scholarly journals Population Structure, Genetic Diversity, and Gene Introgression of Two Closely Related Walnuts (Juglans regia and J. sigillata) in Southwestern China Revealed by EST-SSR Markers

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 646 ◽  
Author(s):  
Xiao-Ying Yuan ◽  
Yi-Wei Sun ◽  
Xu-Rong Bai ◽  
Meng Dang ◽  
Xiao-Jia Feng ◽  
...  

The common walnut (Juglans regia L.) and iron walnut (J. sigillata Dode) are well-known economically important species cultivated for their edible nuts, high-quality wood, and medicinal properties and display a sympatric distribution in southwestern China. However, detailed research on the genetic diversity and introgression of these two closely related walnut species, especially in southwestern China, are lacking. In this study, we analyzed a total of 506 individuals from 28 populations of J. regia and J. sigillata using 25 EST-SSR markers to determine if their gene introgression was related to sympatric distribution. In addition, we compared the genetic diversity estimates between them. Our results indicated that all J. regia populations possess slightly higher genetic diversity than J. sigillata populations. The Geostatistical IDW technique (HO, PPL, NA and PrA) revealed that northern Yunnan and Guizhou provinces had high genetic diversity for J. regia while the northwestern Yunnan province had high genetic diversity for J. sigillata. AMOVA analysis revealed that significant genetic variation was mainly distributed within population as 73% in J. regia and 76% in J. sigillata. The genetic differentiation (FST) was 0.307 between the two walnut species (p < 0.0001), which was higher than FST values within populations (J. regia FST = 0.265 and J. sigillata FST = 0.236). However, the STRUCTURE analysis of the J. regia and J. sigillata populations revealed two genetic clusters in which gene introgression exists, therefore, the boundary of separation between these two walnut species is not clear. Moreover, these results were validated by NJ and UPGMA analysis with additional conformation from the PCoA. Based on the SSR data, our results indicate that J. sigillata is an ecotype of J. regia. Taken together, these results reveal novel information on population genetics and provide specific geographical regions containing high genetic diversity of the Juglans species sampled, which will assist in future conservation management.

2019 ◽  
Vol 15 (2) ◽  
pp. 65 ◽  
Author(s):  
Wartono Wartono ◽  
Suryo Wiyono ◽  
Muhamad Syukur ◽  
Giyanto Giyanto ◽  
Kristianto Nugroho ◽  
...  

<p>Chili (Capsicum annuum L.) is an important horticultural crop which possesses high genetic diversity. Their genetic diversity needs to be assessed through molecular marker-based analysis to facilitate chili breeding scheme. The objective of the study was to analyze the genetic diversity of 41 chili genotypes using Simple Sequence Repeat (SSR) markers. Eleven SSR markers were used to amplify all genotypes through PCR technique, visualized on Polyacrylamide Gel Electrophoresis (PAGE). The data were analyzed using NTSYSpc version 2.1 and PowerMarker version 3.25 softwares. Results showed that the average of<br />SSR alleles was 7.9 with a range of 4-11 alleles per marker. All SSR markers showed PIC value &gt;0.5, indicating their suitable use for chili genetic studies. Cluster analysis of 41 genotypes generated three main groups according to coefficient similarity of 77.4%. The genetic clusters appeared as reflection of the genetic background of each genotype. In addition, the SSR markers used can identify potential parent as indicated by the genetic distance between genotypes. The highest genetic diversity (0.698) was demonstrated by combinations of Yuni × Ayesha, Yuni × Ayesha 2, and Yuni × Namira. The estimated genetic diversity produced by SSR markers in this study should be useful as guidance for chili breeders to select suitable parents for new cultivar development for high productivity and resistance to diseases.</p>


PLoS ONE ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. e0176197 ◽  
Author(s):  
Lucie Meyer ◽  
Romain Causse ◽  
Fanny Pernin ◽  
Romain Scalone ◽  
Géraldine Bailly ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8038
Author(s):  
Yanli Xiong ◽  
Wenhui Liu ◽  
Yi Xiong ◽  
Qingqing Yu ◽  
Xiao Ma ◽  
...  

