scholarly journals European Vintage tomatoes galore: a result of farmers combinatorial assorting/swapping of a few diversity rich loci

2021 ◽  
Author(s):  
Jose Blanca ◽  
Clara Pons ◽  
Javier Montero-Pau ◽  
David Sanchez-Matarredona ◽  
Peio Ziarsolo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Morphological Traits ◽  
Balancing Selection ◽  
Genotyping By Sequencing ◽  
Polymorphic Loci ◽  
Comprehensive Collection ◽  
Low Genetic Diversity ◽  
Genetic Groups ◽  
History Of ◽  
Modern Varieties

A comprehensive collection of 1,254 tomato accessions corresponding to European heirlooms and landraces, together with modern varieties, early domesticates and wild relatives, were analyzed by genotyping by sequencing. A continuous genetic gradient between the vintage and modern varieties was observed. European vintage tomatoes displayed very low genetic diversity, with only 298 loci out of 64,943 variants being polymorphic at the 95% threshold. European vintage tomatoes could be classified in several genetic groups. Two main clusters consisting of Spanish and Italian accessions showed a higher genetic diversity than the rest varieties, suggesting that these regions might be independent secondary centers of diversity and with a different history. Other varieties seem to be the result of a more recent complex pattern of migrations and hybridizations among the European regions. Several polymorphic loci were associated in a GWAS with fruit morphological traits in the European vintage collection, and the corresponding alleles were found to contribute to the distinctive phenotypic characteristic of the genetic varietal groups. The few highly polymorphic loci associated with morphological traits in an otherwise diversity-poor genome suggests a history of balancing selection, in which tomato farmers maintained the morphological variation by applying a high selective pressure within different varietal types.

Season of birth interacts with measures of inbreeding in multiplex schizophrenia pedigrees: evidence from genetic isolates in Daghestan

Open Medicine ◽  
2006 ◽  
Vol 1 (4) ◽  
pp. 392-398
Author(s):  
Kazima Bulayeva ◽  
John McGrath
Keyword(s):  
Genetic Diversity ◽  
Family History ◽  
Age Of Onset ◽  
Population Genetic Study ◽  
Season Of Birth ◽  
High Genetic Diversity ◽  
Low Genetic Diversity ◽  
High Prevalence ◽  
History Of ◽  
Genetic Isolates

AbstractWhile the season-of-birth effect is one of the most consistent epidemiological features of schizophrenia, there is a lack of consistency with respect to the interaction between season of birth and family history of schizophrenia. Apart from family history, measures related to consanguinity can be used as proxy markers of genomic heterogeneity. Thus, these measures may provide an alternate, indirect index of genetic susceptibility. We had the opportunity to explore the interaction between season of birth and measure of consanguinity in well-described genetic isolates in Daghestan, some of which are known for their relatively high prevalence of schizophrenia. Our previous population-genetic study showed Daghestan has an extremely high genetic diversity between the ethnic populations and a low genetic diversity within them. The isolates selected for this study include some with more than 200 and some with less than 100 generations of demographical history since their founding. Based on pedigrees of multiply-affected families, we found that among individuals with schizophrenia, the measure of consanguinity was significantly higher in the parents of those born in winter/spring compared to those born in summer/autumn. Furthermore, compared to summer/autumn born, winter/spring born individuals with schizophrenia had an earlier age-of-onset, and more prominent auditory hallucinations. Our results suggest that the offspring of consanguineous marriages, and thus those with reduced allelic heterogeneity, may be more susceptible to the environmental factor(s) underpinning the season-of-the effect in schizophrenia.

scholarly journals Global range expansion history of pepper (Capsicum spp.) revealed by over 10,000 genebank accessions

2021 ◽  
Vol 118 (34) ◽  
pp. e2104315118
Author(s):  
Pasquale Tripodi ◽  
Mark Timothy Rabanus-Wallace ◽  
Lorenzo Barchi ◽  
Sandip Kale ◽  
Salvatore Esposito ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genotyping By Sequencing ◽  
Focal Region ◽  
Nucleotide Polymorphisms ◽  
Trade Routes ◽  
Genebank Management ◽  
Capsicum Spp ◽  
History Of ◽  
Cultural Commodity

