Genetic variability in Indian populations of banana corm weevil [Cosmopolites sordidus (Coleoptera: Curculionidae)] assessed by RAPDs and AFLPs

2017 ◽  
Vol 37 (03) ◽  
pp. 149-162 ◽  
Author(s):  
Sweta Kumari U. Yadav ◽  
Jyotsna Singh ◽  
B. Padmanaban ◽  
Lalitha Sunil Kumar
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Hot Spot ◽  
Random Amplified Polymorphic Dna ◽  
Geographic Distance ◽  
Mantel Test ◽  
Cosmopolites Sordidus ◽  
Restricted Gene Flow ◽  
Control And Management ◽  
Economic Pest

AbstractCosmopolites sordidus(Germar), commonly known as banana corm weevil, is an important economic pest in Asia that can cause severe yield loss depending upon the stage at which infestation occurs. In spite of its economic importance, little is known about the population structure of this pest in India. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) were used to characterize the population genetic structure ofC. sordiduscollected from five hot spot locations in India. Nineteen RAPD primers and five selective AFLP primer combinations generated 147 and 304 amplification products, respectively. UPGMA dendrograms generated with both marker systems failed to reveal populations clustered based on geographic distance, which was confirmed by the Mantel test, which did not show a strong correlation between genetic distance and geographic distance. Values of indices of genetic identity showed that the populations were closely related. Though the gene flow estimate (Nm) between the populations was 0.469, suggesting restricted gene flow, the populations are not genetically distinct. These observations suggest that the range expansion of this banana pest in India has taken place through transport of infested corms and plant material, resulting in genetically close populations that are geographically distinct. These results provide important information on the population structure of this pest in India, which will aid in designing suitable strategies for its control and management, especially with respect to insecticide resistance.

scholarly journals Isozyme and RAPD studies in Prosopis glandulosa and P. Velutina (Leguminosae, Mimosoideae)

2000 ◽  
Vol 23 (3) ◽  
pp. 639-648 ◽  
Author(s):  
Cecilia Bessega ◽  
Beatriz O. Saidman ◽  
Juan C. Vilardi
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Genetic Differentiation ◽  
Rapd Markers ◽  
Random Amplified Polymorphic Dna ◽  
Mantel Test ◽  
Prosopis Glandulosa ◽  
Geographical Distance ◽  
Taxonomic Studies

Allozyme and random amplified polymorphic DNA (RAPD) techniques have been compared for their usefulness for genetic and taxonomic studies in Prosopis glandulosa and P. velutina populations. Isozymes and RAPDs yielded similarly high estimates of genetic variability. Genetic structure and differentiation were analyzed through non-hierarchical Wright's F DT. For all populations considered, both markers produced low gene flow (Nm < 1) estimates. When only P. glandulosa populations were analyzed, isozyme data yielded higher gene flow estimates (Nm > 1), in agreement with that expected for conspecific populations. However, in RAPD data the expected reduction in F DT and the increase in Nm were not observed. Correlation between F DT and geographical distance matrices (Mantel test) for all populations was significant (P = 0.02) when based on isozymes, but not so (P = 0.33) when based on RAPDs. No significant associations among genetic and geographical or climatic variables were observed. Two isoenzyme systems (GOT and PRX) enabled us to distinguish between P. glandulosa and P. velutina, but no diagnostic band for recognition of populations or species studied here were detected by RAPD. However, RAPD markers showed higher values for genetic differentiation among conspecific populations of P. glandulosa and a lower coefficient of variation than those obtained from isozymes.

scholarly journals Progressive colonization and restricted gene flow shape island-dependent population structure in Galápagos marine iguanas (Amblyrhynchus cristatus)

2009 ◽  
Vol 9 (1) ◽  
pp. 297 ◽  
Author(s):  
Sebastian Steinfartz ◽  
Scott Glaberman ◽  
Deborah Lanterbecq ◽  
Michael A Russello ◽  
Sabrina Rosa ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Restricted Gene Flow ◽  
Amblyrhynchus Cristatus ◽  
Marine Iguanas

scholarly journals Genetic population structure of Gyrodactylus thymalli (Monogenea) in a large Norwegian river system