Hosting unique and important plant germplasms, the Qinghai-Tibet Plateau (QTP), as the third pole of the world, and Xinjiang, located in the centre of the Eurasian continent, are major distribution areas of perennial Triticeae grasses, especially the widespread Elymus species. Elymus excelsus Turcz. ex Griseb, a perennial forage grass with strong tolerance to environmental stresses, such as drought, cold and soil impoverishment, can be appropriately used for grassland establishment due to its high seed production. To provide basic information for collection, breeding strategies and utilization of E. excelsus germplasm, microsatellite markers (SSR) were employed in the present study to determine the genetic variation and population structure of 25 wild accessions of E. excelsus from Xinjiang (XJC) and the QTP, including Sichuan (SCC) and Gansu (GSC) of western China. Based on the 159 polymorphic bands amplified by 35 primer pairs developed from three related species, the average values of the polymorphic information content (PIC), marker index (MI), resolving power (Rp), Nei’s genetic diversity (H) and Shannon’s diversity index (I) of each pair of primers were 0.289, 1.348, 1.897, 0.301 and 0.459, respectively, validating that these SSR markers can also be used for the evaluation of genetic diversity of E. excelsus germplasms, and demonstrating the superior versatility of EST-SSR vs. G-SSR. We found a relatively moderate differentiation (Fst = 0.151) among the XJC, SCC and GSC geo-groups, and it is worth noting that, the intra-group genetic diversity of the SCC group (He = 0.197) was greater than that of the GSC (He = 0.176) and XJC (He = 0.148) groups. Both the Unweighted Pair Group Method with Arithmetic (UPGMA) clustering and principal coordinates analysis (PCoA) divided the 25 accessions into three groups, whereas the Bayesian STRUCTURE analysis suggested that E. excelsus accessions fell into four main clusters. Besides, this study suggested that geographical distance and environmental variables (annual mean precipitation and average precipitation in growing seasons), especially for QTP accessions, should be combined to explain the population genetic differentiation among the divergent geographical regions. These data provided comprehensive information about these valuable E. excelsus germplasm resources for the protection and collection of germplasms and for breeding strategies in areas of Xinjiang and QTP in western China.


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.


2020 ◽  
Author(s):  
Yibing Zeng ◽  
Tao Xiong ◽  
Bei Liu ◽  
Elma Carstens ◽  
Xiangling Chen ◽  
...  

Phyllosticta citriasiana is the causal agent of citrus tan spot, an important pomelo disease in Asia. At present, there is little or no information on the epidemiology or population structure of P. citriasiana. Using simple sequence repeat (SSR) markers, 94 isolates obtained from three pomelo production regions in southern/southeastern China were analyzed. The analyses showed high genetic diversity in each of the three geographic populations. A STRUCTURE analysis revealed two genetic clusters among the 94 isolates, one geographic population was dominated by genotypes in one cluster while the other two geographic populations were dominated by genotypes of the second cluster. P. citriasiana has a heterothallic mating system with two idiomorphs, MAT1-1 and MAT1-2. Analyses using mating type-specific primers revealed that both mating types were present in all three geographic populations, and in all three populations the mating type ratios were in equilibrium. Although the sexual stage of the fungus has not been discovered yet, analyses of allelic associations indicated evidence for sexual and asexual reproduction within and among populations. Despite the observed genetic differentiation among the three geographic populations, evidence for long-distance gene flow was found.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yuejin Zhang ◽  
Yuanyuan Chen ◽  
Ruihong Wang ◽  
Ailin Zeng ◽  
Michael K. Deyholos ◽  
...  

A large scale of EST sequences of Polyporales was screened in this investigation in order to identify EST-SSR markers for various applications. The distribution of EST sequences and SSRs in five families of Polyporales was analyzed, respectively. Mononucleotide was the most abundant type, followed by trinucleotide. Among five families, Ganodermataceae occupied the most SSR markers, followed by Coriolaceae. Functional prediction of SSR marker-containing EST sequences inGanoderma lucidumobtained three main groups, namely, cellular component, biological process, and molecular function. Thirty EST-SSR primers were designed to evaluate the genetic diversity of 13 naturalPolyporus umbellatusaccessions. Twenty one EST-SSRs were polymorphic with average PIC value of 0.33 and transferability rate of 71%. These 13P.umbellatusaccessions showed relatively high genetic diversity. The expected heterozygosity, Nei’s gene diversity, and Shannon information index were 0.41, 0.39, and 0.57, respectively. Both UPGMA dendrogram and principal coordinate analysis (PCA) showed the same cluster result that divided the 13 accessions into three or four groups.


