scholarly journals The Genetic Structure of WildOrobanche cumanaWallr. (Orobanchaceae) Populations in Eastern Bulgaria Reflects Introgressions from Weedy Populations

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Rocío Pineda-Martos ◽  
Antonio J. Pujadas-Salvà ◽  
José M. Fernández-Martínez ◽  
Kiril Stoyanov ◽  
Leonardo Velasco ◽  
...  

Orobanche cumanais a holoparasitic plant naturally distributed from central Asia to south-eastern Europe, where it parasitizes wild Asteraceae species. It is also an important parasitic weed of sunflower crops. The objective of this research was to investigate genetic diversity, population structure, and virulence on sunflower ofO. cumanapopulations parasitizing wild plants in eastern Bulgaria. Fresh tissue of eightO. cumanapopulations and mature seeds of four of them were collectedin situon wild hosts. Genetic diversity and population structure were studied with SSR markers and compared to weedy populations. Two main gene pools were identified in Bulgarian populations, with most of the populations having intermediate characteristics. Cross-inoculation experiments revealed thatO. cumanapopulations collected on wild species possessed similar ability to parasitize sunflower to those collected on sunflower. The results were explained on the basis of an effective genetic exchange between populations parasitizing sunflower crops and those parasitizing wild species. The occurrence of bidirectional gene flow may have an impact on wild populations, as new physiological races continuously emerge in weedy populations. Also, genetic variability of wild populations may favour the ability of weedy populations to overcome sunflower resistance mechanisms.

2011 ◽  
Vol 9 (01) ◽  
pp. 86-96 ◽  
Author(s):  
Lucy M. Díaz ◽  
Héctor F. Buendía ◽  
Myriam C. Duque ◽  
Matthew W. Blair

Colombia, situated at the northern end of the Andes mountains of South America and in proximity to Central America, is an important centre of diversity for common bean (Phaseolus vulgarisL.) that has a mix of cultivated germplasm from both major gene pools (Andean and Mesoamerican) for the species. Microsatellites are a useful marker system for analyzing genetic diversity of this crop and can be analyzed with manual (silver-stain) or automated (ABI) detection systems and using unlabelled or fluorescently labelled markers, respectively. The objectives of this research were to evaluate the genetic diversity of 92 Colombian landraces and gene pool controls with 36 fluorescent and 30 non-fluorescent microsatellite markers and to determine the extent of introgression between the Andean and Mesoamerican gene pools for this germplasm. A comparison of fluorescentversusnon-fluorescent marker systems was performed with 14 loci, which were evaluated with both methods; the fluorescent markers were found to be more precise than the non-fluorescent markers in determining population structure. A combined analysis of 52 microsatellites using the 36 fluorescent markers and 16 non-overlapping, silver-stained markers produced an accurate population structure for the Andean gene pool that separated race Nueva Granada and race Peru genotypes and clearly identified introgression between these races and the gene pools. The results of this research are important for the application of microsatellite markers to diversity analysis in common bean and for the conservation of landraces in Colombia and neighbouring countries of Latin America, where similar germplasm exists and where gene pool or race mixtures also occur.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243238
Author(s):  
Wilson Nkhata ◽  
Hussein Shimelis ◽  
Rob Melis ◽  
Rowland Chirwa ◽  
Tenyson Mzengeza ◽  
...  

Knowledge of genetic diversity in plant germplasm and the relationship between genetic factors and phenotypic expression is vital for crop improvement. This study's objectives were to understand the extent of genetic diversity and population structure in 60 common bean genotypes from East and Southern Africa. The common bean genotypes exhibited significant (p<0.05) levels of variability for traits such as days to flowering (DTF), days to maturity (DTM), number of pods per plant (NPP), number of seeds per pod (NSP), and grain yield per hectare in kilograms (GYD). About 47.82 per cent of the variation among the genotypes was explained by seven principal components (PC) associated with the following agronomic traits: NPP, NFF (nodes to first flower), DTF, GH (growth habit) and GYD. The SNP markers revealed mean gene diversity and polymorphic information content values of 0.38 and 0.25, respectively, which suggested the presence of considerable genetic variation among the assessed genotypes. Analysis of molecular variance showed that 51% of the genetic variation were between the gene pools, while 49% of the variation were within the gene pools. The genotypes were delineated into two distinct groups through the population structure, cluster and phylogenetic analyses. Genetically divergent genotypes such as DRK57, MW3915, NUA59, and VTTT924/4-4 with high yield and agronomic potential were identified, which may be useful for common bean improvement.


2017 ◽  
Vol 47 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Maddalena Carabeo ◽  
Marco Cosimo Simeone ◽  
Marcello Cherubini ◽  
Chiara Mattia ◽  
Francesca Chiocchini ◽  
...  

