scholarly journals Reproductive development and genetic structure of the mycoheterotrophic orchid Pogoniopsis schenckii Cogn.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mariana Ferreira Alves ◽  
Fabio Pinheiro ◽  
Carlos Eduardo Pereira Nunes ◽  
Francisco Prosdocimi ◽  
Deise Schroder Sarzi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Breeding System ◽  
Embryo Sac ◽  
Field Tests ◽  
Reproductive Organs ◽  
Reproductive Process ◽  
Low Genetic Diversity ◽  
Genetic Diversity And Structure ◽  
Fungal Hyphae

Abstract Background Pogoniopsis schenckii Cogn. is a mycoheterotrophic orchid that can be used as a model to understand the influence of mycoheterotrophy at different stages of the reproductive cycle. We aimed to verify the presence of endophytic and epiphytic fungi at each stage of the reproductive process and investigated how the breeding system may relate to genetic structure and diversity of populations. In this study we performed anatomical and ultrastructural analyses of the reproductive organs, field tests to confirm the breeding system, and molecular analysis to assess genetic diversity and structure of populations. Results During the development of the pollen grain, embryo sac and embryogenesis, no fungal infestation was observed. The presence of endophytic fungal hyphae was observed just within floral stems and indehiscent fruit. Beyond assuring the presence of fungus that promote seed germination, specific fungi hyphae in the fruit may affect other process, such as fruit ripening. As other mycoheterotrophic orchids, P. schenckii is autogamous, which may explain the low genetic diversity and high genetic structure in populations. Conclusions We discuss an interesting interaction: fungal hyphae in the indehiscent fruit. These fungal hyphae seem to play different roles inside fruit tissues, such as acting in the fruit maturation process and increasing the proximity between fungi and plant seeds even before dispersion occurs. As other mycoheterotrophic orchids, P. schenckii is autogamous, which may explain the low genetic diversity and high genetic structure in populations. Altogether, our findings provide important novel information about the mechanisms shaping ecology and evolution of fragmented populations of mycoheterotrophic plant.

scholarly journals High gene flow maintains wide-range species cohesion in a Neotropical epiphyte (Tillandsia aeranthos, Bromeliaceae)

2020 ◽  
Vol 194 (2) ◽  
pp. 239-252
Author(s):  
Felipe Aoki-Gonçalves ◽  
Marcos Vinicius Dantas De Queiroz ◽  
Thais De Beauclair Guimarães ◽  
Viviana Solís Neffa ◽  
Clarisse Palma-Silva
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Breeding System ◽  
Ecological Data ◽  
Pollination Experiments ◽  
Controlled Pollination ◽  
Wide Range ◽  
Genetic Diversity And Structure ◽  
Assignment Analysis

Abstract Studies of patterns of genetic diversity, genetic structure and ecological data across geographical ranges of species allow us to test hypotheses about the evolutionary responses of organisms to fluctuations in habitat connectivity and availability. Here we present a study aiming to assess genetic diversity, population structure and breeding system across the geographical distribution of a subtropical epiphyte, Tillandsia aeranthos (Bromeliaceae), endemic to the Plata River basin (Pampa biome). Seven nuclear microsatellite markers were genotyped in 203 individuals from 13 localities across Brazil and Argentina and 14 plastid regions were sequenced for a subset of the individuals. Additionally, we performed controlled pollination experiments to discuss correlations between breeding system, genetic diversity and structure in the species. Nuclear diversity levels were high (HE = 0.806, HO = 0.745, allelic richness = 5.860) with no haplotype differentiation detected (c. 9 kpb sequenced). Bayesian assignment analysis, supported by principal coordinate analysis and analysis of molecular variance, show low genetic structure across the studied area (FST = 0.031, P < 0.001). Controlled pollination experiments indicated complete self-incompatibility in all localities analysed. Our results show effective gene flow maintaining low genetic structure between localities for T. aeranthos across an extensive area in the Pampa.

