scholarly journals Molecular Diversity and Evolutionary Processes of Alternaria solani in Brazil Inferred Using Genealogical and Coalescent Approaches

2009 ◽  
Vol 99 (6) ◽  
pp. 765-774 ◽  
Author(s):  
Valdir Lourenço ◽  
Andrés Moya ◽  
Fernando González-Candelas ◽  
Ignazio Carbone ◽  
Luiz A. Maffia ◽  
...  
Keyword(s):  
Gene Flow ◽  
Nucleotide Diversity ◽  
Early Blight ◽  
Balancing Selection ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Alternaria Solani ◽  
Interesting Case ◽  
Evolutionary Processes ◽  
Tomato Plants

Alternaria spp. form a heterogeneous group of saprophytic and plant-pathogenic fungi widespread in temperate and tropical regions. However, the relationship between evolutionary processes and genetic diversity with epidemics is unknown for several plant-pathogenic Alternaria spp. The interaction of Alternaria solani populations with potato and tomato plants is an interesting case study for addressing questions related to molecular evolution of an asexual fungus. Gene genealogies based on the coalescent process were used to infer evolutionary processes that shape the A. solani population. Sequences of the rDNA internal transcribed spacer (ITS) region and the genes which encode the allergenic protein alt a 1 (Alt a 1) and glyceraldehyde-3-phosphate dehydrogenase (Gpd) were used to estimate haplotype and nucleotide diversity as well as for the coalescent analyses. The highest number of parsimony informative sites (n = 14), nucleotide diversity (0.007), and the average number of nucleotide differences (3.20) were obtained for Alt a 1. Although the highest number of haplotypes (n = 7) was generated for ITS, haplotype diversity was the lowest (0.148) for this region. Recombination was not detected. Subdivision was inferred from populations associated with hosts but there was no evidence of geographic subdivision, and gene flow is occurring among subpopulations. In the analysis of the Alt a 1, balancing selection and population expansion or purifying selection could have occurred in A. solani subpopulations associated with potato and tomato plants, respectively. There is strong evidence that the subpopulation of A. solani that causes early blight in potato is genetically distinct from the subpopulation that causes early blight in tomato. The population of A. solani is clonal, and gene flow and mutation are the main evolutionary processes shaping its genetic structure.

scholarly journals Diversitas Genetika dan Identifikasi Jenis Kelamin Burung Pelikan (Pelecanus conspicillatus Temminck, 1824) di Penangkaran Taman Margasatwa Ragunan Jakarta

2021 ◽  
Vol 17 (2) ◽  
pp. 105-114
Author(s):  
Anik Budhi Dharmayanthi ◽  
Achmad Muchsinin ◽  
Afriana Pulungan ◽  
Moch Syamsul Arifin Zein
Keyword(s):  
Genetic Diversity ◽  
Nucleotide Diversity ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Bird Populations ◽  
Low Genetic Diversity ◽  
In Captivity ◽  
D Loop ◽  
Haplotype 1

Pelicans (Pelecanus conspicillatus) is one of the wild species that have a widely distribution. This bird has been successfully bred in Ragunan Zoo, Jakarta. The indicator of inbreeding in the captive population is shown by the decrease of nucleotide diversity and number of haplotypes. The result of genetic diversity analysis using D-loop fragment sequences showed low genetic diversity with nucleotide diversity (p) = 0.00064 ± 0.00010 and haplotype diversity (Hd) = 0.532 ± 0.061 in Pelecanus conspicillatus populations in the Ragunan Zoo. However, negative Fu's Fs value (-3,246) indicates population expansion. We found that there were seven haplotypes in bird populations in the captivity: haplotype 1, 2 and 3 consist of 43 individuals (65.15%), five individuals (7.57%), and 14 individuals (21.21%), respectively. For each haplotype 4, 5, 6 and 7 is only represented by one individual of Pelecanus conspicillatus (1.51%). The sex ratio of males to females is 1: 8.86 with four males identified as haplotype 1, and one male on haplotypes 3, 5 and 7, respectively. Genetic diversity data of the population is an important way for designing long-term plans and goals in efforts to maintain genetic diversity of the Pelecanus conspicillatus population in captivity.

