Potential distribution and ecological niches of four butt-rot pathogenic fungi in Northeast China

2019 ◽  
Vol 27 (8) ◽  
pp. 873-879
Author(s):  
Yuan Hai-Sheng ◽  
Wei Yulian ◽  
Zhou Liwei ◽  
Qin Wenmin ◽  
Cui Baokai ◽  
...  
Keyword(s):  
Northeast China ◽  
Potential Distribution ◽  
Pathogenic Fungi ◽  
Ecological Niches ◽  
Butt Rot

scholarly journals Ecological niche overlap among species of the genus Zaluzania (Asteraceae) from the dry regions of Mexico

2020 ◽  
Vol 153 (3) ◽  
pp. 337-347
Author(s):  
Mario Ernesto Suárez-Mota ◽  
José Luis Villaseñor
Keyword(s):  
Ecological Niche ◽  
Potential Distribution ◽  
Area Under The Curve ◽  
Niche Overlap ◽  
Ecological Niches ◽  
Niche Conservatism ◽  
Distribution Models ◽  
Closely Related Species ◽  
Environmental Pressures ◽  
Fundamental Niche

Background and aims – The hypothesis of ecological niche conservatism postulates that closely related species share ecologically similar environments; that is, they tend to maintain the characteristics of their fundamental niche over time. The objective of this study is to evaluate the similarity and equivalence of the ecological niches among species of the genus Zaluzania (Asteraceae), characteristic of the Mexican arid and semi-arid regions, to infer their potential niche conservatism. Methods – Based on critically reviewed herbarium occurrence data, potential distribution models for eight species of Zaluzania were generated using the Maxent algorithm. The overlap between potential distribution areas was then evaluated using equivalence and ecological niche parameters implemented in the ENMTools software; for this we quantified the degree of overlap and similarity between the niches using the equivalence (D) and similarity (I) parameters.Key results – The resulting models show that species display areas of high suitability along the Mexican dry regions, as well as overlapping heterogeneous values. All models showed high AUC (Area Under the Curve) values (> 0.8). The D and I values between each pair of species showed low values of overlap.Conclusions – Each species of the genus shows a fundamental niche distinct from their sister species. The genus thus offers an example of niche divergence among species, with each one adapting to different environmental pressures. Our results do not support the hypothesis of niche conservatism in the genus, suggesting that the species evolved in divergent environments.

scholarly journals Insect-Specific Polyketide Synthases (PKSs), Potential PKS-Nonribosomal Peptide Synthetase Hybrids, and Novel PKS Clades in Tropical Fungi

2009 ◽  
Vol 75 (11) ◽  
pp. 3721-3732 ◽  
Author(s):  
Alongkorn Amnuaykanjanasin ◽  
Suranat Phonghanpot ◽  
Nattapong Sengpanich ◽  
Supapon Cheevadhanarak ◽  
Morakot Tanticharoen
Keyword(s):  
Polyketide Synthase ◽  
Pathogenic Fungi ◽  
Nonribosomal Peptide Synthetase ◽  
Bootstrap Support ◽  
Future Research ◽  
Ecological Niches ◽  
Tropical Fungi ◽  
Degenerate Primers ◽  
Nonribosomal Peptide ◽  
Peptide Synthetase

ABSTRACT Polyketides draw much attention because of their potential use in pharmaceutical and biotechnological applications. This study identifies an abundant pool of polyketide synthase (PKS) genes from local isolates of tropical fungi found in Thailand in three different ecological niches: insect pathogens, marine inhabitants, and lichen mutualists. We detected 149 PKS genes from 48 fungi using PCR with PKS-specific degenerate primers. We identified and classified 283 additional PKS genes from 13 fungal genomes. Phylogenetic analysis of all these PKS sequences the comprising ketosynthase (KS) conserved region and the KS-acyltransferase interdomain region yielded results very similar to those for phylogenies of the KS domain and suggested a number of remarkable points. (i) Twelve PKS genes amplified from 12 different insect-pathogenic fungi form a tight cluster, although along with two PKS genes extracted from genomes of Aspergillus niger and Aspergillus terreus, in reducing clade III. Some of these insect-specific fungal PKSs are nearly identical. (ii) We identified 38 new PKS-nonribosomal peptide synthetase hybrid genes in reducing clade II. (iii) Four distinct clades were discovered with more than 75% bootstrap support. We propose to designate the novel clade D1 with 100% bootstrap support “reducing clade V.” The newly cloned PKS genes from these tropical fungi should provide useful and diverse genetic resources for future research on the characterization of polyketide compounds synthesized by these enzymes.

