Microgeographical Patterns of Allozyme Variation in Casuarina cunninghamiana Miq Within and Between the Murrumbidgee and Coastal Drainage Systems

1989 ◽  
Vol 37 (2) ◽  
pp. 181 ◽  
Author(s):  
NJ Moore ◽  
GF Moran
Keyword(s):  
Genetic Diversity ◽  
Large Population ◽  
Drainage System ◽  
Allozyme Variation ◽  
Distance Measures ◽  
Drainage Systems ◽  
Casuarina Cunninghamiana ◽  
Total Genetic Diversity ◽  
Geographic Clustering

Within the Murrumbidgee drainage system, 100 seedlings from each of 14 populations of Casuarina cunninghamiana were assayed for their allozyme genotypes at 14 loci. The levels of genetic variation were fairly similar in all populations. There was no geographic clustering of populations based on genetic distance measures. Only 3.8% of the total genetic diversity could be apportioned among populations within the drainage system. In six additional populations, branchlets from 50 trees per population were assayed for their allozyme genotypes at 27 loci. Three populations were from the Murrumbidgee drainage system and each of the others from a different coastal drainage. The mean expected heterozygosities for coastal and inland zones were 0.139 and 0.093 respectively. Of the total genetic diversity 10.7% could be apportioned among the four drainages. The results of this study suggest that for in situ conservtion of C. cunninghamiana within a region, more emphasis should be placed on conserving one large population from each major drainage system rather than a number of populations within one or two drainage systems.

A Cline in Genetic Diversity in River She-Oak Casuarina cunninghamiana

1989 ◽  
Vol 37 (2) ◽  
pp. 169 ◽  
Author(s):  
GF Moran ◽  
JC Bell ◽  
JW Turnbull
Keyword(s):  
Genetic Diversity ◽  
Significant Positive Correlation ◽  
Population Level ◽  
Geographic Range ◽  
Northern Territory ◽  
Height Growth ◽  
Western Population ◽  
Casuarina Cunninghamiana ◽  
Total Genetic Diversity ◽  
Allozyme Loci

Twenty populations of Casuarina cunninghamiana Miq. covering its large geographic range were used in a study of genetic diversity. Genetic variation was measured by analysing 19 allozyme loci using 50 seedlings from each of the populations. The overall genetic diversity (HT = 0.287) in C. cunninghamiana is high compared to many other plant species. A significant fraction (26.4%) of the total genetic diversity could be apportioned among populations. This genetic differentiation between populations was not random. Populations in the eastern part of the range had high correlation (r = 0.91) of genetic diversity with latitude and this involved changes in allelic frequencies at several loci. At the population level, there was a significant positive correlation between genetic diversity and 1 year height growth. The western population from King River in the Northern Territory was very distinct genetically from all the other populations and this supported previous suggestions that the northwest part of the range is occupied by a different race of the species.

The genetic structure and the conservation of the five natural populations of Pinusradiata

1988 ◽  
Vol 18 (5) ◽  
pp. 506-514 ◽  
Author(s):  
G. F. Moran ◽  
J. C. Bell ◽  
K.G. Eldridge
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Conservation Strategies ◽  
Mainland Population ◽  
Island Populations ◽  
Expected Heterozygosity ◽  
Environmental Criteria ◽  
Total Genetic Diversity ◽  
Allozyme Loci

Pinusradiata is restricted to three mainland coastal populations in California and two island populations off Baja California, Mexico. In this study each population was divided into two geographic stands based on natural disjunctions within populations. In addition to the division mentioned above, each mainland population was also divided into a number of ecological stands based on ecological and environmental criteria. Genetic variation was measured by analysing 31 allozyme loci electrophoretically using germinated seed from 272 families across all stands and populations. Moderate levels of allozyme variation were found as shown by population averages for mean number of alleles per locus (1.79), percent polymorphic loci (46.4%, 0.99 criterion), and expected heterozygosity (0.098). In fact, the overall genetic diversity in P. radiata (HT = 0.117) is low compared with that of other conifers. In comparison with populations, the levels of allozyme variation in both ecological and geographic stands were slightly lower (means across ecological stands: A = 1.56, P = 39.3%, and He = 0.095). Of the total genetic diversity in P. radiata, 16.2% could be apportioned between populations, a high proportion for a conifer. In contrast, only 2.0 and 1.3% of the genetic diversity on average within mainland populations was between ecological and geographic stands, respectively. These results indicate a low level of genetic differentiation within populations, at least based on the ecological or geographic criteria used in this study. The implications and usefulness of these findings for the development of insitu conservation strategies are discussed.

