scholarly journals Management Practices and Breeding History of Varieties Strongly Determine the Fine Genetic Structure of Crop Populations: A Case Study Based on European Wheat Populations

2020 ◽  
Vol 12 (2) ◽  
pp. 613
Author(s):  
Abdul Rehman Khan ◽  
Isabelle Goldringer ◽  
Mathieu Thomas
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Management Practices ◽  
Genetic Group ◽  
Ex Situ ◽  
History Of ◽  
Breeding History ◽  
On Farm ◽  
Different Levels

As the effects of climate change begin to be felt on yield stability, it is becoming essential to promote the use of genetic diversity in farmers’ fields. The presence of genetic variability in variety could fulfil this purpose. Indeed, the level of intra-varietal genetic diversity influences the spatio-temporal stability of yields and the disease susceptibility of crop species. Breeding history of varieties and their management practices are two factors that should influence intra-varietal genetic diversity. This paper describes the genetic diversity of eight wheat samples covering a gradient from modern single varieties to on-farm mixtures of landraces. This gradient discriminates between landrace, historical and modern varieties, considering the breeding history of varieties, between single-varieties and mixtures of varieties, and between ex situ and in situ de facto strategy in terms of management practices. Genetic diversity of these samples was analyzed with the help of 41 single nucleotide polymorphism markers located in neutral regions, through computing genetic indices at three different levels: Allelic, haplotypic and genetic group level. Population structure and kinship were depicted using discriminant analysis and kinship network analysis. Results revealed an increase in the complexity of the genetic structure as we move on the gradient of variety types (from modern single variety to in situ on-farm mixtures of landraces). For the landraces, the highest levels of genetic diversity have been observed for a landrace (Solina d’Abruzzo) continuously grown on-farm in the region of Abruzzo, in Italy, for many decades. This landrace showed an excess of haplotypic diversity compared to landraces or the historical variety that were stored in genebanks (ex situ conservation). Genetic analyses of the mixtures revealed that, despite a very high selfing rate in wheat, growing in evolutionary mixtures promotes recombination between different genetic components of the mixture, a second way to increase the level of haplotype diversity. When management practices such as growing in mixture and on-farm management are combined, they substantially increase the different levels of genetic diversity of the populations (allelic, haplotypic, genetic group diversity), and consequently promote their adaptability. Our results confirm the need to develop and manage evolving diversified large populations on-farm. These results invite crop diversity managers such as genebank curators, community seed bank managers and farmers’ organizations to adapt their management strategies to the type of variety they wish to manage, because we have shown that their choices have a strong influence on the genetic composition of the crop populations.

scholarly journals Drilling down hotspots of intraspecific diversity to bring them into on-ground conservation of threatened species

2018 ◽  
Author(s):  
Mauro Zampiglia ◽  
Roberta Bisconti ◽  
Luigi Maiorano ◽  
Gaetano Aloise ◽  
Antonino Siclari ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Threatened Species ◽  
Management Practices ◽  
In Situ Conservation ◽  
Intraspecific Diversity ◽  
Ex Situ ◽  
Spatial And Temporal Variation ◽  
Conservation Priorities ◽  
Global Changes

AbstractUnprecedented rates of biodiversity loss rise the urgency for preserving species ability to cope with ongoing global changes. An approach in this direction is to target intra-specific hotspots of genetic diversity as conservation priorities. However, these hotspots are often identified by sampling at a spatial resolution too coarse to be useful in practical management of threatened species, hindering the long-appealed dialog between conservation stakeholders and conservation genetic researchers. Here, we investigated the spatial and temporal variation in species presence, genetic diversity, as well as potential risk factors, within a previously identified hotspot of genetic diversity for the endangered Apennine yellow bellied toad Bombina pachypus. Our results show that this hotspot is neither a geographically homogeneous nor a temporally stable unit. Over a time-window spanning 10-40 years since previous assessments, B. pachypus populations declined in large portions of its hotspot, and their genetic diversity levels decreased. Considering the demographic trend, genetic and epidemiological data, and models of current and future climatic suitability, populations at the extreme south of the hotspot area still qualify for urgent in-situ conservation actions, whereas northern populations would be better managed through a mix of in-situ and ex-situ actions. Our results emphasize that identifying hotspot of genetic diversity, albeit essential step, does not suffice to warrant on-ground conservation of threatened species. Hotspots should be analysed at finer geographic and temporal scales, to provide conservation stakeholders with key knowledge to best define conservation priorities, and to optimize resource allocation to alternative management practices.

scholarly journals Genetic diversity and population structure of the endangered basal angiospermBrasenia schreberi(Cabombaceae) in China

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5296 ◽  
Author(s):  
Zhi-Zhong Li ◽  
Andrew W. Gichira ◽  
Qing-Feng Wang ◽  
Jin-Ming Chen
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Habitat Fragmentation ◽  
Glacial Refugia ◽  
Mantel Test ◽  
Ex Situ ◽  
Brasenia Schreberi ◽  
Genetic Diversity And Structure ◽  
Rare And Endangered

