Diversity and genetic structure of cassava landraces and their wild relatives (Manihot spp.) in Colombia revealed by simple sequence repeats

2015 ◽  
Vol 14 (3) ◽  
pp. 200-210 ◽  
Author(s):  
E. Tovar ◽  
J. L. Bocanegra ◽  
C. Villafañe ◽  
L. Fory ◽  
A. Velásquez ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Resources ◽  
Wild Relatives ◽  
Targeted Interventions ◽  
Genetic Diversity And Structure ◽  
Baseline Information ◽  
Cultivated Species ◽  
Simple Sequence

Understanding the genetic composition and population structure of plant species at a molecular level is essential for the development of adequate strategies aimed at enhancing the conservation and use of their genetic resources. In addition, such knowledge can help to plan ahead for a scenario under which wild and cultivated species come into contact with their genetically modified (GM) counterpart(s). Using ten simple sequence repeat markers, we genotyped 409 samples pertaining to the species in the Manihot genus known to occur in Colombia, i.e. cassava (Manihot esculenta) and its wild relatives Manihot brachyloba, Manihot carthaginensis and Manihot tristis. High genetic variation was observed in all the species (HE= 0.212–0.603), with cassava showing highest diversity. Most of the genetic variation was found within species populations. Our results suggest that outcrossing events among populations occur much more frequently in M. tristis and M. esculenta, and particularly so in the latter, where the exchange of varieties among local farmers plays a key role in maintaining and introducing new genetic diversity. The occurrence of gene flow within and among populations of Manihot species in Colombia becomes relevant in a biosafety context, where gene flow from GM cassava, if introduced to the country, might have detrimental effects on the structure and dynamics of populations of wild species. The baseline information on the genetic diversity and structure of the four Colombian species that we have presented here provides a first and indispensable step towards the development of targeted interventions necessary to preserve their genetic resources.

scholarly journals Spatial and temporal genetic variation in Ethiopian barley (Hordeum vulgare L.) landraces as revealed by simple sequence repeat (SSR) markers

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Allo A. Dido ◽  
Dawit T. Degefu ◽  
Ermias Assefa ◽  
M. S. R. Krishna ◽  
B. J. K. Singh ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Hordeum Vulgare ◽  
Simple Sequence Repeat ◽  
Environmental Changes ◽  
Future Climate Change ◽  
Sequence Repeat ◽  
Simple Sequence ◽  
Temporal Genetic Variation

Abstract Background Ethiopia is considered as center of diversity for barley (Hordeum vulgare L.) and it is grown across different agro-ecologies of the country. Unraveling population structure and gene flow status on temporal scales assists an evaluation of the consequences of physical, demographic and overall environmental changes on the stability and persistence of populations. This study was to examine spatial and temporal genetic variation within and among barley landrace samples collected over a period of four decades, using simple sequence repeat markers. Results Results from STRUCTURE, neighbor joining tree and discriminant analysis of principal component (DAPC) analysis revealed presence low-to-high genetic diversity among the landraces and grouped the landraces into three clusters. The cluster analysis revealed a close relationship between landraces along geographic proximity with genetic distance increases along with geographic distance. From analysis of molecular variance (AMOVA) in terms of collection year, it was observed that within-population genetic diversity much higher than between population and that the temporal differentiation is considerably smaller. The low-to-high genetic differentiation between landraces could be attributed to gene flow across the region as a consequence of seed exchange among farmers. Conclusion The results demonstrate that this set of SSRs was highly informative and useful in generating a meaningful classification of barley germplasms. Furthermore, results obtained from this study also suggest that landraces are a source of valuable germplasm for sustainable agriculture in the context of future climate change and in situ conservation strategies following adaptation to local environments.

scholarly journals Genetic diversity and structure of Musa balbisiana populations in Vietnam and its implications for the conservation of banana crop wild relatives

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253255
Author(s):  
Arne Mertens ◽  
Yves Bawin ◽  
Samuel Vanden Abeele ◽  
Simon Kallow ◽  
Dang Toan Vu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Crop Wild Relatives ◽  
Wild Relatives ◽  
Distribution Area ◽  
Mountain Range ◽  
Musa Balbisiana ◽  
Northern Vietnam ◽  
Central Vietnam ◽  
Genetic Diversity And Structure

