scholarly journals Population Genetic Structure of Aphis gossypii Glover (Hemiptera: Aphididae) in Korea

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 319
Author(s):  
Nam ◽  
Park ◽  
Lee

Aphis gossypii Glover (Hemiptera: Aphididae) is a serious polyphagous agricultural pest worldwide. In the present study, we used eight microsatellite markers to investigate the genetic structure and diversity of A. gossypii populations in Korea. Samples were collected from 37 locations in Korea (18 populations in 2016, 14 populations in 2017, and five populations in 2018) from pepper plants. A. gossypii had low to moderate genetic diversity, and expected heterozygosity (HE) ranged from 0.354 to 0.719. A Mantel test of isolation by distance indicated no relationship between genetic structure and geographic distance among all populations (r2 = 0.0004, p = 0.370), suggesting high gene flow among populations in Korea. Populations of A. gossypii in Korea were divided into two distinct genetic clusters (ΔK = 2). In 2016 and 2017, the genetic clusters changed into opposite genetic structures within one year mostly in northwest and southeast parts of Korea. Possible relevance of study results was discussed. Chemical control, cyclical parthenogenesis, and immigrants from the exterior might have resulted in this low genetic diversity and opposite genetic clusters.

2010 ◽  
Vol 100 (5) ◽  
pp. 521-527 ◽  
Author(s):  
K.M. Mikac ◽  
N.N. FitzSimmons

AbstractMicrosatellite markers were used to investigate the genetic structure among invasive L. decolor populations from Australia and a single international population from Kansas, USA to determine patterns of dispersal. Six variable microsatellites displayed an average of 2.5–4.2 alleles per locus per population. Observed (HO) heterozygosity ranged from 0.12–0.65 per locus within populations; but, in 13 of 36 tests, HO was less than expected. Despite low levels of allelic diversity, genetic structure estimated as θ was significant for all pairwise comparisons between populations (θ=0.05–0.23). Due to suspected null alleles at four loci, ENA (excluding null alleles) corrected FST estimates were calculated overall and for pairwise population comparisons. The ENA-corrected FST values (0.02–0.10) revealed significant overall genetic structure, but none of the pairwise values were significantly different from zero. A Mantel test of isolation by distance indicated no relationship between genetic structure and geographic distance among all populations (r2=0.12, P=0.18) and for Australian populations only (r2=0.19, P=0.44), suggesting that IBD does not describe the pattern of gene flow among populations. This study supports a hypothesis of long distance dispersal by L. decolor at moderate to potentially high levels.


2020 ◽  
Vol 68 (5) ◽  
pp. 384
Author(s):  
William Higgisson ◽  
Dianne Gleeson ◽  
Linda Broadhurst ◽  
Fiona Dyer

Gene flow is a key evolutionary driver of spatial genetic structure, reflecting demographic processes and dispersal mechanisms. Understanding how genetic structure is maintained across a landscape can assist in setting conservation objectives. In Australia, floodplains naturally experience highly variable flooding regimes that structure the vegetation communities. Flooding plays an important role, connecting communities on floodplains and enabling dispersal via hydrochory. Water resource development has changed the lateral-connectivity of floodplain-river systems. One possible consequence of these changes is reduced physical and subsequent genetic connections. This study aimed to identify and compare the population structure and dispersal patterns of tangled lignum (Duma florulenta) and river cooba (Acacia stenophylla) across a large inland floodplain using a landscape genetics approach. Both species are widespread throughout flood prone areas of arid and semiarid Australia. Tangled lignum occurs on floodplains while river cooba occurs along rivers. Leaves were collected from 144 tangled lignum plants across 10 sites and 84 river cooba plants across 6 sites, on the floodplain of the lower and mid Lachlan River, and the Murrumbidgee River, NSW. DNA was extracted and genotyped using DArTseq platforms (double digest RADseq). Genetic diversity was compared with floodplain-river connection frequency, and genetic distance (FST) was compared with river distance, geographic distance and floodplain-river connection frequency between sites. Genetic similarity increased with increasing floodplain-river connection frequency in tangled lignum but not in river cooba. In tangled lignum, sites that experience more frequent flooding had greater genetic diversity and were more genetically homogenous. There was also an isolation by distance effect where increasing geographic distance correlated with increasing genetic differentiation in tangled lignum, but not in river cooba. The distribution of river cooba along rivers facilitates regular dispersal of seeds via hydrochory regardless of river level, while the dispersal of seeds of tangled lignum between patches is dependent on flooding events. The genetic impact of water resource development may be greater for species which occur on floodplains compared with species along river channels.


2016 ◽  
Vol 58 (2) ◽  
pp. 71-82 ◽  
Author(s):  
Wojciech Paul ◽  
Elżbieta Cieślak ◽  
Michał Ronikier ◽  
Grzegorz Migdałek ◽  
Aneta Słomka ◽  
...  

