scholarly journals Genetic diversity and population structure of Robinia pseudoacacia from six improved variety bases in China as revealed by simple sequence repeat markers

Author(s):  
Qi Guo ◽  
Sen Cao ◽  
Li Dong ◽  
Xiuyu Li ◽  
Jiangtao Zhang ◽  
...  

AbstractRobinia pseudoacacia is an important afforestation tree introduced to China in 1878. In the present study, we examined the genetic diversity among 687 strains representing four improved varieties and two secondary provenances, comprising 641 clones and 46 seedlings. Ninety-one simple sequence repeats (SSRs) were selected through segregation analysis and polymorphism characterization, and all sampled individuals were genotyped using well-characterized SSR markers. After excluding loci with non-neutral equilibrium, missing locus data and null alleles, we used 36 primer pairs to assess the genetic diversity of these germplasm resources, revealing vast genetic differentiation among the samples, with an average of 8.352 alleles per locus and a mean Shannon′s index of 1.302. At the population level, the partitioning of variability was assessed using analysis of molecular variance, which revealed 93% and 7% variation within and among collection sites, respectively. Four clusters were detected using structure analysis, indicating a degree of genetic differentiation among the six populations. Insights into the genetic diversity and structure of R. pseudoacacia provide a theoretical basis for the conservation, breeding and sustainable development in China.

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12325
Author(s):  
Lu Gong ◽  
Danchun Zhang ◽  
Xiaoxia Ding ◽  
Juan Huang ◽  
Wan Guan ◽  
...  

Background Amomum villosum Lour. is the plant that produces the famous traditional Chinese medicine Amomi Fructus. Frequent habitat destruction seriously threatens A. villosum germplasm resources. Genetic diversity is very important to the optimization of germplasm resources and population protection, but the range of inherited traits within A. villosum is unclear. In this study, we analyzed the genetic diversity and genetic structures of A. villosum populations in Guangdong and constructed a local reference DNA barcode library as a resource for conservation efforts. Methods DNA barcoding and Inter-Simple Sequence Repeat (ISSR) markers were used to investigate the population genetics of A. villosum. Five universal DNA barcodes were amplified and used in the construction of a DNA barcode reference library. Parameters including percentage of polymorphic sites (PPB), number of alleles (Na), effective number of alleles (Ne), Nei’s gene diversity index (H), and Shannon’s polymorphism information index (I) were calculated for the assessment of genetic diversity. Genetic structure was revealed by measuring Nei’s gene differentiation coefficient (Gst), total population genetic diversity (Ht), intra-group genetic diversity (Hs), and gene flow (Nm). Analysis of molecular variance (AMOVA), Mantel tests, unweighted pair-group method with arithmetic mean (UPGMA) dendrogram, and principal co-ordinates (PCoA) analysis were used to elucidate the genetic differentiation and relationship among populations. Results A total of 531 sequences were obtained from the five DNA barcodes with no variable sites from any of the barcode sequences. A total of 66 ISSR bands were generated from A. villosum populations using the selected six ISSR primers; 56 bands, 84.85% for all the seven A. villosum populations were polymorphic. The A. villosum populations showed high genetic diversity (H = 0.3281, I = 0.4895), whereas the gene flow was weak (Nm = 0.6143). Gst (0.4487) and AMOVA analysis indicated that there is obvious genetic differentiation amongA. villosum populations and more genetic variations existed within each population. The genetic relationship of each population was relatively close as the genetic distances were between 0.0844 and 0.3347.


BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances (Missouri, Iowa, Washington, Louisiana, and Tennessee (USA), and Quebec in Canada) of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) per locus ranged from 0.070 to 0.905, and the average polymorphic information content (PIC) was 0.535. The provenance ‘Was’ had a relatively low genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon’s information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931, respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, individuals distributed in the Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a small gene flow and high degree of genetic differentiation compared with the other provenances, and was classified into one group. There was a significant relationship between genetic distance and geographical distance. Conclusions P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals. Individuals reflecting population genetic information can be selected to build a core germplasm bank. Meanwhile, the results could provide theoretical support for the scientific management and efficient utilization of P. deltoides genetic resources, and promote the development of molecular marker-assisted breeding of poplar.