scholarly journals Factores biogeográficos y cambios de uso del suelo (2009-2013) en el nicho de "Trogon elegans ambiguus" y "Euptilotis neoxenus" en Chihuahua, México

2018 ◽  
Vol 44 (2) ◽  
pp. 763
Author(s):  
M.E. Torres-Olave ◽  
L.C. Bravo-Peña ◽  
L.C. Alatorre-Cejudo ◽  
M.I. Uc-Campos ◽  
M.O. González-León
Keyword(s):  
Land Use ◽  
Vegetation Dynamics ◽  
Ecological Niche ◽  
Potential Distribution ◽  
Plant Cover ◽  
Land Use Changes ◽  
Hardwood Forests ◽  
Ecological Niches ◽  
Niche Modelling ◽  
Current State

Few studies have addressed the current state of the Trogon elegans ambiguus and Euptilotis neoxenus ecological niches, as well as the vegetation dynamics and land use changes where these birds live. This work estimates the potential distribution of Trogon elegans ambiguus and Euptilotis neoxenus in Chihuahua and studies the land use changes in two time periods (2009 and 2015). The MaxEnt software was used to model the ecological niches in Chihuahua, Mexico. The maps of changes in land use and plant cover were reclassified and the classes were homogenized. A crosstab analysis was used to compare correspondence matrices. The results indicate that Trogon elegans ambiguus and Euptilotis neoxenus underwent a niche loss in conifer and hardwood forests, which became farmland or pasture-bushes. Ecological niche modelling is a useful tool to identify suitable areas for species with NOM-059-SEMARNAT-2010 status. In the case of Trogon elegans ambiguus, land use changes mainly affect the municipalities of Temosachi and Madera.

scholarly journals Evaluation of Antifungal Activity of Antagonistic Bacteria against Butt Rot Disease Pathogen of Pineapple

2017 ◽  
Vol 15 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Mat Nawi NURNADIRAH ◽  
Kartini Che Mohd Ramli NENI ◽  
Mohd Yunus Nor YUZIAH
Keyword(s):  
Antifungal Activity ◽  
Pathogenic Fungi ◽  
Culture Method ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Butt Rot ◽  
Additional Control ◽  
Inhibitory Potential ◽  
Rot Disease

Butt rot disease, caused by Thielaviopsis paradoxa (De Seynes) Hohn., is one of the major diseases in pineapple cultivation in Malaysia. The objectives of this study were to evaluate the antifungal effect of antagonist bacteria against T. paradoxa, a causal agent of butt rot disease, and to observe the mechanism of antifungal activity of tested antagonist bacteria microscopically. In this study, in vitro antifungal potential of 5 antagonist bacteria, namely B1, B2, B3, B4, and B5, were isolated from infected and non-infected soil samples and evaluated using dual culture method against T. paradoxa. The mechanisms of antifungal activities of antagonist bacteria against the pathogen were microscopically observed. All of the bacteria showed inhibitory effects against the pathogenic fungi. B1 bacteria showed the highest inhibitory potential, with 73 % inhibition, followed by B2, B3, B4, and B5, with 71, 57, 56, and 48 % of inhibition compared to control, respectively. The results also showed that B2, B3, and B4 bacteria exhibited positive inhibition towards the pathogen, with more than 50 % percentage inhibition. The development of a new product for use as a biocontrol agent, used as an additional control or used in combination with existing ones, may reduce dependency on chemical control and increase antagonistic activity efficiency.

scholarly journals Shifted distribution baselines: neglecting long-term biodiversity records risks overlooking potentially suitable habitat for conservation management