scholarly journals Conservation genetics of the threatened plant species Physaria filiformis (Missouri bladderpod) reveals strong genetic structure and a possible cryptic species

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247586
Author(s):  
Christine E. Edwards ◽  
Brooke C. Tessier ◽  
Joel F. Swift ◽  
Burgund Bassüner ◽  
Alexander G. Linan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Plant Species ◽  
Genetic Drift ◽  
Rare Species ◽  
Ex Situ ◽  
Ouachita Mountains ◽  
Genetic Diversity And Structure ◽  
Genetic Clusters

Understanding genetic diversity and structure in a rare species is critical for prioritizing both in situ and ex situ conservation efforts. One such rare species is Physaria filiformis (Brassicaceae), a threatened, winter annual plant species. The species has a naturally fragmented distribution, occupying three different soil types spread across four disjunct geographical locations in Missouri and Arkansas. The goals of this study were to understand: (1) whether factors associated with fragmentation and small population size (i.e., inbreeding, genetic drift or genetic bottlenecks) have reduced levels of genetic diversity, (2) how genetic variation is structured and which factors have influenced genetic structure, and (3) how much extant genetic variation of P. filiformis is currently publicly protected and the implications for the development of conservation strategies to protect its genetic diversity. Using 16 microsatellite markers, we genotyped individuals from 20 populations of P. filiformis from across its geographical range and one population of Physaria gracilis for comparison and analyzed genetic diversity and structure. Populations of P. filiformis showed comparable levels of genetic diversity to its congener, except a single population in northwest Arkansas showed evidence of a genetic bottleneck and two populations in the Ouachita Mountains of Arkansas showed lower genetic variation, consistent with genetic drift. Populations showed isolation by distance, indicating that migration is geographically limited, and analyses of genetic structure grouped individuals into seven geographically structured genetic clusters, with geographic location/spatial separation showing a strong influence on genetic structure. At least one population is protected for all genetic clusters except one in north-central Arkansas, which should therefore be prioritized for protection. Populations in the Ouachita Mountains were genetically divergent from the rest of P. filiformis; future morphological analyses are needed to identify whether it merits recognition as a new, extremely rare species.

scholarly journals Pronounced genetic structure and low genetic diversity in European red-billed chough (Pyrrhocorax pyrrhocorax) populations

2012 ◽  
Vol 13 (5) ◽  
pp. 1213-1230 ◽  
Author(s):  
Marius A. Wenzel ◽  
Lucy M. I. Webster ◽  
Guillermo Blanco ◽  
Malcolm D. Burgess ◽  
Christian Kerbiriou ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Low Genetic Diversity

scholarly journals Genetic structure and diversity in Sorghum bicolor (L.) Moench landraces from marginal sorghum production lands in Senegal, based on SSR markers

2020 ◽  
Vol 7 (3) ◽  
pp. 134-144
Author(s):  
Amy Bodian ◽  
Bassiaka Ouattara ◽  
Awa Sarr ◽  
Boubacar Gano ◽  
Mbaye-Ndoye Sall ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Production Systems ◽  
Classification Model ◽  
Germplasm Management ◽  
Genetic Diversity And Structure ◽  
Food And Feed ◽  
Sorghum Production ◽  
In Situ Management

Data on sorghum genetic diversity in Senegal are missing despite its importance in the food and feed in the country. In order to contribute to the sustainable in situ management of sorghum germplasm, we investigated its genetic diversity and structure in its marginal production areas. Investigations were focused on Thiès, Diourbel and Kédougou regions where sorghum landraces have been less investigated and genetic information on landraces is unknown. A total of 148 sorghum accessions representative of landraces used in production systems have been sampled and analyzed with 30 microsatellite markers. A total of 138 alleles have been recorded. The number of alleles per locus varied from 3 (7 loci) to 8 (3 loci). The observed heterozygosity varied from 0 to 0.62. The low genetic distance (0.12) was recorded between Thiès and Diourbel populations and the highest distance (0.22) between Thiès and Kédougou populations. Dendrogram obtained according to Neighbour joining classification model allowed the classification of sorghum accessions into three main groups. The Genetic structure is not function to the regions indicating that landraces are not specific to a region. The results are a first step toward the sustainable in situ management of genetic resources. Data on the whole range of existing diversity of sorghum in Senegal is an important key for its germplasm management; so, the genotyping must be extended to accessions from the whole country.

