scholarly journals Genetic Diversity and Population Structure of Natural Lycorma delicatula (White) (Hemiptera: Fulgoridea) Populations in China as Revealed by Microsatellite and Mitochondrial Markers

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 312 ◽  
Author(s):  
Li Zhang ◽  
Wenhui Zhao ◽  
Fuping Wang ◽  
Daozheng Qin

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), is a polyphagous pest originating in China and now widely distributed in Asian countries. This is one of the more serious forestry pests with a broad host range and causes significant economic losses. Molecular comparison has been used to investigate this pest’s origin in China, and recent studies have explored the genetic structure among populations in Korea. However, the population structure of this pest in China remains poorly understood. In this study, 13 microsatellite markers and two mitochondrial markers (from nicotinamide adenine dinucleotid (NADH) dehydrogenase subunit 2 (ND2) and NADH dehydrogenase subunit 6 (ND6) regions) were used to reveal the origins and dispersal of L. delicatula based on a genetic analysis of Chinese populations from eight locations. Results show a low to high level of genetic differentiation among populations and significant genetic differentiation between both two clusters and four clusters. The network and phylogenetic analyses for mitochondrial haplotypes and population structure analyses for microsatellite datasets suggest that there is potential gene flow between geographical populations. The populations from Zhejiang and Fujian provinces may come from the other geographical populations in north China. The populations from Beijing, Henan, and Anhui provinces were regarded as the major source of migrants with a high number of migrants leaving (the effective number of migrants (Nem) = 24.40) and the low number of migrants entering (Nem = 2.05) based on the microsatellite dataset, where significant asymmetrical effective migrants to the other populations were detected by non-overlapping 95% confidence intervals.

2018 ◽  
Author(s):  
Rui Zang ◽  
Ying Zhao ◽  
Kangdi Guo ◽  
Kunqi Hong ◽  
Huijun Xi ◽  
...  

AbstractThe bitter gourd fusarium wilt caused by Fusarium oxysporum f.sp. momordicae (FOM) was a devastating disease in China and leading to great economic losses every year. A total of 152 isolates, which have the typical Fusarium oxysporum characteristics with abundant microconidia and macroconidia on the white or ruby colonies, were obtained from diseased plant tissues with typical fusarium wilt symptoms. The BLASTn analysis of rDNA-ITS showed 99% identity with F.oxysporum species. Among the tested isolates, three isolates infected tower gourd, and five isolates were pathogenic to bottle gourd. However, they were all pathogenic to bitter gourd. Based on the molecular and morphologic results, the isolates were identified as FOM. For genetic variation analysis, forty ISSR primers were screened and eleven primers were used in PCR amplification. Totally, 121 loci were detected, of which 52 loci were polymorphic at rate of 42.98%. The POPGENE analysis showed that Nei’s gene diversity index (H) and Shannon’s information index (I) were 0.0902 and 0.1478, respectively, which indicated that the genetic diversity for the tested 152 isolates was relatively low. It also means that each geographical population was a relatively independent unit. While the value of coefficient of gene differentiation (Gst=0.4929 > 0.15) pointed to the genetic differentiation was mainly among populations. The strength of gene flow (Nm=0.5143<1.0) was weaker, indicating that gene exchanges were blocked to some degree. The dendrogram based on ISSR markers showed that the eight geographical populations were clustered into four groups at the threshold of genetic similar coefficient 0.96. Fujian, Jiangxi and Guangdong populations were clustered into Group I. Group II contained Hunan and Guangxi populations. Group III only had Hainan population. Group IV consisted Shandong and Henan populations. The geographical populations closer to each other grouped together, suggesting a correlationship between geographical origin and genetic differentiation. Two hybridization events were observed between Hainan and Hunan populations and between Guangdong and Guangxi by Structure analysis. Our findings enrich the knowledge on genetic variation characteristics of the FOM populations with helpful of development of effective disease management programs and disease resistance breeding.


