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 Genetic Diversity and Population Structure of Bermudagrass [Cynodon dactylon (L.) Pers.] along Latitudinal Gradients and the Relationship with Polyploidy Level

Diversity ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 135 ◽  
Author(s):  
Jingxue Zhang ◽  
Miaoli Wang ◽  
Zhipeng Guo ◽  
Yongzhuo Guan ◽  
Jianyu Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Population Genetic ◽  
Cynodon Dactylon ◽  
Latitudinal Gradients ◽  
Wind Pollination ◽  
Ploidy Levels ◽  
Sexual And Asexual Reproduction ◽  
Genetic Pattern

Understanding the population genetic pattern and process of gene flow requires a detailed knowledge of how landscape characteristics structure populations. Although Cynodon dactylon (L.) Pers. (common bermudagrass) is widely distributed in the world, information on its genetic pattern and population structure along latitudinal gradients is limited. We tried to estimate the genetic diversity and genetic structure of C. dactylon along a latitudinal gradient across China. Genetic diversity among different ploidy levels was also compared in the study. The material used consisted of 296 C. dactylon individuals sampled from 16 geographic sites from 22°35′ N to 36°18′ N. Genetic diversity was estimated using 153 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. Higher within-population genetic diversity appeared at low-latitude, as well as having positive correlation with temperature and precipitation. The genetic diversity increased with the ploidy level of C. dactylon, suggesting polyploidy creates higher genetic diversity. No isolation by distance and notable admixture structure existed among populations along latitudes. Both seed dispersal (or vegetative organs) and extrinsic pollen played important roles for gene flow in shaping the spatial admixture population structure of C. dactylon along latitudes. In addition, populations were separated into three clusters according to ploidy levels. C. dactylon has many such biological characters of perennial growth, wind-pollination, polyploidy, low genetic differentiation among populations, sexual and asexual reproduction leading to higher genetic diversity, which gives it strong adaptability with its genetic patterns being very complex across all the sampled latitudes. The findings of this study are related to landscape population evolution, polyploidy speciation, preservation, and use of bermudagrass breeding.

Patterns of allozyme variation within and among Douglas-fir breeding zones in southwest Oregon

1987 ◽  
Vol 17 (5) ◽  
pp. 402-407 ◽  
Author(s):  
S. A. Merkle ◽  
W. T. Adams
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Frequency ◽  
Quantitative Traits ◽  
Allozyme Variation ◽  
Douglas Fir ◽  
Expected Heterozygosity ◽  
Breeding Zone ◽  
Southwest Oregon ◽  
Environmental Distance

Gametophytes from wind-pollinated seeds of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) parent trees (mean 56) in each of 22 breeding zones in southwest Oregon were analyzed electrophoretically for gene frequency patterns at 27 loci. Allozyme variability levels were high, as shown by breeding-zone averages for the percentage of polymorphic loci (71.7%, 0.99 criterion), mean number of alleles per locus (2.46), and expected heterozygosity (0.178). Differences among zones in allele frequency were significant (p < 0.05) for only 2 of the 27 loci surveyed, and analysis of hierarchical population structure showed that less than 1% of genetic diversity was attributable to differences among breeding zones. Genetic distance between zones was small [Formula: see text] and, in general, bore no relation to geographical or environmental distance. The limited allozyme differentiation among zones contrasts strikingly with the environment-related variation in seedling quantitative traits previously reported for southwest Oregon Douglas-fir. Allozymes do not appear to be useful for mapping patterns of adaptive variation or for certifying Douglas-fir seed in this region.

scholarly journals Population structure of Opisthorchis felineus (Trematoda) and its second intermediate hosts — cyprinid fishes in the Ob-Irtysh focus of opisthorchiasis, based on allozyme data