scholarly journals Population genetics of the freshwater fish Prochilodus magdalenae (Characiformes: Prochilodontidae), using species-specific microsatellite loci

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10327
Author(s):  
Ricardo M. Landínez-García ◽  
Juan Carlos Narváez ◽  
Edna J. Márquez
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Freshwater Fish ◽  
Microsatellite Loci ◽  
Natural Populations ◽  
Genetic Stock ◽  
High Genetic Diversity ◽  
Genetic Diversity And Structure ◽  
Genetic Stocks ◽  
Species Specific

Prochilodus magdalenae is a freshwater fish endemic to the Colombian Magdalena-Cauca and Caribbean hydrographic basins. The genetic structure patterns of populations of different members of Prochilodus and the historic restocking of its depleted natural populations suggest that P. magdalenae exhibits genetic stocks that coexist and co-migrate throughout the rivers Magdalena, Cauca, Cesar, Sinú and Atrato. To test this hypothesis and explore the levels of genetic diversity and population demography of 725 samples of P. magdalenae from the studied rivers, we developed a set of 11 species-specific microsatellite loci using next-generation sequencing, bioinformatics, and experimental tests of the levels of diversity of the microsatellite loci. The results evidenced that P. magdalenae exhibits high genetic diversity, significant inbreeding coefficient ranging from 0.162 to 0.202, and signs of erosion of the genetic pool. Additionally, the population genetic structure constitutes a mixture of genetic stocks heterogeneously distributed along the studied rivers, and moreover, a highly divergent genetic stock was detected in Chucurí, Puerto Berrío and Palagua that may result from restocking practices. This study provides molecular tools and a wide framework regarding the genetic diversity and structure of P. magdalenae, which is crucial to complement its baseline information, diagnosis and monitoring of populations, and to support the implementation of adequate regulation, management, and conservation policies.

scholarly journals Genetic structure of Oryza glumaepatula wild rice populations and evidence of introgression from O. sativa in Costa Rica

2015 ◽  
Author(s):  
Eric J Fuchs ◽  
Allan Meneses Martínez ◽  
Amanda Calvo ◽  
Melania Muñoz ◽  
Griselda Arrieta-Espinoza
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Costa Rica ◽  
Genetic Structure ◽  
Wild Species ◽  
Wild Rice ◽  
Wild Rice Species ◽  
Genetic Diversity And Structure ◽  
Diversity Estimates ◽  
Oryza Glumaepatula