Parasitology ◽  
2015 ◽  
Vol 142 (14) ◽  
pp. 1693-1702 ◽  
Author(s):  
RUBEN ALEXANDER PETTERSEN ◽  
TOR ATLE MO ◽  
HAAKON HANSEN ◽  
LEIF ASBJØRN VØLLESTAD
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Gene Flow ◽  
Haplotype Diversity ◽  
River System ◽  
Genetic Population Structure ◽  
Restricted Gene Flow ◽  
Upstream Migration ◽  
Genetic Population ◽  
Long Time

SUMMARYThe extent of geographic genetic variation is the result of several processes such as mutation, gene flow, selection and drift. Processes that structure the populations of parasite species are often directly linked to the processes that influence the host. Here, we investigate the genetic population structure of the ectoparasite Gyrodactylus thymalli Žitňan, 1960 (Monogenea) collected from grayling (Thymallus thymallus L.) throughout the river Glomma, the largest watercourse in Norway. Parts of the mitochondrial dehydrogenase subunit 5 (NADH 5) and cytochrome oxidase I (COI) genes from 309 G. thymalli were analysed to study the genetic variation and investigated the geographical distribution of parasite haplotypes. Three main clusters of haplotypes dominated the three distinct geographic parts of the river system; one cluster dominated in the western main stem of the river, one in the eastern and one in the lower part. There was a positive correlation between pairwise genetic distance and hydrographic distance. The results indicate restricted gene flow between sub-populations of G. thymalli, most likely due to barriers that limit upstream migration of infected grayling. More than 80% of the populations had private haplotypes, also indicating long-time isolation of sub-populations. According to a molecular clock calibration, much of the haplotype diversity of G. thymalli in the river Glomma has developed after the last glaciation.

scholarly journals Genetic Diversity and Population Structure of Chinese Corylus heterophylla and Corylus kweichowensis Using Simple Sequence Repeat Markers

2020 ◽  
Vol 145 (5) ◽  
pp. 289-298
Author(s):  
Tiantian Zhao ◽  
Wenxu Ma ◽  
Qinghua Ma ◽  
Zhen Yang ◽  
Lisong Liang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Relationships ◽  
In Situ Conservation ◽  
Geographic Distance ◽  
Natural Populations ◽  
Distinct Species ◽  
Mantel Test ◽  
Conservation Of Genetic Resources ◽  
Genetic Clusters

Corylus heterophylla and Corylus kweichowensis are economically and ecologically important nut-producing woody shrubs that are distributed across northern and southern regions of China. However, few studies have examined the genetic diversity and genetic relationships between C. heterophylla and C. kweichowensis, and their taxonomic relationships have been questioned. In this study, 796 individuals collected from 34 natural populations (21 C. heterophylla and 13 C. kweichowensis populations) were investigated to assess the genetic diversity and population structure using 11 microsatellite loci. Analysis of molecular variance revealed that genetic differentiation of C. heterophylla and C. kweichowensis within populations accounted for 93.57% and 88.91% of total variation, respectively. The C. heterophylla and C. kweichowensis populations as a whole group were analyzed by multiple programs, which showed that the 34 populations were divided into two genetic clusters. One cluster included 21 C. heterophylla populations, and the second cluster contained 13 C. kweichowensis populations. We conclude from these results that C. heterophylla and C. kweichowensis are distinct species. The Mantel test showed that the genetic distance was significantly correlated with the geographic distance (r = 0.580, P < 0.001). The populations of C. heterophylla [e.g., populations WC (Weichang), MS (Mishan), and WA (Wu’an)] and C. kweichowensis [e.g., populations YX (Yuexi), ZP (Zhenping), LA (Lin’an), and TB (Taibai)] with high allelic richness are considered suitable for in situ conservation. Our study provides valuable information for breeding and conservation of genetic resources of C. heterophylla, C. kweichowensis, and related species.

