Genome-wide identification of SSR markers in the Brassica A genome and their utility in breeding

2016 ◽  
Vol 96 (5) ◽  
pp. 808-818 ◽  
Author(s):  
Neil Hobson ◽  
Habibur Rahman

Simple sequence repeat (SSR) markers can be applied to genotyping projects at low cost with inexpensive equipment. The objective of this study was to develop SSR markers from the publically-available genome sequence of Brassica rapa and provide the physical position of these markers on the chromosomes for use in breeding and research. To assess the utility of these new markers, a subset of 60 markers were used to genotype 43 accessions of B. rapa. Fifty-five markers from the 10 chromosome scaffolds produced a total of 730 amplicons, which were then used to perform a phylogenetic analysis of the accessions, illustrating their utility in distinguishing between a wide range of germplasm. In agreement with similar studies of genetic diversity, our markers separated accessions into distinct genetic pools including Chinese cabbage, Chinese winter oilseed, European winter oilseed, Canadian spring oilseed, pak-choi, turnip, and yellow sarson. The results further illustrate the presence of a high level of genetic diversity in B. rapa, and demonstrate the potential of these SSR markers for use in breeding and research.

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.


2021 ◽  
Author(s):  
Bhawna Bonthala ◽  
Manjusha Verma ◽  
M Z Abdin ◽  
Lalit Arya ◽  
Chithra D Pandey ◽  
...  

Abstract Lagenaria siceraria (Molina) Standley is an important cultivated crop with its immense importance in pharmaceutical industry and as vegetable. Its seed, root, stem, leaves, flower and fruit are used as an ointment for ailment of various diseases throughout Asia. Despite its worldwide importance,informative co-dominant microsatellite markers in the bottle gourd crop are very restricted, impeding geneticimprovement, cultivar identification and phylogenetic studies. Next generation sequencing has revolutionizedthe approaches for discovery, assessment and validation of molecular markers. We conducted a genome wideanalysis, for developing SSR markers by utilizing restriction site-associated DNA sequencing (RAD-Seq) data.By performing in silico mining of microsatellite repeat-motifs, we developed 45,066 perfect SSR markers. Ofwhich 203 markers were successfully validated and 101 (49.75%) polymorphic primer pairs were utilized for anin depth genetic diversity and population structure analysis of 96 accessions from the National Genebank ofIndia. Tetranucleotide repeats (∼34.3%) were the most prevalent followed by trinucleotide repeats (∼30.73%),further 21.03%, 9.6% and 4.3% of di-, penta- and hexa- nucleotide repeats in the bottle gourd genome. Syntenyof SSR markers on 11 bottle gourd linkage groups was correlated with the 7 chromosomes of cucumber(93.2%), 12 chromosomes of melon (87.4%) and 11 watermelon (90.8%). The generated SSR markers providea valuable tool for germplasm characterization, genetic linkage map construction, studying synteny, genediscovery and for breeding in bottle gourd and other cucurbits species.


2021 ◽  
pp. 1-10
Author(s):  
Veluru Bhargav ◽  
Rajiv Kumar ◽  
Anuradha Sane ◽  
T. Manjunatha Rao ◽  
T. Usha Bharathi ◽  
...  

Abstract Understanding genetic diversity in target populations is of great importance in breeding and a prerequisite for association mapping of traits. In this study, 57 cross species simple sequence repeat (SSR) markers were screened for amplification in China aster. Twenty six polymorphic markers were used to estimate the genetic diversity in forty two China aster genotypes. The observed and expected heterozygosities within the genotypes were ranged from 0.00 to 0.80 and 0.17 to 0.50, respectively. Weighted Neighbor Joining method, grouped China aster genotypes into five major clusters which coincided for morphological traits mostly flower color and form, but not correlated for their geographical locations. The results suggested that, population may be useful for the genome-wide marker–trait association mapping. These set of cross species transferable SSR markers would enable the application of the SSR technique in China aster crop improvement.


2020 ◽  
Author(s):  
Lei Zhu ◽  
Hua yu Zhu ◽  
Yan man Li ◽  
Xiang bin Wu ◽  
Jin tao Li ◽  
...  