2014 ◽  
Vol 51 (4) ◽  
pp. 309-317 ◽  
Author(s):  
O. Zhigileva ◽  
V. Ozhireľev ◽  
T. Stepanova ◽  
T. Moiseenko
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Allozyme Variation ◽  
Intermediate Hosts ◽  
Opisthorchis Felineus ◽  
Cyprinid Fishes ◽  
Low Levels

AbstractGenetic variability of West Siberian populations of Opisthorchis felineus and two species of cyprinid fish, its second intermediate hosts, was studied by isozyme analysis. Low levels of allozyme variation and genetic differentiation in O. felineus from the Ob-Irtysh focus of opisthorchiasis were detected. The proportion of polymorphic loci was 21.1 %, the average observed heterozygosity (Hobs) was 0.008, and expected heterozygosity (Hexp) was 0.052. For most loci in O. felineus deficit of heterozygotes (FIS = 0.7424) was observed. A comparison of population genetic structure of fish and parasites showed they were not congruent. Estimates of genetic differentiation of the parasite were smaller than for the fish — its intermediate host. Migration and population structure of the second intermediate hosts do not play an important role in formation of the population-genetic structure of O. felineus in the Ob-Irtysh focus of opisthorchiasis.

A molecular diagnostic for endosulfan insecticide resistance in the coffee berry borer Hypothenemus hampei (Coleoptera: Scolytidae)

1994 ◽  
Vol 84 (1) ◽  
pp. 11-15 ◽  
Author(s):  
R.H. ffrench-Constant ◽  
J.C. Steichen ◽  
L.O. Brun
Keyword(s):  
New Caledonia ◽  
Chloride Ion ◽  
Amino Acid Replacement ◽  
Single Amino Acid ◽  
Molecular Diagnostic ◽  
Hypothenemus Hampei ◽  
Coffee Berry ◽  
Degenerate Primers ◽  
Coffee Berry Borer ◽  
Population Outbreaks

AbstractThe coffee berry borer Hypothenemus hampei (Ferrari) has recently evolved high levels of resistance to endosulfan and other cyclodiene-type insecticides in New Caledonia. During population outbreaks this has contributed to levels of infestation of coffee berries reaching up to 90%. Using degenerate primers in the polymerase chain reaction (PCR) we have amplified a section of the cyclodiene resistance gene Rdl from H. hampei. This gene codes for a γ-aminobutyric acid (GABA) gated chloride ion channel. Here we report that resistant strains of H. hampei carry exactly the same single amino acid replacement (alanine to serine) as that found in resistant Drosophila melanogaster (Meigen) (Diptera: Drosophilidae). A molecular diagnostic based upon PCR-mediated amplification of specific alleles (PASA) is described. This technique is capable of detecting resistance or susceptibility in adults, larvae or eggs but not in susceptible females carrying resistant sperm. Its potential use in field monitoring is discussed.

scholarly journals Non-linear genetic diversity and notable population differentiation caused by low gene flow of bermudagrass [Cynodon dactylon (L.) Pers.] along longitude gradients

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11953
Author(s):  
Jing-Xue Zhang ◽  
Miaoli Wang ◽  
Jibiao Fan ◽  
Zhi-Peng Guo ◽  
Yongzhuo Guan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Genetic Distance ◽  
Ploidy Level ◽  
Population Genetic ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Ploidy Levels ◽  
Population Genetic Diversity

Background Environmental variation related to ecological habitat is the main driver of plant adaptive divergence. Longitude plays an important role in the formation of plant population structure, indicating that environmental differentiation can significantly shape population structure. Methods Genetic diversity and population genetic structure were estimated using 105 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. A total of 249 C. dactylon (L.) Pers. (common bermudagrass) individuals were sampled from 13 geographic sites along the longitude (105°57′34″–119°27′06″E). Results There was no obvious linear trend of intra-population genetic diversity along longitude and the intra-population genetic diversity was not related to climate in this study. Low gene flow (Nm = 0.7701) meant a rich genetic differentiation among populations of C. dactylon along longitude gradients. Significantly positive Mantel correlation (r = 0.438, P = 0.001) was found between genetic distance and geographical interval while no significant partial Mantel correlation after controlling the effect of mean annual precipitation, which indicated geographic distance correlated with mean annual precipitation affect genetic distance. The genetic diversity of C. dactylon with higher ploidy level was higher than that with lower ploidy level and groups of individuals with higher ploidy level were separated further away by genetic distance from the lower ploidy levels. Understanding the different genetic bases of local adaptation comparatively between latitude and longitude is one of the core findings in the adaptive evolution of plants.

