scholarly journals Fusarium Consortium Populations Associated with Asparagus Crop in Spain and Their Role on Field Decline Syndrome

2020 ◽  
Vol 6 (4) ◽  
pp. 336
Author(s):  
Alexandri María Brizuela ◽  
Eduardo De la Lastra ◽  
José Ignacio Marín-Guirao ◽  
Laura Gálvez ◽  
Miguel de Cara-García ◽  
...  

Asparagus Decline Syndrome (ADS) is one of the main phytosanitary problems of asparagus crop worldwide. Diseased plants and soil samples from 41 fields from three main production areas of Spain were surveyed. Eight Fusarium species belonging to seven species complexes were identified in soils: F. oxysporum, F. proliferatum, F. redolens, F. solanisensu stricto, F. equiseti, F. culmorum, F. compactum and F. acuminatum. Fusarium oxysporum was the most prevalent species. Statistical correlation (R2 = 88%) was established between F. oxysporum inoculum density and the average temperature of the warmest month. A relationship was also established between three crop factors (average temperature, crop age and F. oxysporum inoculum density) and field disease indices. Significant differences were observed between the distribution of F. oxysporum propagules in white and green asparagus fields. Thirteen Fusarium species belonging to seven species complexes were identified from roots of diseased plants, being F. oxysporum the most prevalent. F. proliferatum, F. oxysporum and F. redolens showed pathogenicity to asparagus and were the main species associated to ADS. Fusarium oxysporum was the species with the highest genetic diversity displaying 14 sequence-based haplotypes with no geographic differentiation. This work contributes to understanding the Fusarium complex associated to ADS for developing accurate integrated disease management strategies.

2012 ◽  
Vol 102 (5) ◽  
pp. 524-530 ◽  
Author(s):  
M.C.G. Correa ◽  
J-F. Germain ◽  
T. Malausa ◽  
T. Zaviezo

AbstractMealybugs are major pests of grapevines worldwide. They cause economic losses by lowering the cosmetic value of fruits, reducing yields, transmitting viruses and resulting in the quarantine or rejection of produce in international trade. Knowledge of the species present in a vineyard is important for the adjustment of management strategies. We surveyed and accurately characterized the mealybugs infesting vineyards in one of the main production areas of Chile; 164 mealybugs were sampled from 26 vineyards in four regions of Chile and identified by DNA sequencing for two markers (cytochrome oxidase I and internal transcribed spacer 2) and morphological examination.Pseudococcus viburni(Signoret) was the most common species, followed byPseudococcus meridionalisPrado andPseudococcus cribataGonzález. Molecular variability at the COI and ITS2 loci was observed in bothP. viburniandP. cribata. A comparison of haplotypes ofP. viburniworldwide provides support for a recent hypothesis that this species is native to South America, a finding with direct consequences for management. NeitherPseudococcus longispinus(Targioni & Tozzetti) norPlanococcus ficusSignoret were found.


Mycoses ◽  
2021 ◽  
Author(s):  
Hamid Badali ◽  
Connie Cañete‐Gibas ◽  
Hoja Patterson ◽  
Carmita Sanders ◽  
Barbara Mermella ◽  
...  

2005 ◽  
Vol 77 (2) ◽  
pp. 83-92 ◽  
Author(s):  
C. Richard ◽  
J.-G. Martin ◽  
S. Pouleur

In order to know which species of Fusarium are ice nucleating and to determine the factors affecting their pathogenicity, ice nucleation activity (INA) was examined in Fusarium oxysporum, F. sporotrichioides, and F. tricinctum. Positive controls (lna+) used were F. acuminatum and F. avenaceum. The test for fungal INA was done with a simple and rapid tube nucleation assay. Twelve out of the 42 F. oxysporum isolates, and 8 out of 14 F. tricinctum isolates were lna+. No INA was detected in F sporotrichioides. In this test the threshold freezing temperature tended to increase with culture age, reaching a peak of -1°C in a few samples, which is as high as the warmest INA reported for bacteria, and higher than the INA detected in pure cultures of free-living fungi, lichen fungi, lichen algae and cyanobacteria. This is the first report of INA for F oxysporum.


Plant Disease ◽  
2021 ◽  
Author(s):  
Terry Torres-Cruz ◽  
Briana Whitaker ◽  
Robert Proctor ◽  
Kirk Broders ◽  
Imane Laraba ◽  
...  