AbstractViola uliginosa(bog violet) is a declining species throughout its range due to – mostly anthropogenic – drying out of the wet habitats it occupies. Using AFLP markers, we aimed to estimate the genetic diversity in Polish populations, that may give an insight into the situation of plant populations facing rapid loss of natural habitats.Bog violet from several dispersed Polish populations is generally characterized by very low genetic diversity (HT= 0.048), even lower than several other endangered violets; therefore, we suggest that it should preserve at least EN rank in the red lists/red data books. The mean gene diversity within all populations (HS) was much lower than gene diversity (GST) between populations (0.020 versus 0.583, respectively) which supports the prevalence of clonal propagation of the species (mainly by stolons) but may also point to some significance of autogamy in cleisto- and chasmogamous flowers. A highFSTvalue and the Mantel test for all populations revealed significant isolation by distance. Geographically neighboring pairs of populations formed genetic clusters supported by all (in the case of two closest populations) or most statistical analyses applied. Special attention should be paid to thelocus classicusof the species in Rząska, consisting of a small number of individuals, forming a genetically distinct group, revealing very low gene diversity (Hj= 0.009) and the longest genetic distance to the remaining populations. Our results can contribute to planning future protection measures for the species at this and other locations. Genetic structure of the studied populations suggests local affinities of populations but does not generally support hypothesized recent continuity ofV. uliginosarange along the river valleys of southern Poland; this view may, however, be altered with widening of the scope of studied populations and chosen molecular markers.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243999
Author(s):  
Ke-Xin Zhu ◽  
Shan Jiang ◽  
Lei Han ◽  
Ming-Ming Wang ◽  
Xing-Ya Wang

The rice stem borer (RSB), Chilo suppressalis (Lepidoptera: Pyralidae), is an important agricultural pest that has caused serious economic losses in the major rice-producing areas of China. To effectively control this pest, we investigated the genetic diversity, genetic differentiation and genetic structure of 16 overwintering populations in the typical bivoltine areas of northern China based on 12 nuclear microsatellite loci. Moderate levels of genetic diversity and genetic differentiation among the studied populations were detected. Neighbour-joining dendrograms, Bayesian clustering and principal coordinate analysis (PCoA) consistently divided these populations into three genetic clades: western, eastern and northern/central. Isolation by distance (IBD) and spatial autocorrelation analyses demonstrated no correlation between genetic distance and geographic distance. Bottleneck analysis illustrated that RSB populations had not undergone severe bottleneck effects in these regions. Accordingly, our results provide new insights into the genetic relationships of overwintering RSB populations and thus contribute to developing effective management strategies for this pest.


2020 ◽  
Vol 145 (5) ◽  
pp. 289-298
Author(s):  
Tiantian Zhao ◽  
Wenxu Ma ◽  
Qinghua Ma ◽  
Zhen Yang ◽  
Lisong Liang ◽  
...  

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.


Caryologia ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 141-150
Author(s):  
Bo Shi ◽  
Majid Khayatnezhad ◽  
Abdul Shakoor

One of the most crucial aspects of biological diversity for conservation strategies is genetic diversity, particularly in rare and narrow endemic species. Our study is the first attempt to utilize SCoT markers to check the genetic diversity in Iran. We used 115 plant samples. Our objectives were 1) to check genetic diversity among Geranium species 2) Genetic structure of the Geranium 3) Do the Geranium species exchange genes? 4) To detect isolation by distance among the Geranium species. We used traditional morphological and molecular methods to assess genetic diversity and genetic structure in the Geranium species. A total of 129 amplified polymorphic bands were generated across 13 Geranium species. The size of the amplified fragments ranged from 150 to 3000 bp. G. stepporum showed the highest values for the effective number of alleles (Ne = 1.30) and Shannon information index (I =0.35). Significant ANOVA results (P <0.01) showed differences in quantitative morphological characters in plant species. G. sylvaticum showed high genetic diversity. Mantel test showed a significant correlation (r = 0.17, p=0.0002) between genetic distance and geographical distance, so isolation by distance (IBD) occurred among the Geranium species. According to the SCoT markers analysis, G. kotschyi and G. dissectum had the lowest similarity, and the species of G. sylvaticum and G. pratense had the highest similarity. The present study revealed that a combination of morphological and SCoT methods could distinguish the species of Geranium.