1997 ◽  
Vol 75 (10) ◽  
pp. 1707-1713 ◽  
Author(s):  
Rimvydas Vasiliauskas ◽  
Jan Stenlid

Population structure and genetic variation in Nectria fuckeliana Booth isolated from Picea abies (L.) Karst. in Sweden and Lithuania was studied using somatic incompatibility tests and DNA fingerprinting. All incompatibility pairings between different isolates of N. fuckeliana resulted in demarcation zones; thus, no vegetative compatibility groups were detected. Each isolate was distinguishable from all other isolates on the basis of banding patterns produced by amplification of DNA using the M13 primer. No country-specific markers were observed. Principal component analysis of amplified banding patterns separated the isolates from Sweden and Lithuania into two clusters, showing genetic differentiation between the geographical populations across the Baltic sea. An analysis of similarity matrix, calculated by the program SIMQUAL from the numerical taxonomy package NTSYS-pc, confirmed the separation of the isolates into the two groups. Low genetic differentiation was revealed within both the Swedish and Lithuanian geographical populations of the fungus. Local distances in the forest stand (100 m) had no influence on the genetic similarity of the N. fuckeliana isolates (R2 = 0.003). Key words: Nectria fuckeliana, DNA fingerprinting, genetic variation, somatic incompatibility, population structure.


Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 409-421 ◽  
Author(s):  
Cheryl A Wise ◽  
Michaela Sraml ◽  
Simon Easteal

Abstract To test whether patterns of mitochondrial DNA (mtDNA) variation are consistent with a neutral model of molecular evolution, nucleotide sequences were determined for the 1041 bp of the NADH dehydrogenase subunit 2 (ND2) gene in 20 geographically diverse humans and 20 common chimpanzees. Contingency tests of neutrality were performed using four mutational categories for the ND2 molecule: synonymous and nonsynonymous mutations in the transmembrane regions, and synonymous and nonsynonymous mutations in the surface regions. The following three topological mutational categories were also used: intraspecific tips, intraspecific interiors, and interspecific fixed differences. The analyses reveal a significantly greater number of nonsynonymous polymorphisms within human transmembrane regions than expected based on interspecific comparisons, and they are inconsistent with a neutral equilibrium model. This pattern of excess nonsynonymous polymorphism is not seen within chimpanzees. Statistical tests of neutrality, such as Tajima's D test, and the D and F tests proposed by Fu and Li, indicate an excess of low frequency polymorphisms in the human data, but not in the chimpanzee data. This is consistent with recent directional selection, a population bottleneck or background selection of slightly deleterious mutations in human mtDNA samples. The analyses further support the idea that mitochondrial genome evolution is governed by selective forces that have the potential to affect its use as a “neutral” marker in evolutionary and population genetic studies.


Parasitology ◽  
2004 ◽  
Vol 130 (2) ◽  
pp. 239-246 ◽  
Author(s):  
J.-Y. CHUNG ◽  
W.-G. KHO ◽  
S.-Y. HWANG ◽  
E.-Y. JE ◽  
Y.-T. CHUNG ◽  
...  

Acephalic cysticercus (Ac), a rarely developed multilobulated and nonencysted form of larval Taenia, causes hydrocephalus or adhesive arachnoiditis in the ventricles and subarachnoidal space that often lead to fatal outcome in affected patients. Ac has been proposed to originate from T. solium on the basis of morphological features, while no molecular data supporting the presumption have been available. In the present study, we investigated the immunological properties as well as molecular characteristics of Ac that was obtained surgically from 6 patients. Immunoblotting of the cyst fluid from Ac samples demonstrated the constitutive expression of a T. solium metacestode (TsM) 10 kDa protein. Specific antibodies against the truncated 10 kDa protein, which appears to be species specific for TsM cysticercosis, were detected in both serum and cerebrospinal fluid samples of Ac patients. Nucleotide sequences of mitochondrial cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 1 (ND1) genes of Ac were almost identical to those of T. solium but differed substantially from those of the other Taenia species. In phylogenetic analysis, Ac clustered with T. solium in a well-supported clade. Our results strongly suggest that Ac may have originated from T. solium.


2017 ◽  
Vol 4 (1) ◽  
pp. 11
Author(s):  
Ketut Sugama ◽  
Agus Prijono

Four populations of milkfish (Chanos chanos ) were collected (N=100) from coastal water of  Aceh. Bali, East Java and South Sulawesi and were examined electrophoretically at 29 loci to deterurine the genetic vuriability and the population structure.


2021 ◽  
Vol 12 ◽  
Author(s):  
Tian-Qi Shi ◽  
Hai-Mo Shen ◽  
Shen-Bo Chen ◽  
Kokouvi Kassegne ◽  
Yan-Bing Cui ◽  
...  