Genebanks collect and preserve vast collections of plants and detailed passport information, with the aim of preserving genetic diversity for conservation and breeding. Genetic characterization of such collections has the potential to elucidate the genetic histories of important crops, use marker–trait associations to identify loci controlling traits of interest, search for loci undergoing selection, and contribute to genebank management by identifying taxonomic misassignments and duplicates. We conducted a genomic scan with genotyping by sequencing (GBS) derived single nucleotide polymorphisms (SNPs) of 10,038 pepper (Capsicum spp.) accessions from worldwide genebanks and investigated the recent history of this iconic staple. Genomic data detected up to 1,618 duplicate accessions within and between genebanks and showed that taxonomic ambiguity and misclassification often involve interspecific hybrids that are difficult to classify morphologically. We deeply interrogated the genetic diversity of the commonly consumed Capsicum annuum to investigate its history, finding that the kinds of peppers collected in broad regions across the globe overlap considerably. The method ReMIXTURE—using genetic data to quantify the similarity between the complement of peppers from a focal region and those from other regions—was developed to supplement traditional population genetic analyses. The results reflect a vision of pepper as a highly desirable and tradable cultural commodity, spreading rapidly throughout the globe along major maritime and terrestrial trade routes. Marker associations and possible selective sweeps affecting traits such as pungency were observed, and these traits were shown to be distributed nonuniformly across the globe, suggesting that human preferences exerted a primary influence over domesticated pepper genetic structure.

No Evidence of Low Genetic Diversity Despite High Levels of Inbreeding and Poor Genetic Connectivity Among Tetrastigma loheri (Vitaceae) Populations in Remaining Forest Areas in Cebu, Philippines

2021 ◽  
Vol 46 (4) ◽  
pp. 951-961
Author(s):  
Jasper John A. Obico ◽  
Hemres Alburo ◽  
Julie F. Barcelona ◽  
Marie Hale ◽  
Lisa Paguntalan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Habitat Fragmentation ◽  
Tropical Forests ◽  
Forest Cover ◽  
Genetic Connectivity ◽  
Philippine Island ◽  
Low Genetic Diversity ◽  
History Of ◽  
Gap Data ◽  
The Impact

Abstract— Little is known about the effects of habitat fragmentation on the patterns of genetic diversity and genetic connectivity of species in the remaining tropical forests of Southeast Asia. This is particularly evident in Cebu, a Philippine island that has a long history of deforestation and has lost nearly all of its forest cover. To begin filling this gap, data from 13 microsatellite loci developed for Tetrastigma loheri (Vitaceae), a common vine species in Philippine forests, were used to study patterns of genetic diversity and genetic connectivity for the four largest of the remaining forest areas in Cebu. Evidence of relatively high levels of inbreeding was found in all four areas, despite no evidence of low genetic diversity. The four areas are genetically differentiated, suggesting low genetic connectivity. The presence of inbreeding and low genetic connectivity in a commonly encountered species such as T. loheri in Cebu suggests that the impact of habitat fragmentation is likely greater on rare plant species with more restricted distributions in Cebu. Conservation recommendations for the remaining forest areas in Cebu include the establishment of steppingstone corridors between nearby areas to improve the movement of pollinators and seed dispersers among them.

Comparative mitochondrial phylogeography of two legless lizards (Pygopodidae) from Queensland’s fragmented woodlands

2020 ◽  
Vol 66 (3-4) ◽  
pp. 142-150
Author(s):  
Jessica Worthington Wilmer ◽  
Andrew P. Amey ◽  
Carmel McDougall ◽  
Melanie Venz ◽  
Stephen Peck ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Evolutionary History ◽  
The West ◽  
European Settlement ◽  
Low Genetic Diversity ◽  
Eastern Australia ◽  
Wide Range ◽  
History Of ◽  
Open Forests ◽  
Fossorial Species

Sclerophyll woodlands and open forests once covered vast areas of eastern Australia, but have been greatly fragmented and reduced in extent since European settlement. The biogeographic and evolutionary history of the biota of eastern Australia’s woodlands also remains poorly known, especially when compared to rainforests to the east, or the arid biome to the west. Here we present an analysis of patterns of mitochondrial genetic diversity in two species of Pygopodid geckos with distributions centred on the Brigalow Belt Bioregion of eastern Queensland. One moderately large and semi-arboreal species, Paradelma orientalis, shows low genetic diversity and no clear geographic structuring across its wide range. In contrast a small and semi-fossorial species, Delma torquata, consists of two moderately divergent clades, one from the ranges and upland of coastal areas of south-east Queensland, and other centred in upland areas further inland. These data point to varying histories of geneflow and refugial persistance in eastern Australia’s vast but now fragmented open woodlands. The Carnarvon Ranges of central Queensland are also highlighted as a zone of persistence for cool and/or wet-adapted taxa, however the evolutionary history and divergence of most outlying populations in these mountains remains unstudied.