Abstract Background The Cucurbita genus contains important economic crops in the world, while limited molecular markers have been developed in the past years. Simple sequence repeats (SSR) markers are powerful tools for the study of genetic mapping construction, genetic diversity analysis and genome wide association. The availability of pumpkin genome information has made it possible to analyze SSRs in genome wide across three Cucurbita species. Results In this paper, based on the whole genome sequences, 34,375 SSR loci were found in C. moschata, 30,577 SSR loci were found in C. maxima and 38,104 SSR loci were found in C. pepo. C. pepo has the maximum density of SSRs with an average of 145 SSR/Mb. In general, the frequency in total SSR loci decreased with the increase of the motif length, dinucleotide motifs were the most common motifs in the three species, and for the same repeat types, the SSR frequency decreased sharply with the increase of the repeat number. Most of those SSR loci were suitable for marker development (84.75% in C. moscata, 94.53% in C. maxima and 95.09% in C. pepo). Based on those markers, we compared and analyzed the cross-species SSR markers between C. pepo and other Cucurbitaceae species by silico-PCR. Using these cross-species primers, the high collinear relationships between C. pepo and the other two species were detected, respectively. Furthermore, the application of SSR markers in genetic diversity analysis was tested in C. pepo, the results showed that they were good tools to be used in genetic diversity analysis. Conclusion In this study, the genome wide SSR markers were detected from three Cucurbita species, and some of their applications were proved by comparative genomics and genetic diversity analysis. The large number of genome-wide SSR markers and crossspecies markers would promote the basic and applied studies of Cucurbita species, such as gene mapping, QTLs mapping, comparative genomics and marker-assisted breeding.


2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110355
Author(s):  
Hai-feng Tian ◽  
Qiao-mu Hu ◽  
Zhong Li

Objectives: Swamp eel is one model species for sexual reversion and an aquaculture fish in China. One local strain with deep yellow and big spots of Monopterus albus has been selected for consecutive selective breeding. The objectives of this study were characterizing the Simple Sequence Repeats (SSRs) of M. albus in the assembled genome obtained recently, and developing polymorphic SSRs for future breeding programs. Methods: The genome wide SSRs were mined by using MISA software, and their types and genomic distribution patterns were investigated. Based on the available flanking sequences, primer pairs were batched developed, and Polymorphic SSRs were identified by using Polymorphic SSR Retrieval tool. The obtained polymorphic SSRs were validated by using e-PCR and capillary electrophoresis, then they were used to investigate genetic diversity of one breeding population. Results: A total of 364,802 SSRs were identified in assembled M. albus genome. The total length, density and frequency of SSRs were 8,204,641 bp, 10,259 bp/Mb, and 456.16 loci/Mb, respectively. Mononucleotide repeats were predominant among SSRs (33.33%), and AC and AAT repeats were the most abundant di- and tri-nucleotide repeats motifs. A total of 287,189 primer pairs were designed, and a high-density physical map was constructed (359.11 markers per Mb). A total of 871 polymorphic SSRs were identified, and 38 SSRs of 101 randomly selected ones were validated by using e-PCR and capillary electrophoresis. Using these 38 polymorphic SSRs, 201 alleles were detected and genetic diversity level (Na, PIC, HO, and He) was evaluated. Conclusions: The genome-wide SSRs and newly developed SSR markers will provide a useful tool for genetic mapping, diversity analysis studies in swamp eel in the future. The high level of genetic diversity (Na = 5.29, PIC = 0.5068, HO = 0.4665, He = 0.5525) but excess of homozygotes ( FIS = 0.155) in one breeding population provide baseline information for future breeding program.


Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1748
Author(s):  
Brenda I. Guerrero ◽  
M. Engracia Guerra ◽  
Sara Herrera ◽  
Patricia Irisarri ◽  
Ana Pina ◽  
...  

Japanese plum (Prunus salicina Lindl.) is widely distributed in temperate zones across the world. Since its introduction to USA in the late 19th century, this species has been hybridized with up to 15 different diploid Prunus species. This high level of introgression has resulted in a wide range of traits and agronomic behaviors among currently grown cultivars. In this work, 161 Japanese plum-type accessions were genotyped using a set of eight Simple Sequence Repeats (SSR) markers to assess the current genetic diversity and population structure. A total of 104 alleles were detected, with an average of 13 alleles per locus. The overall Polymorphic Informative Content (PIC) value of SSR markers was 0.75, which indicates that these SSR markers are highly polymorphic. The Unweighted Pair Group Method with Arithmetic (UPGMA) dendrogram and the seven groups inferred by Discriminant Analysis of Principal Components (DAPC) revealed a strong correlation of the population structure to the parentage background of the accessions, supported by a moderate but highly significant genetic differentiation. The results reported herein provide useful information for breeders and for the preservation of germplasm resources.