Malaria incidence has declined dramatically over the past decade and China was certified malaria-free in 2021. However, the presence of malaria in border areas and the importation of cases of malaria parasites are major challenges for the consolidation of the achievements made by China. Plasmodium vivax Duffy binding protein (PvDBP) performs a significant role in erythrocyte invasion, and is considered a promising P. vivax vaccine. However, the highly polymorphic region of PvDBP (PvDBP-II) impedes the development of blood-stage vaccine against P. vivax. In this study, we investigated the genetic diversity and natural selection of PvDBP-II among 124 P. vivax isolates collected from the China-Myanmar border (CMB) in Yunnan Province, China, during 2009–2011. To compare genetic diversity, natural selection, and population structure with CMB isolates, 85 pvdbp-II sequences of eastern Myanmar isolates were obtained from GenBank. In addition, global sequences of pvdbp-II were retrieved from GenBank to establish genetic differentiation relationships and networks with the CMB isolates. In total, 22 single nucleotide polymorphisms reflected in 20 non-synonymous and two synonymous mutations were identified. The overall nucleotide diversity of PvDBP-II from the 124 CMB isolates was 0.0059 with 21 haplotypes identified (Hd = 0.91). The high ratio of non-synonymous to synonymous mutations suggests that PvDBP-II had evolved under positive selection. Population structure analysis of the CMB and eastern Myanmar isolates were optimally grouped into five sub-populations (K = 5). Polymorphisms of PvDBP-II display that CMB isolates were genetically diverse. Mutation, recombination, and positive selection promote polymorphism of PvDBP-II of P. vivax population. Although low-level genetic differentiation in eastern Myanmar was identified along with the more effective malaria control measures, the complexity of population structure in malaria parasites has maintained. In conclusion, findings from this study advance knowledge of the understanding of the dynamic of P. vivax population, which will contribute to guiding the rational design of a PvDBP-II based vaccine.


2021 ◽  
Author(s):  
◽  
Luke Thomas

<p>Understanding patterns of gene flow across a species range is a vital component of an effective fisheries management strategy. The advent of highly polymorphic microsatellite markers has facilitated the detection of fine-scale patterns of genetic differentiation at levels below the resolving power of earlier techniques. This has triggered the wide-spread re-examination of population structure for a number of commercially targeted species. The aims of thesis were to re-investigate patterns of gene flow of the red rock lobster Jasus edwardsii throughout New Zealand and across the Tasman Sea using novel microsatellite markers. Jasus edwardsii is a keystone species of subtidal rocky reef system and supports lucrative export markets in both Australia and New Zealand. Eight highly polymorphic microsatellite markers were developed from 454 sequence data and screened across a Wellington south coast population to obtain basic diversity indices. All loci were polymorphic with the number of alleles per locus ranging from 6-39. Observed and expected heterozygosity ranged from 0.563-0.937 and 0.583-0.961, respectively. There were no significant deviations from Hardy-Weinberg equilibrium following standard Bonferroni corrections. The loci were used in a population analysis of J. edwardsii that spanned 10 degrees of latitude and stretched 3,500 km across the South Pacific. The analysis rejected the null-hypothesis of panmixia based on earlier mDNA analysis and revealed significant population structure (FST=0.011, RST=0.028) at a wide range of scales. Stewart Island was determined to have the highest levels of genetic differentiation of all populations sampled suggesting a high degree of reproductive isolation and self-recruitment. This study also identified high levels of asymmetric gene flow from Australia to New Zealand indicating a historical source-sink relationship between the two countries. Results from the genetic analysis were consistent with results from oceanographic dispersal models and it is likely that the genetic results reflect historical and contemporary patterns of Jasus edwardsii dispersal and recruitment throughout its range.</p>


Agromet ◽  
2019 ◽  
Vol 33 (1) ◽  
pp. 41-51
Author(s):  
. Misnawati ◽  
Mega Perdanawanti

Extreme climate events have significant impacts on various sectors such as agriculture, ecosystem, health and energy. The issue would lead to economic losses as well as social problems. This study aims to investigate the trend of extreme precipitation in Sumatera Island based on observed data during 30-year period, 1981–2010. There are ten indices of climate extreme as defined by ETCCDMI, which were tested in this study, including PRCPTOT, SDII, CDD, CWD, R10, R50, R95p, R99p, Rx1day and Rx5day. Then, the trend was analyzed based on the Mann-Kendall statistic, performed on the time series of precipitation data. The result shows that there was positive trend of extreme precipitation found in most stations over Sumatera, either statistically significant or insignificant. In each extreme precipitation indices, the number of observed stations indicating the insignificant change is higher than the significant one. This research also found that some indices including SDII, Rx1day, R50, R95p and R99p, showed a significantly-positive trend followed by a higher intensity of wetter and heavier events of extreme precipitation over Sumatera. On the other hand, the wet spell (CWD) index shows a negative trend (α=0.05).


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