Studying the genetic diversity and structure of the current forest populations is essential for evaluating the ability to survive future biotic and abiotic changes and planning conservation strategies. Quercus trojana Webb is an eastern Mediterranean tree species with a fragmented distribution range, and its westernmost outposts are located in southern Italy. The demand for timber and cropland over the centuries has severely reduced its occurrence in this part of the range. We assessed the genetic diversity and structure of the extant Italian populations of Q. trojana and derived conservation guidelines. A total of 322 samples were genotyped with six polymorphic nuclear microsatellite markers. A high genetic diversity in all populations, two main gene pools, and a highly divergent single population were observed. Based on the allelic richness and heterozygosity estimation, we identified populations that can be considered as valuable source material for conservation programs and those requiring adequate measures to reestablish gene flow and reduce fragmentation. Finally, a comparison with a set of eastern Mediterranean samples indicated a relationship between the Italian and the Greek gene pools. The need to protect these marginal, disjunct populations was further reinforced.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244666
Author(s):  
Daniel von Maydell ◽  
Heike Lehnert ◽  
Thomas Berner ◽  
Evelyn Klocke ◽  
Wolfram Junghanns ◽  
...  

Caraway (Carum carvi) is a widespread and frequently used spice and medicinal plant with a long history of cultivation. However, due to ongoing climatic changes, the cultivation is becoming increasingly risky. To secure caraway cultivation in future, timely breeding efforts to develop adapted material are necessary. Analysis of genetic diversity can accompany this process, for instance, by revealing untapped gene pools. Here, we analyzed 137 accessions using genotyping by sequencing (GBS). Hence, we can report a broad overview of population structure and genetic diversity of caraway. Population structure was determined using a principal coordinate analysis, a Bayesian clustering analysis, phylogenetic trees and a neighbor network based on 13,155 SNPs. Genotypic data indicate a clear separation of accessions into two subpopulations, which correlates with the flowering type (annual vs. biennial). Four winter-annual accessions were closer related to biennial accessions. In an analysis of molecular variance, genetic variation between the two subpopulations was 7.84%. In addition, we estimated the genome size for 35 accessions by flow cytometry. An average genome size of 4.282 pg/2C (± 0.0096 S.E.) was estimated. Therefore, we suggest a significantly smaller genome size than stated in literature.


2021 ◽  
Author(s):  
Samuel Vanden Abeele ◽  
Steven B. Janssens ◽  
Justin Asimonyio Anio ◽  
Yves Bawin ◽  
Jonas Depecker ◽  
...  

Premise: Many cultivated coffee varieties descend from Coffea canephora, commonly known as Robusta coffee. The Congo Basin has a century long history of Robusta coffee cultivation and breeding, and is hypothesized to be the region of origin of many of the cultivated Robusta varieties. Since little is known about the genetic composition of C. canephora in this region, we assessed the genetic diversity of wild and cultivated C. canephora shrubs in the Democratic Republic of the Congo. Methods: Using 18 microsatellite markers, we studied the genetic composition of wild and backyard-grown C. canephora shrubs in the Tshopo and Ituri provinces, and from the INERA Yangambi Coffee Collection. We assessed genetic clustering patterns, genetic diversity, and genetic differentiation between populations. Key results: Genetic differentiation was relatively strong between wild and cultivated C. canephora shrubs, and both gene pools harbored multiple unique alleles. Strong genetic differentiation was also observed between wild populations. The level of genetic diversity in wild populations was similar to that of the INERA Yangambi Coffee Collection, but local wild genotypes were mostly missing from that collection. Shrubs grown in the backyards were genetically similar to the breeding material from INERA Yangambi. Conclusions: Most C. canephora that is grown in local backyards originated from INERA breeding programs, while a few shrubs were obtained directly from surrounding forests. The INERA Yangambi Coffee Collection could benefit from an enrichment with local wild genotypes, to increase the genetic resources available for breeding purposes, as well as to support ex situ conservation.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11702
Author(s):  
Shikai Guan ◽  
Qian Song ◽  
Jinye Zhou ◽  
Haixia Yan ◽  
Yuxiang Li ◽  
...  