Species within Fusarium are of global agricultural, medical, and food/feed safety concern and have been extensively characterized. However, accurate identification of species is challenging and usually requires DNA sequence data. FUSARIUM-ID (http://isolate.fusariumdb.org/) is a publicly available database designed to support the identification of Fusarium species using sequences of multiple phylogenetically informative loci, especially the highly informative ~680 bp 5' portion of the translation elongation factor 1-alpha (TEF1) gene that has been adopted as the primary barcoding locus in the genus. However, FUSARIUM-ID v.1.0 and 2.0 had several limitations, including inconsistent metadata annotation for the archived sequences and poor representation of some species complexes and marker loci. Here, we present FUSARIUM-ID v.3.0, which provides the following improvements: (i) additional and updated annotation of metadata for isolates associated with each sequence, (ii) expanded taxon representation in the TEF1 sequence database, (iii) availability of the sequence database as a downloadable file to enable local BLAST queries, and (iv) a tutorial file for users to perform local BLAST searches using either freely-available software, such as SequenceServer, BLAST+ executable in the command line, and Galaxy, or the proprietary Geneious software. FUSARIUM-ID will be updated on a regular basis by archiving sequences of TEF1 and other loci from newly identified species and greater in-depth sampling of currently recognized species.


Plant Disease ◽  
2019 ◽  
Vol 103 (4) ◽  
pp. 705-710 ◽  
Author(s):  
Martha H. Froelich ◽  
Guido Schnabel

A survey of fungal pathogens causing twig blight on commercial peach trees was conducted in South Carolina in the fall of 2016. Shoots with cankers, pycnidia, and dieback were collected from six locations around the state. Isolates obtained from these samples were identified as Botryosphaeria obtusa, Phomopsis amygdali, Leucostoma persoonii, and Cytospora sp., based on colony morphology, conidia size and shape, and ribosomal DNA sequence analysis. L. persoonii was the most prevalent species and was isolated in five of the six locations, followed by P. amygdali and B. obtusa. The sensitivity of representative isolates of B. obtusa, P. amygdali, and L. persoonii to fungicides of different FRAC codes was evaluated. All species tested were sensitive to thiophanate-methyl (FRAC 1) and pyraclostrobin and azoxystrobin (both FRAC 11), whereas all species were resistant to boscalid and fluopyram (both FRAC 7). P. amygdali and B. obtusa were sensitive to difenoconazole and propiconazole (both FRAC 3), whereas L. persoonii was moderately resistant. L. persoonii was the most virulent species based on expansion of mycelium in the cambium layer of 2-year-old, detached twig pieces. Bacterial spot (BS)-sensitive cultivar ‘O’Henry’ was most susceptible to B. obtusa compared with BS-sensitive ‘Summerprince’, brown rot (BR)-resistant ‘Contender’, and BR-sensitive ‘Coronet’ but was least susceptible to L. persoonii. Coronet was most susceptible to L. persoonii. There were no significant differences between susceptibility of the cultivars to P. amygdali. This study established that L. persoonii is currently the most frequent twig blight pathogen in South Carolina, perhaps owing to its superior fitness. Some fungicides were effective in controlling all twig blight pathogens and may therefore be useful for chemical management strategies. Our study also provides the first evidence that the genetic basis of resistance to BS and BR in peach trees is not necessarily linked to tolerance to wood pathogens.


2021 ◽  
Vol 60 (1) ◽  
pp. 51-62
Author(s):  
Samia LAALA ◽  
Sophie CESBRON ◽  
Mohamed KERKOUD ◽  
Franco VALENTINI ◽  
Zouaoui BOUZNAD ◽  
...  

Xanthomonas campestris pv. campestris (Xcc) causes the black rot of cruciferous plants. This seed-borne bacterium is considered as the most destructive disease to cruciferous crops. Although sources of contamination are various, seeds are the main source of transmission. Typical symptoms of black rot were first observed in 2011 on cabbage and cauliflower fields in the main production areas of Algeria. Leaf samples displaying typical symptoms were collected during 2011 to 2014, and 170 strains were isolated from 45 commercial fields. Xcc isolates were very homogeneous in morphological, physiological and biochemical characteristics similar to reference strains, and gave positive pathogenicity and molecular test results (multiplex PCR with specific primers). This is the first record of Xcc in Algeria. Genetic diversity within the isolates was assessed in comparison with strains isolated elsewhere. A multilocus sequence analysis based on two housekeeping genes (gyrB and rpoD) was carried out on 77 strains representative isolates. The isolates grouped into 20 haplotypes defined with 68 polymorphic sites. The phylogenetic tree obtained showed that Xcc is in two groups, and all Algerian strains clustered in group 1 in three subgroups. No relationships were detected between haplotypes and the origins of the seed lots, the varieties of host cabbage, the years of isolation and agroclimatic regions.


2022 ◽  
Vol 10 (1) ◽  
pp. 126
Author(s):  
Antonio Lozano-León ◽  
Carlos García-Omil ◽  
Rafael R. Rodríguez-Souto ◽  
Alexandre Lamas ◽  
Alejandro Garrido-Maestu

Salmonella spp. and antimicrobial resistant microorganisms are two of the most important health issues worldwide. In the present study, strains naturally isolated from mussels harvested in Galicia (one of the main production areas in the world), were genetically characterized attending to the presence of virulence and antimicrobial resistance genes. Additionally, the antimicrobial profile was also determined phenotypically. Strains presenting several virulence genes were isolated but lacked all the antimicrobial resistance genes analyzed. The fact that some of these strains presented multidrug resistance, highlighted the possibility of bearing different genes than those analyzed, or resistance based on completely different mechanisms. The current study highlights the importance of constant surveillance in order to improve the safety of foods.