Brasenia schreberiJ.F. Gmelin (Cabombaceae), an aquatic herb that occurs in fragmented locations in China, is rare and endangered. Understanding its genetic diversity and structure is crucial for its conservation and management. In this study, 12 microsatellite markers were used to estimate the genetic diversity and variation in 21 populations ofB. schreberiin China. A total of 61 alleles were found; assessment of allelic richness (Ar = 1.92) and observed and expected heterozygosity (HO= 0.200,HE= 0.256) suggest lower genetic diversity compared to some endangered species, and higher variation was observed within populations (58.68%) rather than among populations (41.32%). No significant correlation between geographical and genetic distance among populations was detected (Mantel test,r= 0.0694;P= 0.7985), which may have likely resulted from barriers to gene flow (Nm = 0.361) that were produced by habitat fragmentation. However, Bayesian and neighbor-joining cluster analyses suggest a population genetic structure consisting of two clusters (I and II) or four subclusters (I-1, 2 and II-1, 2). The genetic structure and distribution ofB. schreberiin China may have involved glacial refugia that underwent range expansions, introgression, and habitat fragmentation. The findings of the present study emphasize the importance for both in situ and ex situ conservation efforts.

scholarly journals New insights on spatial genetic structure and diversity of Coffea canephora (Rubiaceae) in Upper Guinea based on old herbaria

2020 ◽  
Vol 153 (1) ◽  
pp. 82-100
Author(s):  
Jean-Pierre Labouisse ◽  
Philippe Cubry ◽  
Frédéric Austerlitz ◽  
Ronan Rivallan ◽  
Hong Anh Nguyen
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Coffea Canephora ◽  
Ex Situ ◽  
Herbarium Specimens ◽  
Robusta Coffee ◽  
Forest Remnants ◽  
History Of ◽  
Genetic Structure And Diversity

Backgrounds and aims – Previous studies showed that robusta coffee (Coffea canephora Pierre ex A.Froehner), one of the two cultivated coffee species worldwide, can be classified in two genetic groups: the Guinean group originating in Upper Guinea and the Congolese group in Lower Guinea and Congolia. Although C. canephora of the Guinean group is an important resource for genetic improvement of robusta coffee, its germplasm is under-represented in ex situ gene banks and its genetic diversity and population structure have not yet been investigated. Methods – To overcome the limitations of living collections, we explored old herbarium specimens collected in Guinea and Côte d’Ivoire and conserved at the Muséum National d’Histoire Naturelle, Paris. First, we reviewed the history of collection missions in both countries and how the C. canephora herbaria from the Muséum were assembled. Then, using 23 nuclear microsatellite markers, factorial and model-based Bayesian analyses, we investigated the genetic diversity of 126 specimens and 36 controls, analysed their distribution among the Congolese and Guinean groups, and estimated admixture proportions for each individual.Key results – For the first time, we detected population genetic structure within the Guinean group of C. canephora. The Guinean genotypes can be assigned to five sub-groups with distinct geographic distribution, especially in Guinea where two sub-groups (Maclaudii and Gamé) are characterized by a low level of admixture due to geographical isolation.Conclusions – We showed how combining a literature review and genetic data from old herbarium specimens can shed light on previous observations made by botanists and guide further actions to better preserve native coffee plants in forest remnants of West Africa.

scholarly journals The merger-driven evolution of massive early-type galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 62-66
Author(s):  
Carlo Cannarozzo ◽  
Carlo Nipoti ◽  
Alessandro Sonnenfeld ◽  
Alexie Leauthaud ◽  
Song Huang ◽  
...  
Keyword(s):  
Mass Velocity ◽  
Selection Criteria ◽  
Velocity Dispersion ◽  
Ex Situ ◽  
Scaling Relations ◽  
Early Type ◽  
History Of ◽  
Kinematic Properties ◽  
Shed Light

AbstractThe evolution of the structural and kinematic properties of early-type galaxies (ETGs), their scaling relations, as well as their stellar metallicity and age contain precious information on the assembly history of these systems. We present results on the evolution of the stellar mass-velocity dispersion relation of ETGs, focusing in particular on the effects of some selection criteria used to define ETGs. We also try to shed light on the role that in-situ and ex-situ stellar populations have in massive ETGs, providing a possible explanation of the observed metallicity distributions.

Genetic diversity and breeding history of Winter Mushroom (Flammulina velutipes) in China uncovered by genomic SSR markers

Gene ◽  
2016 ◽  
Vol 591 (1) ◽  
pp. 227-235 ◽  
Author(s):  
Xiao Bin Liu ◽  
Bang Feng ◽  
Jing Li ◽  
Chen Yan ◽  
Zhu L. Yang
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Flammulina Velutipes ◽  
Genomic Ssr ◽  
History Of ◽  
Breeding History

Soil seed bank and vegetation dynamics in Sahelian fallows; the impact of past cropping and current grazing treatments