Crop wild relatives (CWR) are an indispensable source of alleles to improve desired traits in related crops. While knowledge on the genetic diversity of CWR can facilitate breeding and conservation strategies, it has poorly been assessed. Cultivated bananas are a major part of the diet and income of hundreds of millions of people and can be considered as one of the most important fruits worldwide. Here, we assessed the genetic diversity and structure of Musa balbisiana, an important CWR of plantains, dessert and cooking bananas. Musa balbisiana has its origin in subtropical and tropical broadleaf forests of northern Indo-Burma. This includes a large part of northern Vietnam where until now, no populations have been sampled. We screened the genetic variation and structure present within and between 17 Vietnamese populations and six from China using 18 polymorphic SSR markers. Relatively high variation was found in populations from China and central Vietnam. Populations from northern Vietnam showed varying levels of genetic variation, with low variation in populations near the Red River. Low genetic variation was found in populations of southern Vietnam. Analyses of population structure revealed that populations of northern Vietnam formed a distinct genetic cluster from populations sampled in China. Together with populations of central Vietnam, populations from northern Vietnam could be subdivided into five clusters, likely caused by mountain ranges and connected river systems. We propose that populations sampled in central Vietnam and on the western side of the Hoang Lien Son mountain range in northern Vietnam belong to the native distribution area and should be prioritised for conservation. Southern range edge populations in central Vietnam had especially high genetic diversity, with a high number of unique alleles and might be connected with core populations in northern Laos and southwest China. Southern Vietnamese populations are considered imported and not native.

scholarly journals Genetic diversity and phenetic relationships of five Trifolium L. species (Fabaceae) by inter simple sequence repeats markers

2016 ◽  
Vol 23 (2) ◽  
pp. 167-173
Author(s):  
Yourang Hwang ◽  
Man Kyu Huh
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Simple Sequence Repeats ◽  
Issr Markers ◽  
Phenetic Relationships ◽  
Inter Simple Sequence Repeats ◽  
Total Genetic Diversity ◽  
Plant Taxon ◽  
Simple Sequence

Five species of Trifolium L. (T. repens L., T. pretense L., T. hybridum L., T. campestre Schreb., and T. dubium Sibth.) were analyzed used to evaluate the genetic diversity and their phenetic relationships using inter-simple sequence repeats (ISSR) markers. Overall, T. pratense exhibited higher variation than other species. 114 amplicons were produced by ISSR markers, of which 77 (67.5%) bands were polymorphic. T. dubium showed the low genetic variation. Total genetic diversity values (HT) varied between 0.333 and 0.487, for an average over all polymorphic loci of 0.282. On a perlocus basis, the proportion of total genetic variation due to differences among species (GST) was 0.380. This indicated that about 38.0% of the total variation was among species. The estimate of gene flow, based on GST, was very low among species of genus Trifolium (Nm = 0.816). An assessment of the proportion of diversity present within species, HPOP/HSP, indicated that about 95.8% the total genetic diversity was within species. T. pratense and T. hybridum were grouped together and this clade was sister with T. repens. Two remainder species with yellow flowers were grouped together. Information on genetic diversity for Trifolium is valued for the management of germplasm and for evolving conservation strategies.Bangladesh J. Plant Taxon. 23(2): 167-173, 2016 (December)

Population Genetic Diversity and Structure of Thrips tabaci (Thysanoptera: Thripidae) on Allium Hosts in China, Inferred From Mitochondrial COI Gene Sequences

2020 ◽  
Vol 113 (3) ◽  
pp. 1426-1435
Author(s):  
Xiaowei Li ◽  
Zhijun Zhang ◽  
Jinming Zhang ◽  
Jun Huang ◽  
Likun Wang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Human Activities ◽  
Population Genetic ◽  
Thrips Tabaci ◽  
Tibet Plateau ◽  
Geographic Locations ◽  
Genetic Diversity And Structure ◽  
Geographical Distances