2019 ◽  
Vol 374 (1788) ◽  
pp. 20190215 ◽  
Author(s):  
Sophie Monsarrat ◽  
Peter Novellie ◽  
Ian Rushworth ◽  
Graham Kerley
Keyword(s):  
Habitat Suitability ◽  
Potential Distribution ◽  
Habitat Preferences ◽  
Ecological Niches ◽  
Suitable Habitat ◽  
Ecological Data ◽  
Distribution Models ◽  
Mammal Species ◽  
Occurrence Records

Setting appropriate conservation measures to halt the loss of biodiversity requires a good understanding of species' habitat requirements and potential distribution. Recent (past few decades) ecological data are typically used to estimate and understand species’ ecological niches. However, historical local extinctions may have truncated species–environment relationships, resulting in a biased perception of species' habitat preferences. This may result in incorrect assessments of the area potentially available for their conservation. Incorporating long-term (centuries-old) occurrence records with recent records may provide better information on species–environment relationships and improve the modelling and understanding of habitat suitability. We test whether neglecting long-term occurrence records leads to an underestimation of species’ historical niche and potential distribution and identify which species are more vulnerable to this effect. We compare outputs of species distribution models and niche hypervolumes built using recent records only with those built using both recent and long-term (post-1500) records, for a set of 34 large mammal species in South Africa. We find that, while using recent records only is adequate for some species, adding historical records in the analyses impacts estimates of the niche and habitat suitability for 12 species (34%) in our dataset, and that this effect is significantly higher for carnivores. These results show that neglecting long-term biodiversity records in spatial analyses risks misunderstanding, and generally underestimating, species' niches, which in turn may lead to ill-informed management decisions, with significant implications for the effectiveness of conservation efforts. This article is part of a discussion meeting issue ‘The past is a foreign country: how much can the fossil record actually inform conservation?’

scholarly journals Potential distribution and geographic characteristics of wild populations of Vanilla planifolia (Orchidaceae) Oaxaca, Mexico

2016 ◽  
Vol 64 (1) ◽  
pp. 235
Author(s):  
Jesús Hernandez-Ruiz ◽  
B. Edgar Herrera-Cabrera ◽  
Adriana Delgado-Alvarado ◽  
Víctor M. Salazar-Rojas ◽  
Ángel Bustamante-Gonzalez ◽  
...  
Keyword(s):  
Potential Distribution ◽  
The State ◽  
Systematic Search ◽  
Distribution Area ◽  
Ecological Niches ◽  
Moisture Regime ◽  
Type I ◽  
Vanilla Planifolia ◽  
Evergreen Forests ◽  
Bioclimatic Variables

Wild specimens of Vanilla planifolia represent a vital part of this resource primary gene pool, and some plants have only been reported in Oaxaca, Mexico. For this reason, we studied its geographical distribution within the state, to locate and describe the ecological characteristics of the areas where they have been found, in order to identify potential areas of establishment. The method comprised four stages: 1) the creation of a database with herbarium records, 2) the construction of the potential distribution based on historical herbarium records for the species, using the model of maximum entropy (MaxEnt) and 22 bioclimatic variables as predictors; 3) an in situ systematic search of individuals, based on herbarium records and areas of potential distribution in 24 municipalities, to determine the habitat current situation and distribution; 4) the description of the environmental factors of potential ecological niches generated by MaxEnt. A review of herbarium collections revealed a total of 18 records of V. planifolia between 1939 and 1998. The systematic search located 28 plants distributed in 12 sites in 95 364 Km2. The most important variables that determined the model of vanilla potential distribution were: precipitation in the rainy season (61.9 %), soil moisture regime (23.4 %) and precipitation during the four months of highest rainfall (8.1 %). The species potential habitat was found to be distributed in four zones: wet tropics of the Gulf of Mexico, humid temperate, humid tropical, and humid temperate in the Pacific. Precipitation oscillated within the annual ranges of 2 500 to 4 000 mm, with summer rains, and winter precipitation as 5 to 10 % of the total. The moisture regime and predominating climate were udic type I (330 to 365 days of moisture) and hot humid (Am/A(C) m). The plants were located at altitudes of 200 to 1 190 masl, on rough hillsides that generally make up the foothills of mountain systems, with altitudes of 1 300 to 2 500 masl. In natural conditions, distribution of the species is not limited to high evergreen forests, since it was also found in mountain mesophyll and tropical evergreen forests. The location of new specimens of V. planifolia in its wild condition reduces the potential distribution area by 66 %. This area is fragmented into three geographically separated areas. Habitat reduction was due to the increased number of located plants that define the environmental conditions into a more accurate level. Conservation actions can thus be designed and implemented, focusing on more specific areas within the state of Oaxaca, Mexico.