2006 ◽  
Vol 4 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Elena K. Khlestkina ◽  
Rajeev K. Varshney ◽  
Marion S. Röder ◽  
Andreas Graner ◽  
Andreas Börner

Molecular investigations of qualitative and quantitative changes in the genetic diversity of cultivated crops are useful for plant breeding and the management of crop genetic resources. A genotyping study, based on 28 genomic (g-SSR) and 13 expressed sequence tag-derived (e-SSR) microsatellite markers uniformly distributed across the barley genome, was conducted on samples of cultivated barley (Hordeum vulgare L.) collected at intervals of 40–50 years in three comparable geographical regions in Austria, Albania and India. The analysis indicated an absence of any significant differences either in the total number of alleles per locus or in g-SSR and e-SSR polymorphic information content (PIC) values from the Indian and Austrian materials. However, a slight reduction in genetic diversity was noted among the materials collected in Albania. The trend in numbers of collection mission-specific SSR alleles suggests significant allele flow over the time interval sampled. The g-SSRs yielded a higher mean number of alleles per locus and a superior PIC than the e-SSR markers. We conclude that a qualitative, rather than a quantitative shift in diversity has taken place over time, and that g-SSR markers detect more diversity than do e-SSR markers.


Author(s):  
Ahmed Medhat Mohamed Al-Naggar ◽  
Mohamed Abd El-Maboud Abd El-Shafi ◽  
Mohamed Helmy El-Shal ◽  
Ali Hassan Anany

To increase the genetic progress in wheat (Triticum aestivum L.) yield, breeders search for germplasm of high genetic diversity, one of them is the landraces. The present study aimed at evaluating genetic diversity of 20 Egyptian wheat landraces and two cultivars using microsatellite markers (SSRs). Ten SSR markers amplified a total of 27 alleles in the set of 22 wheat accessions, of which 23 alleles (85.2%) were polymorphic. The majority of the markers showed high polymorphism information content (PIC) values (0.67-0.94), indicating the diverse nature of the wheat accessions and/or highly informative SSR markers used in this study. The genotyping data of the SSR markers were used to assess genetic variation in the wheat accessions by dendrogram. The highest genetic distance was found between G21 (Sakha 64; an Egyptian cultivar) and the landrace accession No. 9120 (G11). These two genotypes could be used as parents in a hybridization program followed by selection in the segregating generations, to identify some transgressive segregates of higher grain yield than both parents. The clustering assigned the wheat genotypes into four groups based on SSR markers. The results showed that the studied SSR markers, provided sufficient polymorphism and reproducible fingerprinting profiles for evaluating genetic diversity of wheat landraces. The analyzed wheat landraces showed a good level of genetic diversity at the molecular level. Molecular variation evaluated in this study of wheat landraces can be useful in traditional and molecular breeding programs.


2021 ◽  
Author(s):  
Tanzeem Fatima ◽  
Ashutosh Srivastava ◽  
Vageeshbabu S Hanur ◽  
M. Srinivasa Rao

Sandalwood (Santalum album L.) is highly valued aromatic tropical tree. It is known for its high quality heartwood and oil. In this study 39 genic and genomic SSR markers were used to analyze the genetic diversity and population structure of 177 S. album accessions from 14 populations of three states in India. High genetic diversity was observed in terms of number of alleles 127 expected heterozygosity (He) ranged from 0.63-0.87 and the average PIC was 0.85. The selected population had relatively high genetic diversity with Shannons information index (I) >1.0. 0.02 mean coefficient of genetic differentiation (FST) and 10.55 gene flow were observed. AMOVA revealed that 92% of the variation observed within individuals. Based on cluster and Structure result individuals were not clustered as per their geographical origin. Furthermore the clusters were clearly distinguished by principal component analysis analysis and the result revealed that PC1 reflected the moderate contribution in genetic variation (6%) followed by PC2 (5.5%). From this study, high genetic diversity and genetic differentiation was found in S. album populations. The genetic diversity information of S. album populations can be used for selection of superior genotypes and germplasm conservation to promote the tree improvement of S. album populations.


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