scholarly journals Visualization of Three Sclerotiniaceae Species Pathogenic on Onion Reveals Distinct Biology and Infection Strategies

2021 ◽  
Vol 22 (4) ◽  
pp. 1865
Author(s):  
Maikel B. F. Steentjes ◽  
Sebastian Tonn ◽  
Hilde Coolman ◽  
Sander Langebeeke ◽  
Olga E. Scholten ◽  
...  
Keyword(s):  
Fungal Species ◽  
White Rot ◽  
Sclerotium Cepivorum ◽  
Prolonged Contact ◽  
The Family ◽  
Infection Mechanisms ◽  
Infection Biology ◽  
Onion Epidermal Cells ◽  
Close Relatedness ◽  
Infection Cushions

Botrytis squamosa, Botrytis aclada, and Sclerotium cepivorum are three fungal species of the family Sclerotiniaceae that are pathogenic on onion. Despite their close relatedness, these fungi cause very distinct diseases, respectively called leaf blight, neck rot, and white rot, which pose serious threats to onion cultivation. The infection biology of neck rot and white rot in particular is poorly understood. In this study, we used GFP-expressing transformants of all three fungi to visualize the early phases of infection. B. squamosa entered onion leaves by growing either through stomata or into anticlinal walls of onion epidermal cells. B. aclada, known to cause post-harvest rot and spoilage of onion bulbs, did not penetrate the leaf surface but instead formed superficial colonies which produced new conidia. S. cepivorum entered onion roots via infection cushions and appressorium-like structures. In the non-host tomato, S. cepivorum also produced appressorium-like structures and infection cushions, but upon prolonged contact with the non-host the infection structures died. With this study, we have gained understanding in the infection biology and strategy of each of these onion pathogens. Moreover, by comparing the infection mechanisms we were able to increase insight into how these closely related fungi can cause such different diseases.

scholarly journals Biological control of garlic (Allium) white rot disease using antagonistic fungi-based bioformulations

2015 ◽  
Vol 55 (2) ◽  
pp. 136-141 ◽  
Author(s):  
Razak Mahdizadehnaraghi ◽  
Asghar Heydari ◽  
Hamid Reza Zamanizadeh ◽  
Saeed Rezaee ◽  
Jafar Nikan
Keyword(s):  
Rice Bran ◽  
Control Method ◽  
Control Measure ◽  
Fungal Species ◽  
White Rot ◽  
Sclerotium Cepivorum ◽  
Common Control ◽  
Talaromyces Flavus ◽  
Rot Disease ◽  
Almost All

Abstract White rot disease caused by Sclerotium cepivorum is a major yield reducing fungal disease of garlic found throughout the world, including Iran. The use of chemical fungicides is the most common control method for the disease at the present time. This control measure is costly, contaminates the environment, and harms non-target organisms. Moreover, since the pathogen is soil-borne, chemical control strategy is not quite effective against the disease. In this study, we tried to develop and prepare some new bioformulations based on three antagonistic fungal species: Trichoderma harzianum, T. asperellum, and Talaromyces flavus. Six isolates of the above-mentioned fungi were used along with the organic and inorganic carriers, rice bran and talc, to develop twelve new bioformulations. The effectiveness of the bioformulations were then evaluated in the control of garlic white rot disease in the greenhouse conditions in comparison with the healthy control, infected control, and the commonly used fungicide Carbendazim. The design of the experiment was completely randomised. There were 15 treatments each, with four replicates. The results of the greenhouse experiments indicated that almost all the developed bioformulations resulted in significant reductions (34.50 to 64.50%) in the incidence of white rot disease. In general, bioformulations which contained the organic carrier (rice bran) performed more effectively than those that contained the inorganic carrier (talc). Bioformulations which contained an organic carrier (rice bran) were as effective as the fungicide Carbendazim.

The mycobiome of the oral cavity in healthy dogs and dogs with periodontal disease

2022 ◽  
pp. 1-8
Author(s):  
Brook A. Niemiec ◽  
Jerzy Gawor ◽  
Shuiquan Tang ◽  
Aishani Prem ◽  
Janina A. Krumbeck
Keyword(s):  
Oral Cavity ◽  
Periodontal Disease ◽  
Dna Sequencing ◽  
Fungal Species ◽  
Next Generation ◽  
Data Set ◽  
Next Generation Dna Sequencing ◽  
Sequencing Platform ◽  
The Family ◽  
Healthy Dogs

Abstract OBJECTIVE To investigate the mycobiome of the oral cavity in healthy dogs and dogs with various stages of periodontal disease. ANIMALS 51 dogs without periodontal disease (n = 12) or with mild (10), moderate (19), or severe (10) periodontal disease. PROCEDURES The whole maxillary arcade of each dog was sampled with a sterile swab, and swabs were submitted for next-generation DNA sequencing targeting the internal transcribed spacer 2 region with a commercial sequencing platform. RESULTS Fungi were detected in all samples, with a total of 320 fungal species from 135 families detected in the data set. No single fungal species was found in all samples. The 3 most frequently found fungal species were Cladosporium sp (46/51 samples), Malassezia restricta (44/51 samples), and Malassezia arunalokei (36/51 samples). Certain fungi, specifically those of the family Didymellaceae, the family Irpicaceae, and the order Pleosporales, were significantly associated with different stages of periodontitis. Mycobial analysis indicated that Cladosporium sp could be considered part of the core oral cavity mycobiome. CONCLUSIONS AND CLINICAL RELEVANCE Results highlighted that fungi are present in the oral cavity of dogs and are characterized by substantial species diversity, with different fungal communities associated with various stages of periodontal disease. The next-generation DNA sequencing used in the present study revealed substantially more species of fungi than previous culture-based studies.