Abstract Thrips tabaci Lindeman is a widely distributed agricultural pest China, which causes damage to many vegetables and cash crops. However, the population genetic variation of this pest in China remains unknown. In this study, the genetic diversity and structure of T. tabaci on Allium hosts collected from 12 geographic locations were evaluated based on mitochondrial cytochrome oxidase subunit I (COI) sequences. Six haplotypes were identified in 247 T. tabaci individuals from 12 geographic locations. All the identified T. tabaci haplotypes were thelytokous populations. The strongest genetic differentiation and relatively low gene flow were found between QHXN and other locations, which might be due to geographic barriers, such as high altitude Qinghai-Tibet Plateau. The lowest genetic variation was found in eastern and southern regions, with only one haplotype identified. The Mantel test showed no correlation between genetic distance and geographical distances. High gene flow between locations with substantial geographical distances suggested that migration of T. tabaci across China might be facilitated through human activities. The results of demographic analysis suggested that T. tabaci in China have undergone a recent demographic expansion. The possible influences of T. tabaci invasion history and human activities on the current haplotype geographical distribution were interpreted and the implications of these findings for T. tabaci management were discussed.

scholarly journals Targeted Sequencing Suggests Wild-Crop Gene Flow Is Central to Different Genetic Consequences of Two Independent Pumpkin Domestications

2021 ◽  
Vol 9 ◽  
Author(s):  
Heather R. Kates ◽  
Fernando López Anido ◽  
Guillermo Sánchez-de la Vega ◽  
Luis E. Eguiarte ◽  
Pamela S. Soltis ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Structure ◽  
Morphological Diversity ◽  
Cucurbita Maxima ◽  
Wild Progenitor ◽  
Breeding Potential ◽  
Trait Improvement ◽  
Wild Progenitors

Studies of domestication genetics enrich our understanding of how domestication shapes genetic and morphological diversity. We characterized patterns of genetic variation in two independently domesticated pumpkins and their wild progenitors to assess and compare genetic consequences of domestication. To compare genetic diversity pre- and post-domestication and to identify genes targeted by selection during domestication, we analyzed ∼15,000 SNPs of 48 unrelated accessions, including wild, landrace, and improved lines for each of two pumpkin species, Cucurbita argyrosperma and Cucurbita maxima. Genetic diversity relative to its wild progenitor was reduced in only one domesticated subspecies, C. argyrosperma ssp. argyrosperma. The two species have different patterns of genetic structure across domestication status. Only 1.5% of the domestication features identified for both species were shared between species. These findings suggest that ancestral genetic diversity, wild-crop gene flow, and domestication practices shaped the genetic diversity of two similar Cucurbita crops in different ways, adding to our understanding of how genetic diversity changes during the processes of domestication and how trait improvement impacts the breeding potential of modern crops.

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 Genetic Structure and Eco-Geographical Differentiation of Lancea tibetica in the Qinghai-Tibetan Plateau

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 97 ◽  
Author(s):  
Xiaofeng Chi ◽  
Faqi Zhang ◽  
Qingbo Gao ◽  
Rui Xing ◽  
Shilong Chen
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Gene Flow ◽  
Tibetan Plateau ◽  
Environmental Changes ◽  
Restricted Gene Flow ◽  
Principal Coordinates Analysis ◽  
Principal Coordinates ◽  
Genetic Diversity And Structure ◽  
Tanggula Mountains

The uplift of the Qinghai-Tibetan Plateau (QTP) had a profound impact on the plant speciation rate and genetic diversity. High genetic diversity ensures that species can survive and adapt in the face of geographical and environmental changes. The Tanggula Mountains, located in the central of the QTP, have unique geographical significance. The aim of this study was to investigate the effect of the Tanggula Mountains as a geographical barrier on plant genetic diversity and structure by using Lancea tibetica. A total of 456 individuals from 31 populations were analyzed using eight pairs of microsatellite makers. The total number of alleles was 55 and the number per locus ranged from 3 to 11 with an average of 6.875. The polymorphism information content (PIC) values ranged from 0.2693 to 0.7761 with an average of 0.4378 indicating that the eight microsatellite makers were efficient for distinguishing genotypes. Furthermore, the observed heterozygosity (Ho), the expected heterozygosity (He), and the Shannon information index (I) were 0.5277, 0.4949, and 0.9394, respectively, which indicated a high level of genetic diversity. We detected high genetic differentiation among all sampling sites and restricted gene flow among populations. Bayesian-based cluster analysis (STRUCTURE), principal coordinates analysis (PCoA), and Neighbor-Joining (NJ) cluster analysis based on microsatellite markers grouped the populations into two clusters: the southern branch and the northern branch. The analysis also detected genetic barriers and restricted gene flow between the two groups separated by the Tanggula Mountains. This study indicates that the geographical isolation of the Tanggula Mountains restricted the genetic connection and the distinct niches on the two sides of the mountains increased the intraspecific divergence of the plants.

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