scholarly journals Population structure and geographic segregation of Cryptosporidium parvum IId subtypes in cattle in China

2020 ◽  
Author(s):  
Zhenjie Zhang ◽  
Suhui Hu ◽  
Wentao Zhao ◽  
Yaqiong Guo ◽  
Na Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Sequence Analysis ◽  
Cryptosporidium Parvum ◽  
Population Genetic ◽  
Principal Component ◽  
Farm Animals ◽  
Industrialized Countries ◽  
Genetic Characteristics ◽  
Distance Analysis

Abstract Background: Cryptosporidium parvum is a zoonotic pathogen worldwide. Extensive genetic diversity and complex population structures exist in C. parvum in different geographic regions and hosts. Unlike the IIa subtype family, which is responsible for most zoonotic C. parvum infections in industrialized countries, IId is identified as the dominant subtype family in farm animals, rodents, and humans in China. Thus far, the population genetic characteristics of IId subtypes in calves in China are not clear. Methods: In the present study, 46 C. parvum isolates from dairy and beef cattle in six provinces and regions, China were characterized using sequence analysis of eight genetic loci, including msc6-7 , rpgr , msc6-5 , dz-hrgp , chom3t , hsp70 , mucin1 , and gp60 . They belonged to three IId subtypes in the gp60 gene, including IIdA20G1 (n = 17), IIdA19G1 (n = 24) and IIdA15G1 (n = 5). The data generated were analyzed for population genetic structures of C. parvum using DnaSP and LIAN, and subpopulation structures using STRUCTURE, RAxML, Arlequin, GENALEX and Network. Results: Seventeen multilocus genotypes were identified. The results of linkage disequilibrium analysis indicated the presence of an epidemic genetic structure in the C. parvum IId population. When isolates of various geographical areas were treated as individual subpopulations, maximum likelihood inference of phylogeny, pairwise genetic distance analysis, sub-structure analysis, principal component analysis and network analysis all provided evidence for geographic segregation of subpopulations in Heilongjiang, Hebei, and Xinjiang. In contrast, isolates from Guangdong, Shanghai, and Jiangsu were genetically like each other. Conclusions: Data from the multilocus analysis have revealed a much higher genetic diversity of C. parvum than gp60 sequence analysis. Despite an epidemic population structure, there is apparent geographic segregation in C. parvum subpopulations within China.

The Breeding System, Genetic Diversity and Pollen Sterility in Eucalyptus pulverulenta, a Rare Species With Small Disjunct Populations

1990 ◽  
Vol 38 (6) ◽  
pp. 559 ◽  
Author(s):  
GB Peters ◽  
JS Lonie ◽  
GF Moran
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Rare Species ◽  
Population Genetic ◽  
Pollen Sterility ◽  
Species Range ◽  
Disjunct Distribution ◽  
Eastern Australia ◽  
The Mean ◽  
Allozyme Loci