2021 ◽  
Vol 50 (2) ◽  
pp. 405-412
Author(s):  
Pragga Saha Sharmi ◽  
Md Abul Kashem ◽  
Rifat Samad ◽  
Mohammad Zabed Hossain

Fragmentation and reduction of natural population size render threats to the conservation of forest resources through depletion of genetic diversity. Hence, information on genetic structure of Sal (Shorea robusta Roxb. ex Gaertn.) populations is relevant for proper management and conservation of the tropical deciduous forests. The present study focused on assessing the genetic diversity of the populations of Sal which was the dominant tree species of the deciduous forests of Bangladesh. Plant leaf samples were collected from the three populations of Sal distributed in the three geographical regions including Madhupur tract in the districts Tangail and Gazipur and that of the districts of Cumilla and Dinajpur. DNA band profiles were generated using eight ISSR primers for a total of 13 samples taken from the three populations. Statistical analysis was done using PopGen 32 and GenAlEx 6.5 softwares. Principal coordinate analysis done on the DNA band profiles revealed that Sal populations of Madhupur tract and Cumilla positioned nearby while Dinajpur showed maximum genetic distance with that of Cumilla. Mantel test showed significant (p=0.05) correlation between genetic and geographic distances indicating “Isolation by Distance”. Data of the present study indicated higher genetic polymorphism (68.87%) in the Sal population of Madhupur tract compared to other two populations. Small population size of Sal of Dinajpur forest might be related with its low genetic diversity. Data of the present study suggest immediate attention for the conservation of Sal forests in Bangladesh before further genetic erosion occurs. Bangladesh J. Bot. 50(2): 405-412, 2021 (June)


Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
Da Wang ◽  
Xiaoqin Shi ◽  
Deguang Liu ◽  
Yujing Yang ◽  
Zheming Shang

Host plant affinity and geographic distance can play critical roles in the genetic divergence of insect herbivores and evolution of insect biotypes, but their relative importance in the divergence of insect populations is still poorly understood. We used microsatellite markers to test the effects of host plant species and geographic distance on divergence of two biotypes of the English grain aphid, Sitobion avenae (Fabricius). We found that clones of S. avenae from western provinces (i.e., Xinjiang, Gansu, Qinghai and Shaanxi) had significantly higher genetic diversity than those from eastern provinces (i.e., Anhui, Henan, Hubei, Zhejiang and Jiangsu), suggesting their differentiation between both areas. Based on genetic diversity and distance estimates, biotype 1 clones of eastern provinces showed high genetic divergence from those of western provinces in many cases. Western clones of S. avenae also showed higher genetic divergence among themselves than eastern clones. The Mantel test identified a significant isolation-by-distance (IBD) effect among different geographic populations of S. avenae, providing additional evidence for a critical role of geography in the genetic structure of both S. avenae biotypes. Genetic differentiation (i.e., FST) between the two biotypes was low in all provinces except Shaanxi. Surprisingly, in our analyses of molecular variance, non-significant genetic differentiation between both biotypes or between barley and wheat clones of S. avenae was identified, showing little contribution of host-plant associated differentiation to the divergence of both biotypes in this aphid. Thus, it is highly likely that the divergence of the two S. avenae biotypes involved more geographic isolation and selection of some form than host plant affinity. Our study can provide insights into understanding of genetic structure of insect populations and the divergence of insect biotypes.


2021 ◽  
Author(s):  
Zhu Ren ◽  
Hong He ◽  
Yang Zhang ◽  
Xu Su

Abstract Studying the population genetic structure of both parasites and their host-plants is expected to yield new valuable insights into their coevolution. In this study, we examined and compared the population genetic diversity and structure of 12 populations of the Rhus gall aphid, Schlechtendalia chinensis, and its host-plant, Rhus chinensis, using amplified fragment length polymorphism (AFLP) markers. AMOVA analysis showed that the genetic variance of the aphid and its host-plant were both higher within populations compared to that among them, suggesting that a co-evolutionary history has yielded similar patterns of population genetic structure. We did not detect significant correlation between genetic and geographic distance for either the aphid or host-plant populations, therefore rejecting an isolation by distance model for the demographic histories of the two species. However, our results appeared to suggest that genetically diverse host -plant Rhus populations correlated to similarly genetically diverse populations of gall aphid parasites.


2021 ◽  
Vol 49 (3) ◽  
pp. 12407
Author(s):  
Ting WANG ◽  
Zhen WANG ◽  
Shufeng LI ◽  
Zhanming YING ◽  
Xiaoxian RUAN ◽  
...  

Spatial genetic variation involves spatial genetic structure (SGS) and genetic diversity is important genetic features of plants. We first evaluated spatial genetic structure (SGS) and genetic diversity among four populations of Alsophila gigantea from Hainan Island, China, using inter-simple sequence repeat (ISSR) markers. Significant but weak FSGS was found in A. gigantea. High genetic diversity was identified at the species level and the population level. AMOVA analysis revealed a low level of genetic differentiation among the four populations with high gene flow. Mantel test showed no significant correlation between genetic distance and geographic distance. It was found that association between annual mean temperature and annual precipitation with FSGS. Combined with these spatial genetic variation, abundant precipitation and suitable temperature create a stable environment for A. gigantea in Hainan Island, which allows the fern to expand rapidly during the LGM. These results further emphasized the role of outcrossing, and history and environmental factors in the evolution of A. gigantea. This study also provided new insights on in local adaptation of A. gigantea to environmental fluctuations, and available genetic data to enhance the conservation for relict tree ferns.


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