Assessing and Managing Man's Impact on Fish Genetic Resources

1981 ◽  
Vol 38 (12) ◽  
pp. 1899-1907 ◽  
Author(s):  
J. E. Thorpe ◽  
J. F. Koonce ◽  
D. Borgeson ◽  
B. Henderson ◽  
A. Lamsa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Human Activities ◽  
Genetic Basis ◽  
Genetic Change ◽  
Stock Structure ◽  
Genetic Composition ◽  
Juvenile Period ◽  
Selection Gene ◽  
The Relationship

Historically, human activities have adversely affected the genetic resources of many fish species. We suggest that a continuum of vulnerability to loss of genetic resources exists for fishes. Primary determinants of vulnerability are extent of stock structure in populations and fundamental life history features, such as length of juvenile period, sex ratio, and fecundity. The genetic basis for this trend is the relationship between the subdivided state of a population (its stock structure) and important processes of genetic change, which include selection, gene flow, and genetic drift. We relate various human activities to their effects on genetic resources through these genetic processes, and we review various lines of evidence for a relationship between stock structure and genetic diversity. In general, we found that those species whose populations are subdivided into nearly isolated stocks (e.g. Pacific and Atlantic salmon) are more vulnerable to directional changes in genetic composition as well as reduction in overall genetic diversity through loss of some stocks. We also found that similar changes will be difficult to detect, if they occur at all, in less stock-structured species like walleye.Key words: stock structure, genetic diversity

Genetic diversity of native cultivated cacao accessions (Theobroma cacao L.) in Nicaragua

2012 ◽  
Vol 10 (3) ◽  
pp. 254-257
Author(s):  
Erwin Aragon ◽  
Claudia Rivera ◽  
Helena Korpelainen ◽  
Aldo Rojas ◽  
Paula Elomaa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Theobroma Cacao ◽  
Phytophthora Palmivora ◽  
Genetic Composition ◽  
Breeding Programmes ◽  
Black Pod ◽  
Black Pod Disease ◽  
Parental Lines ◽  
Resistant Genotypes ◽  
Theobroma Cacao L

A total of 60 farmers' cacao accessions (Theobroma cacao L.) from Nicaragua were investigated using microsatellite markers to reveal their genetic composition and to identify potentially resistant genotypes against the black pod disease caused by Phytophthora palmivora. These accessions were compared with 21 breeders' accessions maintained locally, two Criollo accessions from Costa Rica and two accessions from Ecuador. The analyses showed a low level of differentiation among groups of farmers' accessions (FST = 0.06) and that six Nicaraguan accessions were genetically closely related to the two Criollo accessions used as a reference. In addition, seven distinct genotypes were found to have allelic composition that may indicate linkage to resistance alleles, thus being potential parental lines in future breeding programmes.

scholarly journals Intelligent Characterization of Lentil Genetic Resources: Evolutionary History, Genetic Diversity of Germplasm, and the Need for Well‐Represented Collections

2021 ◽  
Vol 1 (5) ◽  
Author(s):  
Azalea Guerra‐García ◽  
Tania Gioia ◽  
Eric Wettberg ◽  
Giuseppina Logozzo ◽  
Roberto Papa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Evolutionary History

scholarly journals Spatial pattern and genetic diversity estimates are linked in stochastic models of population differentiation

2000 ◽  
Vol 23 (3) ◽  
pp. 541-544 ◽  
Author(s):  
José Alexandre Felizola Diniz-Filho ◽  
Mariana Pires de Campos Telles
Keyword(s):  
Genetic Diversity ◽  
Spatial Pattern ◽  
Stochastic Models ◽  
Population Differentiation ◽  
Real Data ◽  
Population Heterogeneity ◽  
Data Set ◽  
Mantel’S Test ◽  
The Relationship ◽  
Diversity Estimates

In the present study, we used both simulations and real data set analyses to show that, under stochastic processes of population differentiation, the concepts of spatial heterogeneity and spatial pattern overlap. In these processes, the proportion of variation among and within a population (measured by G ST and 1 - G ST, respectively) is correlated with the slope and intercept of a Mantel's test relating genetic and geographic distances. Beyond the conceptual interest, the inspection of the relationship between population heterogeneity and spatial pattern can be used to test departures from stochasticity in the study of population differentiation.

scholarly journals Conservation and directed utilization of forest genetic resources

2007 ◽  
pp. 7-21 ◽  
Author(s):  
Mirjana Sijacic-Nikolic ◽  
Jelena Milovanovic
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Genetic Resource ◽  
Environmental Changes ◽  
Future Generations ◽  
Forest Trees ◽  
The Earth ◽  
Forest Genetic ◽  
Forest Genetic Resources ◽  
Defensive Mechanism

Forest genetic resources represent the genetic diversity contained in the thousands of species of forest trees on the earth. their conservation is a set of activities and strategies, which are performed in the aim of ensuring the continued existence, evolution and availability of these resources for the present and future generations. the aim of genetic resource management is the enhancement of conditions for the continual evolution of the species which is the defensive mechanism of the organisms in the struggle with environmental changes.

scholarly journals Genetic flow among olive populations within the Mediterranean basin

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5260 ◽  
Author(s):  
Valentina di Rienzo ◽  
Sara Sion ◽  
Francesca Taranto ◽  
Nunzio D’Agostino ◽  
Cinzia Montemurro ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Olive Tree ◽  
Gene Pools ◽  
The North ◽  
The Mediterranean ◽  
And Migration ◽  
The Mediterranean Basin

Background The olive tree is a typical crop of the Mediterranean basin where it shows a wide diversity, accounting for more than 2,600 cultivars. The ability to discriminate olive cultivars and determine their genetic variability is pivotal for an optimal exploitation of olive genetic resources. Methods We investigated the genetic diversity within 128 olive accessions belonging to four countries in the Mediterranean Basin (Italy, Algeria, Syria, and Malta), with the purpose of better understanding the origin and spread of the olive genotypes across Mediterranean Basin countries. Eleven highly polymorphic simple sequence repeat (SSR) markers were used and proved to be very informative, producing a total of 179 alleles. Results Cluster analysis distinguished three main groups according to their geographical origin, with the current sample of Maltese accessions included in the Italian group. Phylogenetic analysis further differentiated Italian and Maltese olive accessions, clarifying the intermediate position of Maltese accessions along the x/y-axes of principal coordinate analysis (PCoA). Model-based and neighbor clustering, PCoA, and migration analysis suggested the existence of two different gene pools (Algerian and Syrian) and that the genetic exchange occurred between the Syrian, Italian and Maltese populations. Discussion The close relationship between Syrian and Italian and Maltese olives was consistent with the historical domestication and migration of olive tree from the North Levant to eastern Mediterranean basin. This study lays the foundations for a better understanding of olive genetic diversity in the Mediterranean basin and represents a step toward an optimal conservation and exploitation of olive genetic resources.

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