scholarly journals Post-Disturbance Genetic Changes: The Impact of the 2010 Mega-Earthquake and Tsunami on Chilean Sandy Beach Fauna

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Antonio Brante ◽  
Garen Guzmán-Rendón ◽  
Erwin M. Barría ◽  
Marie-Laure Guillemin ◽  
Iván Vera-Escalona ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Adult Survival ◽  
Genetic Changes ◽  
Species Response ◽  
Emerita Analoga ◽  
Mtdna Sequence ◽  
The Impact

Abstract Earthquake/tsunamis can have profound impacts on species and their genetic patterns. It is expected that the magnitude of this impact might depend on the species and the time since the disturbance occurs, nevertheless these assumptions remain mostly unexplored. Here we studied the genetic responses of the crustacean species Emerita analoga, Excirolana hirsuticauda, and Orchestoidea tuberculata to the 27F mega-earthquake/tsunami that occurred in Chile in February 2010. mtDNA sequence analyses revealed a lower haplotype diversity for E. analoga and E. hirsuticauda in impacted areas one month after the 27F, and the opposite for O. tuberculata. Three years after the 27F we observed a recovery in the genetic diversity of E. analoga and E. hirsuticauda and decrease in the genetic diversity in O. tuberculata in 2/3 of sampled areas. Emerita analoga displayed decrease of genetic differentiation and increase in gene flow explained by long-range population expansion. The other two species revealed slight increase in the number of genetic groups, little change in gene flow and no signal of population expansion associated to adult survival, rapid colonization, and capacity to burrow in the sand. Our results reveal that species response to a same disturbance event could be extremely diverse and depending on life-history traits and the magnitude of the effect.

scholarly journals Phylogeography of the American Woodcock (Scolopax Minor): Are Management Units Based on Band Recovery Data Reflected in Genetically Based Management Units?

The Auk ◽  
2005 ◽  
Vol 122 (4) ◽  
pp. 1149-1160
Author(s):  
Judith M. Rhymer ◽  
Daniel G. McAuley ◽  
Heather L. Ziel
Keyword(s):  
Gene Flow ◽  
North America ◽  
Haplotype Diversity ◽  
Bird Species ◽  
Population Expansion ◽  
Phylogeographic Structure ◽  
Eastern Region ◽  
Management Units ◽  
American Woodcock ◽  
Scolopax Minor

Abstract Information on population connectivity throughout the annual cycle has become more crucial, because populations of many migratory birds are in decline. One such species is the American Woodcock (Scolopax minor), which inhabits early-successional forests in eastern North America. Although band recoveries have proved useful for dividing populations of this game bird species into an Eastern Region and Central Region for management purposes, these data do not provide enough detail to determine the breeding population of origin of birds recovered on stopover and wintering areas. To obtain more fine-scale data, we undertook a phylogeographic study of American Woodcock populations throughout their primary breeding range in the eastern United States and Canada using mitochondrial DNA (mtDNA) sequences from the hypervariable control region I (CRI) and ND6 gene. Despite high haplotype diversity, nucleotide diversity was low and there was no phylogeographic structure among American Woodcock populations across the species range, with birds from many states and provinces in both management regions sharing identical haplotypes. Results suggest recent or ongoing gene flow among populations, with asymmetric movement of birds between migration flyways. As has been demonstrated for several other avian species in North America, American Woodcock appear to have undergone a rapid population expansion following the late Pleistocene glacial retreat. Thus, a combination of historical demographic factors and recent or ongoing gene flow mask any population structure based on mtDNA that might accrue from philopatry to breeding areas observed in studies of marked birds. Phylogéographie de Scolopax minor: Est-ce que les Unités de Gestion Basées sur les Données de Retour de Bagues Reflètent les Unités de Gestion Basées sur la Génétique?