scholarly journals Evolution of the U.S. Biological Select AgentRathayibacter toxicus

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Edward W. Davis ◽  
Javier F. Tabima ◽  
Alexandra J. Weisberg ◽  
Lucas Dantas Lopes ◽  
Michele S. Wiseman ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Adaptive Immune System ◽  
The United States ◽  
Genomic Diversity ◽  
Data Set ◽  
Important Species ◽  
Content Type ◽  
Low Genetic Diversity ◽  
History Of ◽  
Short Palindromic Repeat

ABSTRACTRathayibacter toxicusis a species of Gram-positive, corynetoxin-producing bacteria that causes annual ryegrass toxicity, a disease often fatal to grazing animals. A phylogenomic approach was employed to model the evolution ofR. toxicusto explain the low genetic diversity observed among isolates collected during a 30-year period of sampling in three regions of Australia, gain insight into the taxonomy ofRathayibacter, and provide a framework for studying these bacteria. Analyses of a data set of more than 100 sequencedRathayibactergenomes indicated thatRathayibacterforms nine species-level groups.R. toxicusis the most genetically distant, and evidence suggested that this species experienced a dramatic event in its evolution. Its genome is significantly reduced in size but is colinear to those of sister species. Moreover,R. toxicushas low intergroup genomic diversity and almost no intragroup genomic diversity between ecologically separated isolates.R. toxicusis the only species of the genus that encodes a clustered regularly interspaced short palindromic repeat (CRISPR) locus and that is known to host a bacteriophage parasite. The spacers, which represent a chronological history of infections, were characterized for information on past events. We propose a three-stage process that emphasizes the importance of the bacteriophage and CRISPR in the genome reduction and low genetic diversity of theR. toxicusspecies.IMPORTANCERathayibacter toxicusis a toxin-producing species found in Australia and is often fatal to grazing animals. The threat of introduction of the species into the United States led to its inclusion in the Federal Select Agent Program, which makesR. toxicusa highly regulated species. This work provides novel insights into the evolution ofR. toxicus.R. toxicusis the only species in the genus to have acquired a CRISPR adaptive immune system to protect against bacteriophages. Results suggest that coexistence with the bacteriophage NCPPB3778 led to the massive shrinkage of theR. toxicusgenome, species divergence, and the maintenance of low genetic diversity in extant bacterial groups. This work contributes to an understanding of the evolution and ecology of an agriculturally important species of bacteria.

scholarly journals Populations of Phytophthora rubi Show Little Differentiation and High Rates of Migration Among States in the Western United States

2018 ◽  
Vol 31 (6) ◽  
pp. 614-622 ◽  
Author(s):  
Javier F. Tabima ◽  
Michael D. Coffey ◽  
Inga A. Zazada ◽  
Niklaus J. Grünwald
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Root Rot ◽  
Genotyping By Sequencing ◽  
The United States ◽  
Western United States ◽  
Lineage Sorting ◽  
Phytophthora Root Rot ◽  
Agricultural Ecosystems ◽  
Low Genetic Diversity

Population genetics is a powerful tool to understand patterns and evolutionary processes that are involved in plant-pathogen emergence and adaptation to agricultural ecosystems. We are interested in studying the population dynamics of Phytophthora rubi, the causal agent of Phytophthora root rot in raspberry. P. rubi is found in the western United States, where most of the fresh and processed raspberries are produced. We used genotyping-by-sequencing to characterize genetic diversity in populations of P. rubi sampled in the United States and other countries. Our results confirm that P. rubi is a monophyletic species with complete lineage sorting from its sister taxon P. fragariae. Overall, populations of P. rubi show low genetic diversity across the western United States. Demographic analyses suggest that populations of P. rubi from the western United States are the source of pathogen migration to Europe. We found no evidence for population differentiation at a global or regional (western United States) level. Finally, our results provide evidence of migration from California and Oregon into Washington. This report provides new insights into the evolution and structure of global and western United States populations of the raspberry pathogen P. rubi, indicating that human activity might be involved in moving the pathogen among regions and fields.