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1955
Author(s):  
Anysia Hedy Ujat ◽  
Ganesan Vadamalai ◽  
Yukako Hattori ◽  
Chiharu Nakashima ◽  
Clement Kiing Fook Wong ◽  
...  

The re-emergence of the Fusarium wilt caused by Fusarium odoratissimum (F. odoratissimum) causes global banana production loss. Thirty-eight isolates of Fusarium species (Fusarium spp.) were examined for morphological characteristics on different media, showing the typical Fusarium spp. The phylogenetic trees of Fusarium isolates were generated using the sequences of histone gene (H3) and translation elongation factor gene (TEF-1α). Specific primers were used to confirm the presence of F. odoratissimum. The phylogenetic trees showed the rich diversity of the genus Fusarium related to Fusarium wilt, which consists of F. odoratissimum, Fusarium grosmichelii, Fusarium sacchari, and an unknown species of the Fusarium oxysporum species complex. By using Foc-TR4 specific primers, 27 isolates were confirmed as F. odoratissimum. A pathogenicity test was conducted for 30 days on five different local cultivars including, Musa acuminata (AAA, AA) and Musa paradisiaca (AAB, ABB). Although foliar symptoms showed different severity of those disease progression, vascular symptoms of the inoculated plantlet showed that infection was uniformly severe. Therefore, it can be concluded that the Fusarium oxysporum species complex related to Fusarium wilt of banana in Malaysia is rich in diversity, and F. odoratissimum has pathogenicity to local banana cultivars in Malaysia regardless of the genotype of the banana plants.


2019 ◽  
Author(s):  
Gláucia Mara Moreira ◽  
Camila Primieri Nicolli ◽  
Larissa Bitencourt Gomes ◽  
Claudigo Ogoshi ◽  
Klaus K. Scheuermann ◽  
...  

Ninety three samples of rice were obtained from research and commercial plots at eight rice-producing regions of Brazil and analyzed for the presence of Fusarium species and 14 mycotoxins. A total of 352 isolates belonging to Fusarium genus were obtained from 85 % of the samples. These were assigned to four species complexes (SC) based on morphological identification. The most frequent SC detected was F. incarnatum-equiseti (FIESC, 32.4 %) followed by F. fujikuroi (FFSC, 26.1 %), F. graminearum (FGSC, 24.7 %) and F. chlamydosporum (FCSC, 16.8 %). FGSC was limited geographically and dominant in the southern subtropical production regions while the others occurred in all regions, particularly FIESC, the most widespread among them. The samples were individually contaminated with three to eight mycotoxins. The most common mycotoxins detected were zearalenone (ZEA), beauvericin, and acetylated forms of deoxynivalenol (AcDON). Other toxins included enniatins, T-2, HT-2, DON, neosolaniol and moniliformin. The concentration levels were all below the Brazilian promulgated limits established only for DON (< 750 ppb), and ZEA (< 100 ppb) with one exception for the latter. Most toxins were found in both the husk and flour fractions, but AcDON tended to concentrate more in the husk. Our survey extends considerable our knowledge of the Fusarium complexes infecting rice and provides an update on the status of rice mycotoxin contamination at the country level, which can be considered generally safe. However, attention should be paid to the widespread contamination of beauvericin.


2018 ◽  
Vol 156 (3) ◽  
pp. 396-407 ◽  
Author(s):  
Gaia Vaglio Laurin ◽  
Claudio Belli ◽  
Roberto Bianconi ◽  
Pietro Laranci ◽  
Dario Papale

AbstractTimely crop information, i.e. well before harvesting time and at first stages of crop development, can benefit farmers and producer organizations. The current case study documents the procedure to deliver early data on planted tomato to users, showing the potential of Sentinel 2 (S2) to map tomato at the very beginning of the crop season, which is a challenging task. Using satellite data, integrated with ground and aerial data, an initial estimate of area planted with tomato and early tomato maps were generated in seven main production areas in Italy. Estimates of the amount of area planted with tomato provided similar results either when derived from field surveys or from remote-sensing-based classification. Tomato early maps showed a producer accuracy >80% in seven cases out of nine, and a user accuracy >80% in five cases out of nine, with differences attributed to the varying agricultural characteristics and environmental heterogeneity of the study areas. The additional use of aerial data improved producer accuracy moderately. The ability to identify abrupt growth changes, such as those caused by natural hazards, was also analysed: S2 detected significant changes in tomato growth between a hailstorm-affected area and a control area. The study suggests that S2, with enhanced spectral capabilities and open data policy, represents very valuable data, allowing crop monitoring at an early development stage.


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