2017 ◽  
Vol 16 (3) ◽  
pp. 284-287
Author(s):  
Bruno C. Rossini ◽  
Mariá B. Kampa ◽  
Celso L. Marino ◽  
Fernanda Bortolanza Pereira ◽  
Fábio M. Alves ◽  
...  

AbstractIn this study, we isolate and analyse a new set of microsatellite loci for Cattleya walkeriana. Twenty-two primer pairs were screened for C. walkeriana (n = 32) and assessed for their transferability to Cattleya loddigesii (n = 12) and Cattleya nobilior (n = 06). All loci amplified for C. walkeriana; however, for C. loddigesii and C. nobilior, four and five primers, respectively, did not present amplification. The polymorphic loci presented between 2 and 13 alleles per locus for both C. walkeriana and C. loddigesii, with respective averages of 5.1 and 4.2. For C. nobilior, we found between two and five alleles per locus, with an average of 2.6. For C. walkeriana, observed heterozygosity varied from 0.100 to 0.966, whereas expected heterozygosity ranged from 0.097 to 0.900. The observed and expected heterozygosity for C. loddigesii and C. nobilior were also estimated. We found no significant linkage disequilibrium between any pair of loci, and evidence of null alleles at four loci (Cw16, Cw24, Cw30 and Cw31) for C. walkeriana. The combined power to exclude the first parent and combined non-exclusion probability of identity were 0.999 and 2.3 × 10−20, respectively. These new loci can be used in studies of germplasm resources, and assessments of genotypic and genetic diversity and population structure, thus improving the accuracy of such analyses and their applicability in the conservation and protection of these endangered species.


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.


2011 ◽  
Vol 149 (5) ◽  
pp. 617-624 ◽  
Author(s):  
P. SOENGAS ◽  
M. E. CARTEA ◽  
M. FRANCISCO ◽  
M. LEMA ◽  
P. VELASCO

SUMMARYBrassica rapa subsp. rapa L. includes three different crops: turnips (roots), turnip greens (leaves) and turnip tops (inflorescences). A collection of B. rapa subsp. rapa from north-western Spain is currently kept at ‘Misión Biológica de Galicia’ (a research centre of the Consejo Superior de Investigaciones Científicas (CSIC), Spain). This collection has been characterized based on morphological and agronomical traits. A better understanding of the genetic diversity present in the collection is necessary in order to optimize its use and maintenance. The objectives of the present work were to assess the genetic diversity present in the B. rapa subsp. rapa collection, to establish genetic relationships among populations and to study the genetic structure of the collection. Eighty populations were analysed based on 18 simple sequence repeats (SSRs). Populations showed a broad range of genetic diversity, thus offering good potential for further genetic improvement. Most of the variability was found within the population level, probably due to high rates of allogamy, to migration and/or interchange of seed among local growers. Populations showed a low level of differentiation, grouping in just one cluster, and therefore they can be considered as samples of a highly variable metapopulation that can be used for B. rapa breeding programmes.


2019 ◽  
Vol 18 (4) ◽  
pp. 93-109
Author(s):  
Ilaria Marcotuli ◽  
Andrea Mazzeo ◽  
Domenica Nigro ◽  
Stefania Lucia Giove ◽  
Angelica Giancaspro ◽  
...  