The population structure of Armillaria ostoyae in the southern interior of British Columbia

2001 ◽  
Vol 79 (5) ◽  
pp. 612-620 ◽  
Author(s):  
Jeremy R Dettman ◽  
Bart J van der Kamp
Keyword(s):  
British Columbia ◽  
Population Structure ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Random Mating ◽  
Geographic Distance ◽  
Symptom Expression ◽  
Armillaria Ostoyae ◽  
Term Maintenance

The population structure of Armillaria ostoyae (Romagn.) Herink was investigated at a study site in the interior cedar–hemlock zone of the southern interior of British Columbia. Eight 500-m long, randomly placed transects located at least 500 m apart were systematically sampled and individual genets were delineated using Random Amplified Polymorphic DNA (RAPD) analysis. Average genet intersect length was 79 m, and an estimated 88% of the area surveyed was occupied by genets <2 ha in size. The spatial distribution of genets in relation to one another was quite complex, with isolates of the same genet often non-contiguous along the transect. The location of genets could not be determined from aboveground symptom expression. Isolates collected from adjacent hosts within small groups of symptomatic hosts (infection foci) did not necessarily belong to the same genet, but single genets could occupy several infection foci. There was no relationship between geographic distance and genetic similarity of genets, suggesting random mating events for genet origin and long term maintenance of genetic identity.Key words: Armillaria, RAPD, population structure, genet, ramet, clone.

scholarly journals Molecular Characterization of Lates niloticus (Perciformes, Latidae) Populations from three Nigerian Waterbodies using Random Amplified Polymorphic DNA and Microsatellite Markers

2017 ◽  
Vol 51 (1) ◽  
pp. 31-36
Author(s):  
K. E. Ogbuebunu ◽  
M. O. Awodiran
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Microsatellite Markers ◽  
Random Amplified Polymorphic Dna ◽  
Population Level ◽  
Effective Number ◽  
Lates Niloticus ◽  
The Mean

Abstract Thirty Lates niloticus (Linnaeus, 1758) from three Nigerian waterbodies were genotyped on six RAPD primers and five microsatellites loci. RAPD revealed that effective number of alleles (AE) at population level per locus was within the range of 1.641 ± 0.066 to 1.645 ± 0.041 while the mean number of alleles (AN) across populations equals 2.000. Characterization on five microsatellites loci revealed genetic diversity within and among studied populations. Observed heterozygousity (HO) was within the range of 0.317 ± 0.335 to 0.523 ± 0.315 while expected heterozygousity (HE) was within the range of 0.414 ± 0.306 to 0.715 ± 0.097. Proportion of differentiation (FST) within populations was 0.236. Overall gene flow (Nm) among populations equals 0.806. This study established the successful use of RAPD and microsatellite as tools for studying population structure of fish species, especially L. niloticus. Thus, it can be concluded that L. niloticus in the three (3) sampled Nigerian waterbodies is undergoing evolution.

Population structure of the Patagonian toothfish around Heard, McDonald and Macquarie Islands

2002 ◽  
Vol 14 (4) ◽  
pp. 364-373 ◽  
Author(s):  
SHARON A. APPLEYARD ◽  
ROBERT D. WARD ◽  
RICHARD WILLIAMS
Keyword(s):  
Mitochondrial Dna ◽  
Population Structure ◽  
Gene Flow ◽  
Genetic Heterogeneity ◽  
Restricted Gene Flow ◽  
Effective Population ◽  
Significant Differentiation ◽  
Macquarie Island ◽  
Male Dispersal ◽  
Patagonian Toothfish