Background The wishbone flower or Torenia fournieri Lind., an annual from tropical Indochina and southern China, is a popular ornamental plant, and many interspecific (T. fournieri × T. concolor) hybrid lines have been bred for the international market. The cultivated lines show a pattern of genetic similarity that correlates with floral color which informs on future breeding strategies. This study aimed to perform genetic analysis and population structure of cultivated hybrid lines comparing with closely related T. concolor wild populations. Methods We applied the retrotransposon based iPBS marker system for genotyping of a total of 136 accessions from 17 lines/populations of Torenia. These included 15 cultivated lines of three series: Duchess (A, B, C); Kauai (D, E, F, G, H, I, J); Little Kiss (K, L, M, N, P) and two wild T. concolor populations (Q and R). PCR products from each individual were applied to estimate the genetic diversity and differentiation between lines/populations. Results Genotyping results showed a pattern of genetic variation differentiating the 17 lines/populations characterized by their specific floral colors. The final PCoA analysis, phylogenetic tree construction, and Bayesian population structural bar plot all showed a clear subdivision of lines/populations analysed. The 15 cultivated hybrid lines and the wild population Q that collected from a small area showed the lowest genetic variability while the other wild population R which sampled from a larger area had the highest genetic variability. Discussion The extremely low genetic variability of 15 cultivated lines indicated that individual line has similar reduction in diversity/heterozygosity from a bottleneck event, and each retained a similar (but different from each other) content of the wild genetic diversity. The genetic variance for the two wild T. concolor populations could be due to our varied sampling methods. The two wild populations (Q, R) and the cultivated hybrid lines (I, K, M, N, P) are genetically more closely related, but strong positive correlations presented in cultivated lines A, C, E, M, and N. These results could be used to guide future Torenia breeding. Conclusions The genetic variation and population structure found in our study showed that cultivated hybrid lines had similar reduction in diversity/heterozygosity from a bottleneck event and each line retained a similar (but different from each other) content of the wild genetic diversity, especially when strong phenotypic selection of floral color overlaps. Generally, environmental factors could induce transposon activation and generate genetic variability which enabled the acceleration of the evolutionary process of wild Torenia species. Our study revealed that wild Torenia populations sampled from broad geographic region represent stronger species strength with outstanding genetic diversity, but selective breeding targeting a specific floral color decreased such genetic variability.


Genes ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 518 ◽  
Author(s):  
Ana Campa ◽  
Ester Murube ◽  
Juan José Ferreira

A common bean (Phaseolus vulgaris) diversity panel of 308 lines was established from local Spanish germplasm, as well as old and elite cultivars mainly used for snap consumption. Most of the landraces included derived from the Spanish common bean core collection, so this panel can be considered to be representative of the Spanish diversity for this species. The panel was characterized by 3099 single-nucleotide polymorphism markers obtained through genotyping-by-sequencing, which revealed a wide genetic diversity and a low level of redundant material within the panel. Structure, cluster, and principal component analyses revealed the presence of two main subpopulations corresponding to the two main gene pools identified in common bean, the Andean and Mesoamerican pools, although most lines (70%) were associated with the Andean gene pool. Lines showing recombination between the two gene pools were also observed, most of them showing useful for snap bean consumption, which suggests that both gene pools were probably used in the breeding of snap bean cultivars. The usefulness of this panel for genome-wide association studies was tested by conducting association mapping for determinacy. Significant marker–trait associations were found on chromosome Pv01, involving the gene Phvul.001G189200, which was identified as a candidate gene for determinacy in the common bean.


2019 ◽  
Vol 305 (10) ◽  
pp. 913-924 ◽  
Author(s):  
Juelina O. dos Santos ◽  
Simon J. Mayo ◽  
Cleiton B. Bittencourt ◽  
Ivanilza M. de Andrade

Abstract The cashew, Anacardium occidentale, is a globally important tropical fruit tree, but little is known about its natural infraspecific systematics. Wild Brazilian populations occur in the cerrado biome and coastal restinga vegetation. We investigated whether wild coastal and domesticated populations could be distinguished genetically using inter-simple repeat molecular markers (ISSRs). In total, 94 polymorphic loci from five primers were used to characterise genetic diversity, structure and differentiation in four wild restinga populations and four domesticated ones from eight localities in Piauí state (30 individuals per population). Genetic diversity was greater overall in wild (%P: 57.2%, I: 0.24, He : 0.15) than domesticated populations (%P: 49.5%, I: 0.19, He : 0.12). Significant structure was observed among the eight populations (between-population variance 22%, ΦPT = 0.217, P ≥ 0.001), but only weak distinctions between wild and domesticated groups. Cluster and principal coordinate analyses showed marked genetic disparity in populations. No correlation of genetic and geographical inter-population distance was found (Mantel test, r = 0.02032, P = 0.4436). Bayesian analysis found an eight-group optimal model (ΔK = 50.2, K = 8), which mostly corresponded to sampled populations. Wild populations show strong genetic heterogeneity within a small geographical area despite probable gene flow between them. Within-population genetic diversity of wild plants varied considerably and was lower where extractive activities by local people are most intense (Labino population). The study underlines the importance of wild populations as in situ genetic reserves and the urgent need for further studies to support their conservation.