2018 ◽  
Vol 69 (9) ◽  
pp. 904 ◽  
Author(s):  
Siwar Bouabid ◽  
H. Chennaoui Kourda ◽  
A. Boussaha ◽  
M. Ben Naceur ◽  
A. Zoghlami Khélil

Narbon vetch (Vicia narbonensis L.) is a promising forage legume with good resistance to cold and drought. The assessment of genetic diversity of Narbon vetch is an essential component in germplasm management. In this study, we analysed the genetic diversity of 13 local and introduced Narbon vetch accessions from three continents using 27 morphological traits and 13 simple sequence repeat (SSR) markers. Significant differences among accessions for morphological and phenological traits were observed. The SSR markers showed a total of 126 alleles with a mean number of two alleles per locus. Polymorphic information content values were in the range of 0.772–0.915 with an average of 0.858. A high level of diversity (Nei’s genetic differentiation index of 59) was observed among accessions. Analysis of genetic distances separated the studied accessions into three groups based on both morphological and SSR markers. Cluster analysis of the SSR markers separated the accessions into three groups according to geographical origin. The Tunisian populations shared the same morphological traits but differed genetically from each other and were similar to those from Lebanon. A significant correlation was detected between morphological traits and SSR markers. The results suggested that SSR markers can be used to efficiently distinguish Narbon vetch accessions and estimate their genetic diversity.


2017 ◽  
Vol 17 (1) ◽  
pp. 17 ◽  
Author(s):  
Nur Kholilatul Izzah ◽  
Reflinur Reflinur ◽  
Tae-Jin Yang

<p>Development of Expressed Sequence Tag-Simple Sequence Repeat (EST-SSR) markers derived from public database is known to be more efficient, faster and low cost. The objective of this study was to generate a new set of EST-SSR markers for broccoli and its related species and their usefulness for assessing their genetic diversity. A total of 202 Brassica oleracea ESTs were retrieved from NCBI and then assembled into 172 unigenes by means of CAP3 program. Identification of SSRs was carried out using web-based tool, RepeatMasker software. Afterwards, EST-SSR markers were developed using Primer3 program. Among the identified SSRs, trinucleotide repeats were the most common repeat types, which accounted for about 50%. A total of eight primer pairs were successfully designed and yielded amplification products. Among them, five markers were polymorphic and displayed a total of 30 alleles with an average number of six alleles per locus. The polymorphic markers were subsequently used for analyzing genetic diversity of 36 B. oleracea cultivars including 22 broccoli, five cauliflower and nine kohlrabi cultivars based on genetic similarity matrix as implemented in NTSYS program. At similarity coefficient of 61%, a UPGMA clustering dendrogram effectively separated 36 genotypes into three main groups, where 30 out of 36 genotypes were clearly discriminated. The result obtained in the present study would help breeders in selecting parental lines for crossing. Moreover, the novel EST-SSR markers developed in the study could be a valuable tool for differentiating cultivars of broccoli and related species.</p>


Crustaceana ◽  
2021 ◽  
Vol 94 (2) ◽  
pp. 189-205
Author(s):  
Junxiao Sun ◽  
Guohui Peng ◽  
Lijing Xiong ◽  
Cong Tan ◽  
Yanhe Li ◽  
...  

Abstract The red swamp crayfish, Procambarus clarkii (Girard, 1852), is currently an economically important aquaculture animal. Its genetic basis has been scarcely reported, however, partly due to the absence of abundant molecular markers in the genome. In this study, Simple Sequence Repeat (SSR) loci were mined, based on genome survey sequencing via the next generation sequence of the red swamp crayfish. A total of 4897 SSR loci were identified, with the most abundant type being the di-nucleotide repeat motifs (75.2%), followed by tri- (20.4%), tetra- (3.8%), penta- (0.5%), and hexanucleotide (0.2%) repeats. In total, 1546 SSR markers were validated to be amplified, and 721 of these were identified as polymorphic SSR markers. Fifty polymorphic SSR markers were randomly selected for the identification of the genetic diversity of the 14 red swamp crayfish populations in China. The expected and observed heterozygosity and polymorphism information content were 0.39, 0.30, and 0.29, respectively, on average. The results indicated a medium genetic diversity among the 14 investigated populations. These probably cluster into three genetic populations. The current study provides abundant genetic markers and information on the 14 populations, which can be helpful for genetic diversity estimation and molecular breeding of the red swamp crayfish.


2014 ◽  
Vol 167 ◽  
pp. 5-16 ◽  
Author(s):  
Yue Song ◽  
Lian Fan ◽  
Hui Chen ◽  
Mingyue Zhang ◽  
Qianqian Ma ◽  
...  

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