There are eight known populations of E. pulverulenta, which has a disjunct distribution in south-eastern Australia. Levels of genetic variation were studied in four populations of about 5000 plants in all. Of a total of 16 allozyme loci examined eight were polymorphic, but the level of polymorphism was generally low. Within populations there was a mean 1.42 alleles per locus. Both the total species and mean population genetic diversities were low for a tree species (0.10 and 0.07 respectively), while the between-population genetic diversity was high at 30%. These data are consistent with the effects expected of genetic drift. Population structure may thus have been critical in determining levels of genetic diversity throughout the species' range. Analysis of half-sib arrays in three populations showed that the mean outcrossing rate (t) was 70%, comparable to values from other Eucalyptus species. The mean level of inbreeding (Wright's F) was 0.19, although both F and t varied considerably between populations. Significant levels of pollen sterility have been reported in this species, and data presented here show that this trait extends through much of the species' range. Overall, these data suggest that neither its disjunct population structure nor its tendency to male sterility caused the species' detectable level of outcrossing to differ markedly from levels reported in other eucalypt species. However, it remains possible that pollen sterility may have had some effect in at least one population. Strategies for conservation of this rare species are also considered.

Allozyme variation and population structure of Carex humilis var. nana (Cyperaceae) in Korea

2001 ◽  
Vol 79 (4) ◽  
pp. 457-463 ◽  
Author(s):  
Man Kyu Huh
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
North American ◽  
Population Level ◽  
Allozyme Variation ◽  
Population Divergence ◽  
Geographic Ranges ◽  
The Mean ◽  
Allozyme Loci

Genetic diversity and population structure of 22 Carex humilis var. nana Ohwi (Cyperaceae) populations in Korea were determined using genetic variation at 23 allozyme loci. This is a long-lived herbaceous species with a widespread distribution in eastern Asia. The 12 enzymes revealed 23 putative loci, of which 11 were polymorphic (47.8%). Genetic diversity at the varietal level and at the population level was 0.131 and 0.118, respectively. Total genetic diversity (HT = 0.274) and within population genetic diversity (HS = 0.256) were high, whereas the extent of the population divergence was relatively low (GST = 0.068). An indirect estimate of the number of migrants per generation (Nm = 3.42) indicated that gene flow was high among Korean populations. Wide geographic ranges, perennial herbaceous nature, and the persistence of multiple generations are associated with the high level of genetic variation. A distinct difference between Asian and North American Carex is shown in the proportion of genetic variation (GST) (p < 0.001). The mean GST of Asian Carex was estimated as 0.056; thus, only 5.6% of genetic variability was distributed among populations, whereas the mean GST of North American Carex was estimated as 19.5% (3.5 times higher). It is probable that the geographical distance between population pairs and presence or absence of glacial history may play roles in the substantial difference between both groups.Key words: Carex humilis var. nana, genetic diversity, population structure.

Inbreeding in the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae) estimated from endosulfan resistance phenotype frequencies

1996 ◽  
Vol 86 (6) ◽  
pp. 667-674 ◽  
Author(s):  
D. Pierre Gingerich ◽  
Philippe Borsa ◽  
D. Maxwell Suckling ◽  
Luc-Olivier Brun
Keyword(s):  
New Caledonia ◽  
High Dose ◽  
Hypothenemus Hampei ◽  
Coffee Berry ◽  
Coffee Berry Borer ◽  
Resistance Evolution ◽  
Genotype Frequencies ◽  
The Difference ◽  
High Level ◽  
Homozygous Resistant

AbstractAn estimate of the inbreeding coefficient, FIS, of the coffee berry borer, Hypothenemus hampei Ferrari, was calculated from genotype frequencies of endosulfan resistance in beetles collected from berries in 41 different fields on the East Coast of New Caledonia. Two different estimates were obtained as a function of sampling date: FIS=0.491 ± 0.059 (s.e.) for samples collected in September, and FIS=0.215 ± 0.108 for samples collected in April. These values of FIS are very high in comparison to those of most insects, but surprisingly low given current understandings of H. hampei mating patterns. The difference between April and September FIS estimates is discussed in terms of insecticide regimes and seasonal variability of sib inbreeding levels. The high level of inbreeding in the coffee berry borer increases frequencies of homozygotes relative to heterozygotes. Inbreeding will accelerate resistance evolution whenever the fitness of homozygous resistant insects exceeds that of heterozygotes, and will undermine any high-dose strategy to control resistance evolution.

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