Molecular Diversity, Haplotype Distribution and Gene Flow of Bipolaris Sorokiniana Fungus Causing Spot Blotch Disease in Different Wheat Growing Zones

2021 ◽  
Author(s):  
Prem Lal Kashyap ◽  
sudheer Kumar ◽  
Anju Sharma ◽  
Ravi Shekhar Kumar ◽  
Sunita Mahapatra ◽  
...  
Keyword(s):  
Gene Flow ◽  
Balancing Selection ◽  
Population Expansion ◽  
Bipolaris Sorokiniana ◽  
Spot Blotch ◽  
Moderate Level ◽  
Common Source ◽  
Source Population ◽  
Internal Transcribed Spacer Region ◽  
Haplotypic Diversity

Abstract Bipolaris sorokiniana (BS) is an economically important fungal pathogen causing spot blotch of wheat (Trtiticum aestivum) and found in all wheat growing zones of India. Very scanty and fragmentary information is available on its genetic diversity. The current research is the first detailed report on the geographic distribution and evolution of BS population in five geographically distinct wheat growing zones [North Western Plain Zone (NWPZ), North Eastern Plain zone (NEPZ); North Hill Zone (NHZ), Southern Hill Zone (SHZ) and Peninsular Zone (PZ)] of India, studied by performing nucleotide sequence comparison of internal transcribed spacer region of 183 isolates. A moderate to high levels of haplotypic diversity was noticed in different wheat growing zones. Phylogenetic analysis suggests that B. sorokiniana exist in two distinct lineages as all isolates under study were grouped in two different clades and found analogous to the findings of haplotypic and median joining network analysis. The genetic parameters revealed the existence of 59 haplotypes with three major haplotypes (H_2, H_3, and H_25) which showed star-like structure network surrounded by several single haplotypes, revealing high frequency of the mutations ((Eta = 2 – 437) in total analyzed population. H_3 was observed as a predominant haplotype and prevalent in all the five zones. Moderate level of genetic differentiation was found between NEPZ and PZ (Fst = 0.563), whereas it was low between NEPZ and NHZ (Fst = -0.062). High level of gene flow was noticed between NWPZ and NEPZ (Nm = 14.32), while it was found minimum between SZ and NHZ (Nm = 0.50). Moreover, negative score of neutrality statistics (Tajima’s D and Fu’s FS test) for NWPZ, PZ and SHZ populations, suggested recent population expansion in these zones. However, positive score for both the neutrality tests observed in NEPZ and NHZ indicated the dominance of balancing selection in structuring their population. Recombination events were observed in the NWPZ, NEPZ and NHZ population, while it was absent in SHZ and PZ population. Thus, the lack of any specific genetic population structure in all the zones indicates for the expansion history only from one common source population i.e. NWPZ, a mega zone of wheat production in India. Overall, it seems that the predominance of individual haplotypes with a moderate level of genetic variation and men mediated movement of contaminated seed and dispersal of inoculum, mutations and recombination as prime evolutionary processes play essential role in defining the genetic structure of BS population.

Antagonistic Potential of Macrolepiota sp. Against Alternaria Solani as Causal Agent of Early Blight Disease in Tomato Plants

2019 ◽  
Vol 72 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Jesús S. Hernández-Ochoa ◽  
Laura N. Levin ◽  
Carlos E. Hernández-Luna ◽  
Juan Francisco Contreras-Cordero ◽  
Guillermo Niño-Medina ◽  
...  
Keyword(s):  
Early Blight ◽  
Alternaria Solani ◽  
Causal Agent ◽  
Tomato Plants ◽  
Antagonistic Potential ◽  
Blight Disease

scholarly journals Fenugreek extract application improves plant performance of Alternaria solani infected tomato plants