scholarly journals Utilization of Molecular Marker Based Genetic Diversity Patterns in Hybrid Parents to Develop Better Forage Quality Multi-Cut Hybrids in Pearl Millet

Agriculture ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 97 ◽  
Author(s):  
Govintharaj Ponnaiah ◽  
Shashi Kumar Gupta ◽  
Michael Blümmel ◽  
Maheswaran Marappa ◽  
Sumathi Pichaikannu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Pearl Millet ◽  
Morphological Traits ◽  
Forage Quality ◽  
Genotyping By Sequencing ◽  
Single Nucleotide ◽  
Breeding Programs ◽  
Clear Cut

Genetic diversity of 130 forage-type hybrid parents of pearl millet was investigated based on multiple season data of morphological traits and two type of markers: SSRs (Simple sequence repeats) and GBS identified SNPs (Genotyping by sequencing-Single nucleotide polymorphism). Most of the seed and pollinator parents clustered into two clear-cut separate groups based on marker based genetic distance. Significant variations were found for forage related morphological traits at different cutting intervals (first and second cut) in hybrid parents. Across two cuts, crude protein (CP) varied from 11% to 15%, while in vitro organic matter digestibility (IVOMD) varied from 51% to 56%. Eighty hybrids evaluated in multi-location trial along with their parents for forage traits showed that significant heterosis can be realized for forage traits. A low but positive significant correlation found between SSR based genetic distance (GD between parents of hybrid) and heterosis for most of the forage traits indicated that SSR-based GD can be used for predicting heterosis for GFY, DFY and CP in pearl millet. An attempt was made to associate marker-based clusters with forage quality traits, to enable breeders select parents for crossing purposes in forage breeding programs.

scholarly journals Low Genetic Diversity in Wide-Spread Eurasian Liver Fluke Opisthorchis felineus Suggests Special Demographic History of This Trematode Species

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e62453 ◽  
Author(s):  
Ilja I. Brusentsov ◽  
Alexey V. Katokhin ◽  
Irina V. Brusentsova ◽  
Sergei V. Shekhovtsov ◽  
Sergei N. Borovikov ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Liver Fluke ◽  
Demographic History ◽  
Trematode Species ◽  
Wide Spread ◽  
Opisthorchis Felineus ◽  
Low Genetic Diversity ◽  
History Of

scholarly journals Mitochondrial DNA Phylogenetics of Black Rhinoceros in Kenya in relation to Southern Africa Population

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Elijah K. Githui ◽  
David N. Thuo ◽  
Joshua O. Amimo ◽  
Nyamu M. Njagi ◽  
Maryanne M. Gitari
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Southern Africa ◽  
Wildlife Conservation ◽  
Eastern Africa ◽  
Black Rhinoceros ◽  
Low Genetic Diversity ◽  
History Of ◽  
Eastern And Southern Africa ◽  
Game Hunting

Black rhinoceros (Diceros bicornis) are highly endangered due to poaching and other anthropological reasons and their protection to rebound the numbers and genetic improvement are necessary remedial measures defined by Rhino International Union of Conservation for the Nature Red List (IUCN). In Kenya black rhino numbers declined from approximately 20,000 in the 1970s to fewer than 400 in 1982. Wildlife conservation managers effected strategies to manage/breed the remaining rhinoceros populations in Eastern and Southern Africa within regional sanctuaries. This study analyzes the genetic variability of these remnant rhinoceros using Mitochondrial DNA (mtDNA). Majority of the rhinoceros in both Kenyan and Southern Africa group are monophyletic clusters with insignificant genetic variations while some lineages are underrepresented. The Eastern Africa rhinoceros forms a distinct clade from the Sothern Africa counterpart while Tanzania population has admixtures. Tajima-D test showed that these two populations are under different selection pressure possibly due to different history of adverse anthropologic activities. Similarly, the Southern Africa rhinoceros have low genetic diversity compared to the Eastern African population due to extended periods of game hunting during Africa colonization. This study suggests that managed translocations of individual rhinoceros across the separated fragments can be applied to improve their genetic diversity.

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