Potential distribution and conservation priority areas of five species in Northeast China

2019 ◽  
Vol 39 (3) ◽  
Author(s):  
杨蕾 YANG Lei ◽  
杨立 YANG Li ◽  
李婧昕 LI Jingxin ◽  
张超 ZHANG Chao ◽  
霍兆敏 HUO Zhaomin ◽  
...  
Keyword(s):  
Northeast China ◽  
Potential Distribution ◽  
Conservation Priority ◽  
Priority Areas

scholarly journals Ecological niche overlap among species of the genus Zaluzania (Asteraceae) from the dry regions of Mexico

2020 ◽  
Vol 153 (3) ◽  
pp. 337-347
Author(s):  
Mario Ernesto Suárez-Mota ◽  
José Luis Villaseñor
Keyword(s):  
Ecological Niche ◽  
Potential Distribution ◽  
Area Under The Curve ◽  
Niche Overlap ◽  
Ecological Niches ◽  
Niche Conservatism ◽  
Distribution Models ◽  
Closely Related Species ◽  
Environmental Pressures ◽  
Fundamental Niche

Background and aims – The hypothesis of ecological niche conservatism postulates that closely related species share ecologically similar environments; that is, they tend to maintain the characteristics of their fundamental niche over time. The objective of this study is to evaluate the similarity and equivalence of the ecological niches among species of the genus Zaluzania (Asteraceae), characteristic of the Mexican arid and semi-arid regions, to infer their potential niche conservatism. Methods – Based on critically reviewed herbarium occurrence data, potential distribution models for eight species of Zaluzania were generated using the Maxent algorithm. The overlap between potential distribution areas was then evaluated using equivalence and ecological niche parameters implemented in the ENMTools software; for this we quantified the degree of overlap and similarity between the niches using the equivalence (D) and similarity (I) parameters.Key results – The resulting models show that species display areas of high suitability along the Mexican dry regions, as well as overlapping heterogeneous values. All models showed high AUC (Area Under the Curve) values (> 0.8). The D and I values between each pair of species showed low values of overlap.Conclusions – Each species of the genus shows a fundamental niche distinct from their sister species. The genus thus offers an example of niche divergence among species, with each one adapting to different environmental pressures. Our results do not support the hypothesis of niche conservatism in the genus, suggesting that the species evolved in divergent environments.

The effects of surface absorbed monolayer microdiffraction patterns

1988 ◽  
Vol 46 ◽  
pp. 680-681
Author(s):  
M. Pan ◽  
J.M. Cowley
Keyword(s):  
Surface Potential ◽  
Electron Probe ◽  
Potential Distribution ◽  
Crystal Surface ◽  
Normal Direction ◽  
Surface Image ◽  
Extended Surface ◽  
Gas Molecules ◽  
Surface Nature ◽  
Electron Microdiffraction

Electron microdiffraction patterns, obtained when a small electron probe with diameter of 10-15 Å is directed to run parallel to and outside a flat crystal surface, are sensitive to the surface nature of the crystals. Dynamical diffraction calculations have shown that most of the experimental observations for a flat (100) face of a MgO crystal, such as the streaking of the central spot in the surface normal direction and (100)-type forbidden reflections etc., could be explained satisfactorily by assuming a modified image potential field outside the crystal surface. However the origin of this extended surface potential remains uncertain. A theoretical analysis by Howie et al suggests that the surface image potential should have a form different from above-mentioned image potential and also be smaller by several orders of magnitude. Nevertheless the surface potential distribution may in practice be modified in various ways, such as by the adsorption of a monolayer of gas molecules.

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