2021 ◽  
Vol 58 (04) ◽  
pp. 1263-1275
Author(s):  
Rashid Iqbal Khan
Keyword(s):  
Plant Extracts ◽  
Fungal Pathogens ◽  
Early Blight ◽  
Growth Parameters ◽  
Alternaria Solani ◽  
Plant Performance ◽  
Total Phenolic ◽  
Tomato Plants ◽  
Chlorophyll Pigments

Plant extracts (PE’s) has emerged as a safer alternative to manage the fungal pathogens affecting tomato productivity. The current study aimed to evaluate the antimicrobial potential of methanolic fenugreek extract against Alternaria solani, a causal agent of early blight disease in tomato. Fenugreek extract was used at different concentrations of 5%, 10%, 15%, 20% and 25% under in vitro conditions. Results concluded that 25% fenugreek extract significantly reduced the radial growth (2.5 cm) of A. solani under in vitro conditions. Based on in vitro results, three concentrations (5%, 15% and 25%) of fenugreek extract was examined under greenhouse and field conditions. The outcomes expressed that 5% fenugreek extract reduced the disease severity up to 30.19% under greenhouse conditions and up to 40.53% under field trials. Although, application of fenugreek extract had exhibited non-significant impact on vegetative and reproductive growth parameters. However, its application had proved better results as compared to those plants which are infected with A. solani but received zero application of fenugreek extract. Furthermore, the effectiveness of plant extracts was evaluated by variant photosynthetic, antioxidative, polyphenolic and hypersensitive response of A. solani affected tomato plants. The 25% fenugreek extract application had augmented the chlorophyll pigments along with the significant increment of superoxide dismutase (174.16 U mg-1 protein), peroxidase (7.61 µmol min-1 g-1 protein) and catalase activity (4.73 nmol min-1 g-1 protein). Similar outcomes were observed regarding phenolic compounds, where 5% fenugreek extract application had enhanced flavonoid levels (26.62 mg QuE g-1), tannins (1.28 mg TE g-1 extract) and total phenolic contents (2.39 mg GAE g-1) in tomato leaves demonstrating its protective effect against early blight. In dose response, 25% fenugreek extract was most effective in reducing lipid peroxidation and enhancing H2O2 levels. The outcomes of study exhibited the fenugreek extract as an effective strategy to be used against A. solani to control early blight infection in tomato plants. Thus, it can serve as suitable fungicide alternative for resource-poor agriculture areas mainly in developing countries.

scholarly journals Curvularia Lunata as New Causal Pathogen of Tomato Early Blight Disease in Egypt

2021 ◽  
Author(s):  
Heba-Alla S. AbdElatah ◽  
Nashwa M.A. Sallam ◽  
Mohamed S. Mohamed ◽  
Hadeel M. M. Khalil Bagy
Keyword(s):  
Early Blight ◽  
Alternaria Solani ◽  
Potato Dextrose Agar ◽  
Curvularia Lunata ◽  
Tomato Cultivar ◽  
Tomato Plants ◽  
Fungal Isolates ◽  
Pathogenicity Tests ◽  
Causal Pathogen ◽  
Blight Disease

Abstract Tomato plants displaying early blight symptoms were collected from different localities in the provinces of Assiut and Sohag, Egypt. The causal pathogens were isolated on potato dextrose agar plates. Pathogenicity tests with 48 isolates were carried out under greenhouse conditions on tomato cultivar (CV 844). All tested isolates caused symptoms of early blight disease with different degrees. The highest disease severity on tomato plants was found after inoculation with isolate No. 6 followed by isolates No. 20 and No. 31. The most pathogenic isolates were identified by sequence analysis using ITS1 and ITS4 primers. The analysis of the amplified sequences from fungal isolates No. 6, 20 and 31 displayed 99 - 100% nucleotide identity with Alternaria solani, Curvularia lunata and A. alternata, respectively. To our knowledge, this is the first report of Curvularia lunata as one of the causal pathogens of early blight disease of tomato plants in Egypt.

scholarly journals Population genetic structure of the malaria vector Anopheles minimus in Thailand based on mitochondrial DNA markers