Wild crop relatives are an important source of genetic diversity for crop improvement. However, gene flow from cultivated species into wild species may prove detrimental. Introgression may lead to changes in wild species by incorporating alleles from domesticated species, which may increase the likelihood of extinction. The objective of the present study is to analyze how genetic diversity is distributed within and among populations of the wild rice species Oryza glumaepatula in Costa Rica. We also evaluated if there is evidence of introgression between wild rice and commercial varieties of O. sativa since it is cultivated commonly in close proximity to wild rice populations. Individuals from all known O. glumaepatula populations in Costa Rica were collected. With the aid of 455 AFLP markers, we characterized the genetic diversity and structure among seven populations in northern Costa Rica. Given the dominant nature of our markers, Bayesian estimates of genetic structure were used. We also compared genetic diversity estimates between O. glumaepatula individuals and O. sativa commercial rice. Our results show that O. glumaepatula populations in Costa Rica have moderately high levels of genetic diversity, comparable to those found in South American populations. This is likely a result of large population size. Despite the restricted distributions of this wild species, in Costa Rica most populations are composed of several thousand individuals, thus reducing the effects of drift on genetic diversity. Our results also found low but significant structure (\theta=0.03±0.001) among populations that are separated by ~10 Km within a single river. The position of the population along the river did not influence genetic diversity estimates or differences among populations. This river does not have a strong current and meadows or seeds may easily move upstream, thus homogenizing genetic diversity across populations regardless of river position. Ample gene flow through pollen, seeds or detached culms within the same river reduces genetic structure. A Bayesian structure analysis showed that individuals from two populations share a significant proportion of their genomes with O. sativa genome. These results suggest that the low levels of genetic structure found in these populations are likely the result of introgression from cultivated O. sativa populations. These results expose an important biohazard as recurrent hybridization may reduce genetic diversity of this wild rice species. Introgression may transfer commercial traits into the only populations of O. glumaepatula in Costa Rica, which in turn could alter genetic diversity and increase the likelihood of local extinction. These results have important implications for in situ conservation strategies of the only wild populations of O. glumaepatula in Costa Rica.

scholarly journals De novo assembly and transcriptome characterization of an endemic species of Vietnam, Panax vietnamensis Ha et Grushv., including the development of EST-SSR markers for population genetics

2020 ◽  
Author(s):  
Duy Dinh Vu ◽  
Syed Noor Muhammad Shah ◽  
Mai Phuong Pham ◽  
Van Thang Bui ◽  
Minh Tam Nguyen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Expressed Sequence Tag ◽  
De Novo ◽  
Average Length ◽  
Species Conservation ◽  
Group Method ◽  
Arithmetic Means ◽  
Illumina Hiseq ◽  
Genetic Diversity And Structure

Abstract Background: Understanding the genetic diversity in threatened species that occur in forest remnants is necessary to establish efficient strategies for the species conservation, restoration and management. Panax vietnamensis Ha et Grushv. is medicinally important, endemic and endangered species of Vietnam. However, genetic diversity and structure of population is unknown due to lack of efficient molecular markers.Results: In this study, we employed Illumina HiSeq TM 4000 sequencing to analyze the transcriptomes of P. vietnamensis (roots, leaves and stems). A total of 23,741,783 raw reads were obtained and assembled, from which, 89,271 unigenes with an average length of 598.3191 nt were generated. During functional annotation, 31,686 unigenes were annotated in Gene Ontology categories, Kyoto Encyclopedia of Genes and Genomes pathways, Swiss-Prot database, and Nucleotide Collection (NR/NT) database. In addition, 11,343 expressed sequence tag-simple sequence repeat (EST-SSRs) were detected. From 7,774 primer pairs, 101 were selected for polymorphism validation, in which, 20 primer pairs were successfully amplified to DNA fragments and significant amounts of polymorphism was observed within population. The nine polymorphic microsatellite loci were used to analyze genetic diversity and structure of the natural populations. The obtained results revealed that the shows high levels of genetic diversity in populations, the average observed and expected heterozygosity were H O = 0.422 and H E = 0.479. During the Bottleneck analysis using TPM and SMM models (p < 0.01) shows that targeted population is significantly heterozygote deficient. This suggests sign of bottleneck in all populations. Genetic differentiation among populations was moderate (F ST = 0.133) and indicating limited gene flow (Nm = 1.63). Analysis of molecular variance (AMOVA) showed 63.17% of variation within individuals and 12.45% among populations. These results showed a moderate genetic structure of P. vietnamensis. STRUCTURE analysis and the unweighted pair-group method with arithmetic means (UPGMA) tree revealed strong genetic structure and two genetic clusters related to geographical distances, as well. Conclusion: Our study will assist conservators in future conservation management, breeding, production and habitats restoration of the species.

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