Genetic variation and population structure of different geographical populations of Meretrix petechialis based on mitochondrial gene COI

2019 ◽  
Vol 98 (3) ◽  
Author(s):  
Jun-Hong Zheng ◽  
Hong-Tao Nie ◽  
Feng Yang ◽  
Xi-Wu Yan
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Mitochondrial Gene ◽  
Gene Coi ◽  
Geographical Populations ◽  
Meretrix Petechialis

Genetic diversity and population structure of the rice false smut pathogen Ustilaginoidea virens in Sichuan-Chongqing region

Plant Disease ◽  
2021 ◽  
Author(s):  
Anfei Fang ◽  
Zhuangyuan Fu ◽  
Zexiong Wang ◽  
Yuhang Fu ◽  
Yubao Qin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Recombination ◽  
Resistance Breeding ◽  
Ustilaginoidea Virens ◽  
Breeding Lines ◽  
Rice False Smut ◽  
Geographical Populations ◽  
False Smut

Rice false smut caused by Ustilaginoidea virens is currently one of the most devastating fungal diseases of rice panicles worldwide. In this study, two novel molecular markers derived from SNP-rich genomic DNA fragments and a previously reported molecular marker were used for analyzing the genetic diversity and population structure of 167 U. virens isolates collected from nine areas in Sichuan-Chongqing region, China. A total of 62 haplotypes were identified, and a few haplotypes with high frequency were found and distributed in two to three areas, suggesting gene flow among different geographical populations. All isolates were divided into six genetic groups. The groups Ⅰ and Ⅵ were the largest including 61 and 48 isolates, respectively. The pairwise FST values showed significant genetic differentiation among all compared geographical populations. AMOVA showed that intergroup genetic variation accounted for 40.17% of the total genetic variation, while 59.83% of genetic variation came from intragroup. The UPGMA dendrogram and population structure revealed that the genetic composition of isolates collected from ST (Santai), NC (Nanchong), YC (Yongchuan), and WS (Wansheng) dominated by the same genetic subgroup was different from those collected from other areas. In addition, genetic recombination was found in a few isolates. These findings will help to improve the strategies for rice false smut management and resistance breeding, such as evaluating breeding lines with different isolates or haplotypes at different elevations and landforms.

Population structure and genetic variation in Nectria fuckeliana

1997 ◽  
Vol 75 (10) ◽  
pp. 1707-1713 ◽  
Author(s):  
Rimvydas Vasiliauskas ◽  
Jan Stenlid
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Genetic Differentiation ◽  
Dna Fingerprinting ◽  
Principal Component ◽  
Banding Patterns ◽  
Vegetative Compatibility Groups ◽  
Somatic Incompatibility ◽  
Geographical Populations ◽  
The Baltic

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.

scholarly journals Determining Whether Geographic Origin and Potato Genotypes Shape the Population Structure of Phytophthora infestans in the Central Region of Colombia

2019 ◽  
Vol 109 (1) ◽  
pp. 145-154
Author(s):  
Sandra Catalina Chaves ◽  
María Camila Rodríguez ◽  
María Fernanda Mideros ◽  
Florencia Lucca ◽  
Carlos E. Ñústez ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Phytophthora Infestans ◽  
Central Region ◽  
Geographic Origin ◽  
Geographic Area ◽  
Potato Cultivars ◽  
Clonal Lineage ◽  
Host Genotype ◽  
Genetic Population

Pathogen variation plays an important role in the dynamics of infectious diseases. In this study, the genetic variation of 279 Phytophthora infestans isolates was assessed using a combination of 12 microsatellite simple-sequence repeat markers. Isolates were collected from 11 different potato cultivars in 11 different geographic localities of the central region of Colombia. The objective of this study was to determine whether populations were differentiated by host genotype or geographic origin. Within a single clonal lineage, EC-1, 76 genotypes were detected. An analysis of molecular variance attributed most of the variation to differences within host genotypes rather than among the host genotypes, suggesting that host cultivars do not structure the populations of the pathogen. Furthermore, the lack of a genetic population structure according to the host cultivar was confirmed by all of the analyses, including the Bayesian clustering analysis and the minimum spanning network that used the Bruvo genetic distance, which suggested that there are no significant barriers to gene flow for P. infestans among potato cultivars. According to the geographic origin, the populations of P. infestans were also not structured, and most of the variation among the isolates was attributed to differences within localities. Only some but not all localities in the north and west of the central region of Colombia showed some genetic differentiation from the other regions. The absence of sexual reproduction of this pathogen in Colombia was also demonstrated. Important insights are discussed regarding the genetic population dynamics of the P. infestans populations of the central region of Colombia that were provided by the results. In Colombia, there is a high genetic variation within the EC-1 clonal lineage with closely related genotypes, none dominant, that coexist in a wide geographic area and on several potato cultivars.

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