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kamonchanok Bunmee ◽  
Urusa Thaenkham ◽  
Naowarat Saralamba ◽  
Alongkot Ponlawat ◽  
Daibin Zhong ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Malaria Vector ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Anopheles Minimus ◽  
The Past ◽  
Oxidase Subunit

Abstract Background The malaria vector Anopheles minimus has been influenced by external stresses affecting the survival rate and vectorial capacity of the population. Since An. minimus habitats have continuously undergone ecological changes, this study aimed to determine the population genetic structure and the potential gene flow among the An. minimus populations in Thailand. Methods Anopheles minimus was collected from five malaria transmission areas in Thailand using Centers for Disease Control and Prevention (CDC) light traps. Seventy-nine females from those populations were used as representative samples. The partial mitochondrial cytochrome c oxidase subunit I (COI), cytochrome c oxidase subunit II (COII) and cytochrome b (Cytb) gene sequences were amplified and analyzed to identify species and determine the current population genetic structure. For the past population, we determined the population genetic structure from the 60 deposited COII sequences in GenBank of An. minimus collected from Thailand 20 years ago. Results The current populations of An. minimus were genetically divided into two lineages, A and B. Lineage A has high haplotype diversity under gene flow similar to the population in the past. Neutrality tests suggested population expansion of An. minimus, with the detection of abundant rare mutations in all populations, which tend to arise from negative selection. Conclusions This study revealed that the population genetic structure of An. minimus lineage A was similar between the past and present populations, indicating high adaptability of the species. There was substantial gene flow between the eastern and western An. minimus populations without detection of significant gene flow barriers. Graphical abstract

scholarly journals Mineral profiling of resistant and susceptible tomato varieties against Alternaria solani causing early blight

2021 ◽  
Vol 58 (04) ◽  
pp. 1315-1321
Author(s):  
Shafqat Ali
Keyword(s):  
Management Strategy ◽  
Early Blight ◽  
Alternaria Solani ◽  
Resistant Variety ◽  
Mineral Contents ◽  
Tomato Plants ◽  
Structured Design ◽  
Resistant Group ◽  
Susceptible Tomato ◽  
Susceptible Group

The current research was conducted to investigate the alterations in the mineral status in the leaves of tomato plants against early blight (EB) caused by Alternaria solani. Six tomato varieties; viz. Riograndae, Roma and Basket (resistant) and T-88572, BHN-961 and BHN-1021(susceptible) were inoculated with a blend of five isolates of Alternaria solani, collected from different regions of Faisalabad District. These six varieties for mineral profiling were selected after two years screening from twenty-five varieties of tomatoes under field conditions. These varieties were sown in pots and artificial inoculation was performed to develop disease in inoculated type of tomato plants while distilled water was applied on un-inoculated type of plants. Newly infected leaves from upper, middle and lower parts of tomato plants from resistant and susceptible groups were used to prepare sample for mineral analysis at p ≤ 0.05 and variation in mineral profiling of resistant and susceptible groups of tomato plants was determined through Nested Structured Design. Significant variation was observed in inoculated (3.12, 0.48 %, 1.17, 0.14, 0.42, 0.21, 0.69 and 1.49 ppm and un-inoculated type (8.67, 1.61%, 10.45, 0.22, 1.75, 1.98, 3.09 and 3.39 ppm) while resistant group expressed 6.59, 1.19%, 8.13, 1.973, 1.69, 1.26, 1.36, 2.43 and 2.87ppm and susceptible group exhibited 5.19, 0.91%, 5.69, 1.693, 1.24, 0.91,0.83, 1.35 and 2.22 ppm with respect to NPK, Ca, Mg, Na, Zn, Iron and copper. Resistant variety, Riograndae expressed maximum amount while T-88572 exhibited minimum amount of all mineral contents. Alterations in the mineral profiling in leaves of tomato plants can be used by researchers as biochemical markers for identification and development of resistant source against early blight of tomato and for the development of ecofriendly management strategy towards A. solani.

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