. The number of alleles ranged between 2 (Xbarc 195) and 10 (Xbarc 137). Resulting from the number and frequency of alleles, diversity index (DI), polymorphic information content (PIC) and probabilities of identity (PI) were calculated. An average value of PIC for 14 markers was 0.640, the highest value was calculated for wheat SSR marker Xgwm 46 (0.809). Based on UPGMA algorithm, a dendrogram was constructed. It was able to separate 57 of 59 cultivars (96,6 %) from each other. American new-line NE-422T significantly separated from all cultivars and new lines. Only two french cultivars Bienvenu and Wilfried had not been separated from each other. A tested set of SSR markers allowed to better understand genetic relationships among European cultivars and American new lines. In general, a dendrogram along with results of calculated genetic indicators such as PIC, PI and DI point out at SSRs markers as high informative and usefull tool in genetic diversity research between close-related species.


Genome ◽  
2008 ◽  
Vol 51 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Zvi Peleg ◽  
Tzion Fahima ◽  
Shahal Abbo ◽  
Tamar Krugman ◽  
Yehoshua Saranga

Simple sequence repeat (SSR) markers have become a major tool in population genetic analyses. The anonymous genomic SSRs (gSSRs) have been recently supplemented with expressed sequence tag (EST) derived SSRs (eSSRs), which represent the transcribed regions of the genome. In the present study, we used 8 populations of wild emmer wheat ( Triticum turgidum subsp. dicoccoides ) to compare the usefulness of the two types of SSR markers in assessing allelic diversity and population structure. gSSRs revealed significantly higher diversity than eSSRs in terms of average number of alleles (14.92 vs. 7.4, respectively), polymorphic information content (0.87 vs. 0.68, respectively), and gene diversity (He; 0.55 vs. 0.38, respectively). Despite the overall differences in the level of diversity, Mantel tests for correlations between eSSR and gSSR pairwise genetic distances were found to be significant for each population as well as for all accessions jointly (RM = 0.54, p = 0.01). Various genetic structure analyses (AMOVA, PCoA, STRUCTURE, unrooted UPGMA tree) revealed a better capacity of eSSRs to distinguish between populations, while gSSRs showed a higher proportion of intrapopulation (among accessions) diversity. We conclude that eSSR and gSSR markers should be employed in conjunction to obtain a high inter- and intra-specific (or inter- and intra-varietal) distinctness.


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