2016 ◽  
Vol 94 (4) ◽  
pp. 712
Author(s):  
Pedro Jesús Ruiz-Gil ◽  
Gabriel Chepe-Cruz ◽  
Rubén Humberto Andueza-Noh ◽  
Matilde Margarita Ortiz-García ◽  
Jaime Martínez-Castillo

<p><strong>Background</strong><em>. </em>Understanding the genetic structure of wild relatives of domesticated species is crucial for its conservation and to elucidate the sites of crop domestication. Lima bean is one of the five domesticated <em>Phaseolus</em> species and Mexico is one of its centers of domestication. Recent studies showed the existence of two wild gene pools (MI and MII) of this species in Mexico and suggested that their genetic divergence occurred in southeast Mexico.</p><p><strong>Question</strong><em>. </em>Did MI and MII groups diverged around the Isthmus of Tehuantepec, Mexico?</p><p><strong>Studied species</strong><em>. </em>Lima bean: Neotropical plant species, herbaceous, with an annual/short life cycle and with autogamous tendency.</p><p><strong>Study site and years of study</strong><em>. </em>Seven wild populations were collected in 2012 in the State of Chiapas, México, area underrepresented in previous studies.</p><p><strong>Methods</strong><em>. </em>Genetic diversity and grouping patterns of collected populations and their relationship to MI and MII groups were analyzed at eight microsatellite loci.</p><p><strong>Results</strong>. High genetic structure (<em>F</em><sub>ST</sub>: 0.42 to 0.96) and a high level of genetic diversity (<em>H</em><sub>E </sub>= 0.48) were found. The analyses, and presence of admixed populations in MI and MII, suggested that the genetic divergence of these groups is an ongoing process centered around the Isthmus of Tehuantepec.</p><p><strong>Conclusions</strong><em>. </em>Our results support the hypothesis that MI and MII groups diverged around the Isthmus of Tehuantepec; however, sampling should be increased both at population and genomic levels, to determine the precise organization of the genetic diversity of wild <em>P. lunatus</em> from Mexico.</p>


2020 ◽  
Vol 7 (1) ◽  
pp. 3-13
Author(s):  
V. Iovenko ◽  
Yu. Vdovychenko ◽  
N. Pysarenko ◽  
K. Skrepets ◽  
I. Hladii

Aim. To determine the level of polymorphism of some genes, pertaining to the quantitative traits of sheep and to study the genetic diversity and population structure of breeds of Askanian sheep and one of its hybrids. Methods. Molecular–genetic, population–statistical, biometric methods. Results. The genetic structure of populations of the Askanian Fine-Fleeced (AFF, n = 33), Askanian Meat-and-Wool (AMW, n = 22) and Askanian Karakul (AK, n = 46) breeds and a hybrid of Askanian Fine-Fleeced × Texel (AFFT, n = 40) has been studied for the fi rst time in terms of the polymorphisms of the following qualitative trait genes (loci) : meat productivity genes: ovine growth hormone (GH), calpastatin (CAST) and myostatin (MSTN); prolifi cacy genes: Booroola (fecundity gene FecB) and bone morphogenetic protein (BMP15). The sheep in all studied breeds and the hybrid mentioned above are characterized by the polymorphism of two loci, GH and CAST. The other three loci studied did not show polymorphism for the markers studied. GH is present as two genotypes (A/A, A/B), and CAST as three genotypes (A/A, A/B, B/B). The remaining genes were found to be in the monomorphic state. The frequencies of certain genotypes and alleles change in the direction from fi ne–fl eeced to meat animals. For instance, the concentration of heterozygous growth hormone (GH) genotype A/B increases from 0.0 % (AFFB) to 38.2 % (AMWB), and the concentration of allele A – from 0.083 to 0.191. The live bodyweight of fi ne–fl eeced lambs with GH genotype A/B at birth equaled 4.5 kg, and those with homozygous genotype A/A – 4.9 kg (P < 0.001). Therefore, homozygous genotype А/А determined the increased level of meat productivity of sheep. A similar dependence was established at birth for the Askanian Karakul breed. Conclusions. The specifi city of genetic structure of Askanian breeds and hybrid is polymorphism of the GH and CAST and absence of polymorphism of BMP15 and FecB genes, determining the prolifi cacy (reproduction) trait. According to the distribution of polymorphic loci variants, the gene pools of Askanian Meat-and-Wool breed and the local Askanian-Texel hybrid are closely related and therefore explains the same direction of their productivity. At the same time, all populations are in a state of genetic equilibrium according to Hardy-Weinberg, which indicates a high level of their consolidation. Sheep which have the A/A homozygote of the gene growth hormone are characterized by an increased level of the body weight development.


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