2004 ◽  
Vol 20 (6) ◽  
pp. 683-691 ◽  
Author(s):  
Bruno Hérault ◽  
Pierre Hiernaux
Keyword(s):  
Seed Bank ◽  
Management Practices ◽  
Soil Seed Bank ◽  
Residual Effects ◽  
Ex Situ ◽  
Phosphorus Fertilizer ◽  
Wet Season ◽  
Seed Extraction ◽  
The Impact

The soil seed bank in a 5-y-old Sahelian fallow was studied through seed extraction and compared with germinations recorded either in controlled conditions, ex situ in a glasshouse, or in the field. The influence of phosphorus fertilizer and mulch application during the preceding crop period, and that of seasonal grazing regimes applied the last 2 y of fallowing, were assessed on the composition of the seed stock. Ctenium elegans, Fimbristylis hispidula, Merremia pinnata and Phyllanthus pentandrus accounted together for 75% of extracted seeds, 72% of ex situ, and 62% of in situ seedlings. Mulch treatment was correlated with the first axis of the canonical correspondence analyses performed on the seedling datasets. Mulch and phosphorus fertilizer treatments held similar responses, as they both favoured the seed bank of erect dicotyledons such as P. pentandrus and Cassia mimosoides. On the whole, the effects of grazing remained modest compared with the residual effects of past crop management practices. However, seedling densities increased as a result of dry-season grazing, while the soil seed bank decreased with wet-season grazing. Grazing also reduced the spatial heterogeneity of the seed bank rather than the overall number of species.

scholarly journals AUTOCHTHONOUS BREEDS OF DOMESTIC ANIMALS AND CONSERVATION MEASURES

AGROFOR ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Zoran MALETIC
Keyword(s):  
Genetic Diversity ◽  
Biological Diversity ◽  
Domestic Animals ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Animal Genetic Resources ◽  
Diversity Preservation ◽  
The Republic ◽  
International Conventions

Recently, highly productive breeds of various species of domestic animals have been used in livestock production, which has resulted in the destruction of indigenous breeds of domestic animals around the world, even in our area. This is the first reason why indigenous races and strains have been endangered. Another reason is that domestic, indigenous breeds were crossed with specialized breeds, which were imported, and in that way their genetic diversity was negatively affected. Resistance is lost, adaptation to the conditions in which they were created, the ability to survive in nature. Indigenous breeds of different species of domestic animals, which are recognized in the Republic of Srpska (BiH) are gatačko cattle and buša (cattle), Vlašić pramenka, Podveleška pramenka, Kupres pramenka (sheep), domestic Balkan horned goat (goats), Bosnian mountain horse (horses), mangulica (pigs) and pogrmuša hen or živičarka hen (poultry). By acceding to international conventions, BiH /Republic of Srpska has committed itself to establishing a system of measures that will enable the conservation of biological diversity and the protection of indigenous and endangered breeds of domestic animals. The choice of a strategy for the conservation of diversity, the establishment of an adequate conservation scheme, and the implementation of a conservation strategy are some of the key elements of any process for the conservation of genetic diversity. Preservation of autochthonous and protected breeds of domestic animals is possible through preservation in the original environment (in situ) and preservation outside the original environment (ex situ). There is a possibility of combining these models of conservation of animal genetic resources.

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.

Genetic diversity, core collection and breeding history of Pleurotus ostreatus in China

Mycoscience ◽  
2019 ◽  
Vol 60 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Jing Li ◽  
Xiao-Bin Liu ◽  
Zhi-Wei Zhao ◽  
Zhu L. Yang
Keyword(s):  
Genetic Diversity ◽  
Pleurotus Ostreatus ◽  
Core Collection ◽  
History Of ◽  
Breeding History

scholarly journals Population Genetic Structure and Genetic Diversity in Twisted-Jaw Fish, Belodontichthys truncatus Kottelat & Ng, 1999 (Siluriformes: Siluridae), from Mekong Basin

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Surapon Yodsiri ◽  
Komgrit Wongpakam ◽  
Adisak Ardharn ◽  
Chadaporn Senakun ◽  
Sutthira Khumkratok
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Demographic History ◽  
Hydropower Plant ◽  
Mekong River ◽  
Demographic Expansion ◽  
High Genetic Diversity ◽  
History Analysis ◽  
History Of ◽  
Important Food Source

The Mekong River and its tributaries possess the second highest diversity in fish species in the world. However, the fish biodiversity in this river is threatened by several human activities, such as hydropower plant construction. Understanding the genetic diversity and genetic structure of the species is important for natural resource management. Belodontichthys truncatus Kottelat & Ng is endemic to the Mekong River basin and is an important food source for people in this area. In this study, the genetic diversity, genetic structure, and demographic history of the twisted-jaw fish, B. truncatus, were investigated using mitochondrial cytochrome b gene sequences. A total of 124 fish specimens were collected from 10 locations in the Mekong and its tributaries. Relatively high genetic diversity was found in populations of B. truncatus compared to other catfish species in the Mekong River. The genetic structure analysis revealed that a population from the Chi River in Thailand was genetically significantly different from other populations, which is possibly due to the effect of genetic drift. Demographic history analysis indicated that B. truncatus has undergone recent demographic expansion dating back to the end of the Pleistocene glaciation.

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