Genetic diversity of Cistus albidus in south-east Spain does not relate to mesoclimate

2006 ◽  
Vol 33 (3) ◽  
pp. 247 ◽  
Author(s):  
Olga M. Grant ◽  
Tom McNeilly ◽  
Lynton D. Incoll
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Morphological Data ◽  
Population Divergence ◽  
Summer Drought ◽  
Growth Responses ◽  
Total Genetic Diversity ◽  
Cistus Albidus ◽  
Isozyme Loci

Patterns of variation at selected isozyme loci were examined in populations of Cistus albidus L. in south-east Spain, from areas differing in precipitation and temperature, to determine whether population divergence has occurred. Total genetic diversity was high, with a high percentage of the variation being found between populations. Genetic variation between populations did not relate to climate. Populations exposed to severe summer drought did not show lower genetic diversity than populations from more benign climates. Little genetic variation was found between populations that showed variation in ecophysiological and growth responses in situ and under controlled conditions. Cluster analyses showed different patterns of between-population distances with respect to genetic, physiological and morphological data, and none of these patterns corresponded to that for between-site environmental variation.

Allozyme Variation and Population Substructuring in the Caucasian Ground Lizards Lacerta derjugini and Lacerta praticola

2011 ◽  
Vol 4 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Ross D. MacCulloch ◽  
Ilya S. Darevsky ◽  
Robert W. Murphy ◽  
Jinzhong Fu
Keyword(s):  
Genetic Diversity ◽  
Allozyme Variation ◽  
Close Proximity ◽  
Geographic Separation ◽  
Population Substructuring ◽  
Allozyme Loci ◽  
Two Populations

Genetic diversity at 35 allozyme loci was surveyed in Lacerta derjugini (3 populations) and L. praticola (2 populations). Indices of variability were consistent with those found in other Caucasian Lacerta. There was little genetic substructuring between two populations of L. praticola despite considerable geographic separation. Conversely, populations of L. derjugini in close proximity to one another exhibited considerable substructuring.

Allozyme variation and an estimate of the inbreeding coefficient in the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae)

1995 ◽  
Vol 85 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Philippe Borsa ◽  
D. Pierre Gingerich
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Population Genetic ◽  
New Caledonia ◽  
Allozyme Variation ◽  
Inbreeding Coefficient ◽  
Hypothenemus Hampei ◽  
Coffee Berry ◽  
Biological Features ◽  
High Degree

AbstractSeven presumed Mendelian enzyme loci (Est-2, Est-3, Gpi, Idh-l, Idh-2, Mdh-2 and Mpi) were characterized and tested for polymorphism in coffee berry borers, Hypothenemus hampei (Ferrari), sampled in Côte d′Ivoire, Mexico and New Caledonia. The average genetic diversity was H = 0.080. Two loci, Mdh-2 and Mpi were polymorphic, and thus usable as genetic markers. The population structure of H. hampei was analysed using Weir & Cockerham's estimators of Wright's F-statistics. A high degree of inbreeding (f = 0.298) characterized the elementary geographic sampling unit, the coffee field. The estimate of gene flow between fields within a country was Nm = 10.6 and that between countries was Nm = 2. The population genetic structure in H. hampei could be related to its known population biological features and history.

scholarly journals Inclusion of Hydraulic Controls in Rehabilitation Models of Drainage Networks to Control Floods

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 514
Author(s):  
Leonardo Bayas-Jiménez ◽  
F. Javier Martínez-Solano ◽  
Pedro L. Iglesias-Rey ◽  
Daniel Mora-Melia ◽  
Vicente S. Fuertes-Miquel
Keyword(s):  
Genetic Algorithm ◽  
Drainage System ◽  
Optimal Solution ◽  
Hydraulic Control ◽  
Drainage Systems ◽  
Storm Water Management Model ◽  
Drainage Networks ◽  
Extreme Rain ◽  
Rain Events ◽  
The Cost

A problem for drainage systems managers is the increase in extreme rain events that are increasing in various parts of the world. Their occurrence produces hydraulic overload in the drainage system and consequently floods. Adapting the existing infrastructure to be able to receive extreme rains without generating consequences for cities’ inhabitants has become a necessity. This research shows a new way to improve drainage systems with minimal investment costs, using for this purpose a novel methodology that considers the inclusion of hydraulic control elements in the network, the installation of storm tanks and the replacement of pipes. The presented methodology uses the Storm Water Management Model for the hydraulic analysis of the network and a modified Genetic Algorithm to optimize the network. In this algorithm, called the Pseudo-Genetic Algorithm, the coding of the chromosomes is integral and has been used in previous studies of hydraulic optimization. This work evaluates the cost of the required infrastructure and the damage caused by floods to find the optimal solution. The main conclusion of this study is that the inclusion of hydraulic controls can reduce the cost of network rehabilitation and decrease flood levels.

scholarly journals The Relevance of Grated Inlets within Surface Drainage Systems in the Field of Urban Flood Resilience. A Review of Several Experimental and Numerical Simulation Approaches

2021 ◽  
Vol 13 (13) ◽  
pp. 7189
Author(s):  
Beniamino Russo ◽  
Manuel Gómez Valentín ◽  
Jackson Tellez-Álvarez
Keyword(s):  
Overland Flow ◽  
Drainage System ◽  
Critical Conditions ◽  
Hydraulic Efficiency ◽  
Storm Events ◽  
Urban Resilience ◽  
Urban Flood ◽  
Drainage Systems ◽  
Surface Drainage ◽  
Intense Storm