Two mitochondrial DNA regions and seven microsatellite loci were examined in Patagonian toothfish from three locations in the Southern Ocean (Macquarie Island, five collections; Heard and McDonald Islands, four collections; Shag Rocks/South Georgia area, one collection). Striking mtDNA heterogeneity was detected between the three fishing locations (FST=0.445, P<0.001), but spatial and temporal collections within the same location were not significantly different. No significant overall microsatellite differentiation between the three locations was apparent (FST=−0.009, P=0.785). However, some individual loci showed small but significant differentiation, which in each case was attributable to between rather than within-location differentiation. Greater differentiation of mtDNA can, in principle, be explained either by female philopatry and male dispersal, or by its greater sensitivity to changes in effective population size. The latter seems more likely as tagging indicates that toothfish is generally a sedentary species. The genetic heterogeneity between the three locations indicates restricted gene flow, with the fish at each location comprising independent units. Depletion in one location is therefore unlikely to be quickly replaced by immigration from another.

Population structure and phylogenetic relationships of Ceutorhynchus neglectus (Coleoptera: Curculionidae)

2005 ◽  
Vol 137 (6) ◽  
pp. 672-684 ◽  
Author(s):  
R. D. Laffin ◽  
L. M. Dosdall ◽  
F.A.H. Sperling
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
North America ◽  
Phylogenetic Relationships ◽  
Nuclear Dna ◽  
Isolation By Distance ◽  
Coi Gene ◽  
Restricted Gene Flow ◽  
Species Variation ◽  
Internal Transcribed Spacer Region

AbstractCeutorhynchus neglectus Blatchley is a weevil that is native to, and widely distributed in, North America. It has life-history characteristics similar to its alien invasive congener, Ceutorhynchus obstrictus (Marsham), the cabbage seedpod weevil. Our study was undertaken to compare the population structure of C. neglectus in North America to that of C. obstrictus, which, in contrast, was introduced only recently to North America and might be expected to have a simpler population structure. We also compared the population structure of C. neglectus to that of Pissodes strobi (Peck), which is known to possess high levels of intraspecific variation and is also a Nearctic weevil. We sequenced a 790-bp fragment of mtDNA (cytochrome oxidase I (COI) gene) and a 117-bp fragment of nuclear DNA (internal transcribed spacer region 1 (ITS1)). Nested clade analysis inferred contiguous range expansion and restricted gene flow with isolation by distance. Analysis of molecular variance also supported restricted gene flow between geographically distant populations. However, within-species variation in C. neglectus was lower than that for other weevil species including C. obstrictus. We also examined DNA divergences and phylogenetic relationships among 10 species of Ceutorhynchus using parsimony analysis of a 2.3-kb fragment of mtDNA (COI–COII) and a 541-bp fragment of nuclear DNA (elongation factor 1α).

Genetic Markers and Quantitative Genetic Variation in Medicago truncatula (Leguminosae): A Comparative Analysis of Population Structure

Genetics ◽  
1996 ◽  
Vol 143 (4) ◽  
pp. 1795-1805 ◽  
Author(s):  
Isabelle Bonnin ◽  
Jean-Marie Prosperi ◽  
Isabelle Olivieri
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Genetic Markers ◽  
Medicago Truncatula ◽  
Random Amplified Polymorphic Dna ◽  
Population Level ◽  
Components Of Variance ◽  
Quantitative Characters ◽  
Marker Loci ◽  
The Face

Abstract Two populations of the selfing annual Medicago truncatula Gaertn. (Leguminoseae), each subdivided into three subpopulations, were studied for both metric traits (quantitative characters) and genetic markers (random amplified polymorphic DNA and one morphological, single-locus marker). Hierarchical analyses of variance components show that (1) populations are more differentiated for quantitative characters than for marker loci, (2) the contribution of both within and among subpopulations components of variance to overall genetic variance of these characters is reduced as compared to markers, and (3) at the population level, within population structure is slightly but not significantly larger for markers than for quantitative traits. Under the hypothesis that most markers are neutral, such comparisons may be used to make hypotheses about the strength and heterogeneity of natural selection in the face of genetic drift and gene flow. We thus suggest that in these populations, quantitative characters are under strong divergent selection among populations, and that gene flow is restricted among populations and subpopulations.

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