Modern technologies and accurate information on genetic diversity and structure are contributing to improve the plant breeding, in particular for all the minor species with a lack of data. Genetic diversity of 139 different Ficus carica L. genotypes collected from Italy and Croatia, and divided into two subgroups: uniferous (only main crop) and biferous (breba and main crop), was investigated using 49 microsatellite markers. A total of 70 alleles were generated, of which 64 (91.4%) showed a polymorphic pattern indicating high level of genetic diversity within the studied collection. The mean heterozygosity over the 64 single locus microsatellites was 0.33 and the expected and observed averaged variance were 16.50 and 184.08, respectively. The 139 fig genotypes formed two clusters in the PCoA analysis, suggesting a division between Italian and Croatian genotypes. Moreover, the fig accessions could be divided into two main clusters based on the STRUCTURE analysis according to the biological type, uniferous or biferous, with partly overlapping varieties. In conclusion, our results demonstrated that molecular markers were able to discriminate among genotypes and useful for the authentication of fig tree varieties (homonymies and synonymies).


2008 ◽  
Vol 88 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Chu-Chuan Fan ◽  
Nicola Pecchioni ◽  
Long-Qing Chen

Calycanthus chinensis Cheng et S.Y. Chang, a tertiary relic species in China, is a shade-loving and deciduous bush withan elegant shape and beautiful flower of high ornamental value. It was widely planted in gardens and miniature scapes in China.The objective of this study was to characterize the genetic variation and structure in the three extant populations of the species, in order to provide useful information for a future conservation strategy. Twenty-two of 120 RAPD primers were selected and a total of 257 stable and clear DNA fragments were scored. Calycanthus chinensis showed a lower level of genetic diversity. At the population level, the percentage of polymorphic loci, Nei's gene diversity and Shannon’s information index were 40.9%, 0.1641 and 0.2386, respectively; while at the species level, the corresponding values were 59.1%, 0.2097 and 0.3123, respectively. The estimates of genetic differentiation based on Shannon’s information index (0.2360), Nei’s gene diversity (0.2175) and AMOVA (24.94%) were very similar, and significantly higher than the average genetic differentiation reported in outcrossed spermatophyte. So it suggested high genetic differentiation emerged among populations of C. chinensis. Genetic relationships among populations were assessed by Nei’s standard genetic distance, which suggested that the Tiantai population was genetically distinct from the other two populations. Moreover, the genetic distance was significantly correlated with geographical distance among populations (r = 0.997, t > t0.05). The gene flow (Nm) was 0.8994, indicating that gene exchange among populations was restricted. A conservation strategy was proposed based on the low gene flow and habitat deterioration, which are contributing to the endangered status of this species. Key words: Genetic diversity, endangered plant, population genetics, RAPD


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1471
Author(s):  
Hamed Yousefzadeh ◽  
Shahla Raeisi ◽  
Omid Esmailzadeh ◽  
Gholamali Jalali ◽  
Malek Nasiri ◽  
...  

Sorbus aucuparia (Rosaceae) is a small tree species widely distributed in Eurasia. The Hyrcanian forest is the southernmost distribution limit of this species. Severe habitat degradation and inadequate human interventions have endangered the long-term survival of this species in this region, and it is necessary to develop and apply appropriate management methods to prevent the loss of its genetic diversity. In this study, we used 10 SSR markers in order to evaluate the genetic diversity of this taxon. Leaf samples were collected from five known populations of S. aucuparia throughout its distribution area in the Hyrcanian forest. Expected heterozygosity ranged from 0.61 (ASH) to 0.73, and according to the M-ratio, all populations showed a significant reduction in effective population size, indicating a genetic bottleneck. Global FST was not statistically significant and attained the same values with and without excluding null alleles (ENA) correction (FST = 0.12). Bayesian analysis performed with STRUCTURE defined two genetic clusters among the five known populations, while the results of discriminant analysis of principal components (DAPC) identified three distinct groups. The average proportion of migrants was 22. In general, the gene flow was asymmetrical, with the biggest differences between immigration and emigration in Barzekoh and Asbehriseh. The Mantel test showed that there was no significant correlation between genetic distance (FST) and geographic distance in S. aucuparia. The best pathway for theoretical gene flow is located across the coast of the Caspian Sea and significant spatial autocorrelation was observed in only one population. In order to reduce the extinction risk of very small and scattered populations of S. aucuparia in the Hyrcanian forest, it is very important to establish and/or enhance the connectivity through habitat restoration or genetic exchange.


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