Urban drainage networks should be designed and operated preferably under open channel flow conditions without flux return, backwater, or overflows. In the case of extreme storm events, urban pluvial flooding is generated by the excess of surface runoff that could not be conveyed by pressurized sewer pipes, due to its limited capacity or, many times, due to the poor efficiency of surface drainage systems to collect uncontrolled overland flow. Generally, the hydraulic design of sewer systems is addressed more for underground networks, neglecting the surface drainage system, although inadequate inlet spacings and locations can cause dangerous flooding with relevant socio-economic impacts and the interruption of critical services and urban activities. Several experimental and numerical studies carried out at the Technical University of Catalonia (UPC) and other research institutions demonstrated that the hydraulic efficiency of inlets can be very low under critical conditions (e.g., high circulating overland flow on steep areas). In these cases, the hydraulic efficiency of conventional grated inlets and continuous transverse elements can be around 10–20%. Their hydraulic capacity, expressed in terms of discharge coefficients, shows the same criticism with values quite far from those that are usually used in several project practice phases. The grate clogging phenomenon and more intense storm events produced by climate change could further reduce the inlets’ performance. In this context, in order to improve the flood urban resilience of our cities, the relevance of the hydraulic behavior of surface drainage systems is clear.

Genetic diversity of the extremely rare Habenaria dentata and the rare Habenaria linearifolia (Orchidaceae) in South Korea: implications for population history and conservation

2018 ◽  
Vol 151 (1) ◽  
pp. 48-60
Author(s):  
Mi Yoon Chung ◽  
Hoa Thi Quynh Le ◽  
Sungwon Son ◽  
Huai Zhen Tian ◽  
Myong Gi Chung
Keyword(s):  
Genetic Diversity ◽  
Southern China ◽  
Geographic Location ◽  
Population History ◽  
Population Variation ◽  
Conservation Strategies ◽  
Ancestral Population ◽  
Allozyme Diversity ◽  
Glacial Origin

Background and aims – Since historical events often leave an indelible mark on levels of genetic diversity of plant populations, one may indirectly infer their evolutionary history with the help of current patterns of genetic diversity. The terrestrial orchid Habenaria dentata, an element of warm-temperate/subtropical vegetation, reaches its northernmost limits in the Korean Peninsula, and thus it is extremely rare there. As H. dentata was absent from the Peninsula during the Last Glacial Maximum (LGM), it is likely to be of post-glacial origin having arrived from either a single refugium or multiple refugia. However, its rare, temperate/boreal congener H. linearifolia might have persisted in situ in either macrorefugia or microrefugia on the Peninsula during the LGM.Methods – To test which hypothesis is most appropriate for each species, we investigated levels of allozyme-based (17 loci) genetic diversity and population genetic structure in the two only known populations of H. dentata and in 12 populations of H. linearifolia.Key results – No allozyme diversity was found in H. dentata (He = 0.000), whereas H. linearifolia exhibited low within-population variation (He = 0.060) and high among-population differentiation (FST = 0.237). We found little association between populations in relation to their geographic location; several populations presented individuals belonging to different clusters.Conclusions – Our results suggest that H. dentata likely originated from a single ancestral population (perhaps from southern Japan or southern China) through post-glacial dispersal, whereas H. linearifolia probably survived the LGM in situ in microrefugia situated at low to mid-elevated regions. We further suggest that separate conservation strategies for each species should be employed, given that the two taxa have different ecological and demographic traits and harbour different levels of genetic diversity.

scholarly journals Genetic diversity and evolution of hepatitis C virus – 15 years on

2004 ◽  
Vol 85 (11) ◽  
pp. 3173-3188 ◽  
Author(s):  
Peter Simmonds
Keyword(s):  
Genetic Diversity ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Human Liver ◽  
Large Population ◽  
Sequence Divergence ◽  
Selection Pressures ◽  
Host Interactions ◽  
Persistent Viruses ◽  
The Face

In the 15 years since the discovery of hepatitis C virus (HCV), much has been learned about its role as a major causative agent of human liver disease and its ability to persist in the face of host-cell defences and the immune system. This review describes what is known about the diversity of HCV, the current classification of HCV genotypes within the family Flaviviridae and how this genetic diversity contributes to its pathogenesis. On one hand, diversification of HCV has been constrained by its intimate adaptation to its host. Despite the >30 % nucleotide sequence divergence between genotypes, HCV variants nevertheless remain remarkably similar in their transmission dynamics, persistence and disease development. Nowhere is this more evident than in the evolutionary conservation of numerous evasion methods to counteract the cell's innate antiviral defence pathways; this series of highly complex virus–host interactions may represent key components in establishing its ‘ecological niche’ in the human liver. On the other hand, the mutability and large population size of HCV enables it to respond very rapidly to new selection pressures, manifested by immune-driven changes in T- and B-cell epitopes that are encountered on transmission between individuals with different antigen-recognition repertoires. If human immunodeficiency virus type 1 is a precedent, future therapies that target virus protease or polymerase enzymes may also select very rapidly for antiviral-resistant mutants. These contrasting aspects of conservatism and adaptability provide a fascinating paradigm in which to explore the complex selection pressures that underlie the evolution of HCV and other persistent viruses.

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