scholarly journals PENGARUH KONSORSIUM AGENS HAYATI DAN JARAK TANAM TERHADAP KEJADIAN PENYAKIT BUSUK PUTIH (Sclerotium cepivorum Berk.) PADA BAWANG DAUN Influence of The Consortium of Biological Agents and Spacing to White Rot Disease (Sclerotium cepivorum Berk.) of Scallio

AgriPeat ◽  
2019 ◽  
Vol 20 (02) ◽  
pp. 92-98
Author(s):  
Admin Journal
Keyword(s):  
Block Design ◽  
Peat Soil ◽  
Nutrient Content ◽  
Biological Agents ◽  
White Rot ◽  
Plant Weight ◽  
Sclerotium Cepivorum ◽  
Trichoderma Sp ◽  
Rot Disease ◽  
Aspergillus Sp

ABSTRACTThis study aims to determine effective management patterns to control Sclerotium rot and to improvepeat soil fertility with the application of the Trichoderma sp + Aspergillus sp consortium.as biologicalagents and P solvents, combined with spacing arrangements in the cultivation of scallion in peatlands.The study used a factorial randomized block design consisting of two factors with four replications.Factor I Application of biological agents consists of: A0 = No biological agents; A1 = Consortium ofTrichoderma sp. + Aspergillus sp; Factor II Plant spacing, consisting of J1 = 20x25 cm; J2 = 25x25cm and J3 = 30x25 cm. The results showed that the interaction treatment of Trichoderma sp. +Aspergillus sp. and spacing of 25x25 cm effectively suppresses the incidence of white rot disease(Sclerotium cepivorum Berk) up to 34.02%, while at a spacing of 20x25 cm with the application ofTrichoderma sp. + Aspergillus sp. produced the highest fresh plant weight of 8.80 kg plot-1 or 24.44tons hectares-1. Increasing the number of leaves is only influenced by a single factor of biologicalagents (23.29%) and spacing of 25x25 cm (19.7%). Application of Trichoderma sp. + Aspergillus sp.can increase the nutrient content of N, P (total and available), K and peat soil organic matter.Consortium of biological agents Trichoderma sp. and Aspergillus sp. indigenous have the potential tobe developed as biological agents and biofertilizers, with optimum spacing can be applied to themanagement of scallion cultivation in peatlands.Key words: Sclerotium cepivorum Berk, scallion, Trichoderma sp. and Aspergillus sp., spacing

scholarly journals Flavor Precursor [S-alk(en)yl-L-cysteine sulfoxide] Concentration and Composition in Onion Plant Organs and Predictability of Field White Rot Reaction of Onions

2005 ◽  
Vol 130 (2) ◽  
pp. 196-202 ◽  
Author(s):  
Marilyn H.Y. Hovius ◽  
Irwin L. Goldman ◽  
Kirk L. Parkin
Keyword(s):  
High Performance ◽  
Disease Incidence ◽  
Field Trials ◽  
White Rot ◽  
Individual Plant ◽  
Onion Plant ◽  
Plant Organs ◽  
Breeding Lines ◽  
Sclerotium Cepivorum ◽  
Cysteine Sulfoxide

Breeders have found field screening for white rot (Sclerotium cepivorum Berk.) resistance in onion (Allium cepa L.) to be unreliable since consistently moderate to high disease levels that significantly differentiate cultivars do not occur over field sites and years. The objective was to determine if differences in onion white rot resistance levels were associated with differing S-alk(en)yl-l-cysteine sulfoxide (ACSO) levels. A collection of onion breeding lines and hybrids were evaluated in field trials at six sites in 1999-2001. High performance liquid chromatography was used to analyze ACSOs in onion plant organs. Four main cysteine-sulfoxides exist in Allium L. species: methyl (MCSO), 2-propenyl (2-PeCSO), 1-propenyl (1-PeCSO), and propyl (PCSO). 1-PeCSO was predominant in onion leaves, bulbs, and roots. 2-PeCSO was found in trace amounts in onion leaves and roots. There was significantly more 2-PeCSO and total ACSO (roots only) and 1-PeCSO (roots and bulbs) in accessions that were more susceptible to white rot in the field trials. This is the first report of significant differences in ACSO contents among white rot susceptible and resistant onions. A covariance analysis was used to determine if the ACSO levels that significantly distinguished among accessions could predict field onion white rot reaction. 1-PeCSO from both roots and bulbs was the best predictor of field disease incidence in field sites that had low, moderate, and high disease levels. Although the ACSO concentrations were not assessed on an individual plant basis, breeders may be able to screen onions for resistance to S. cepivorum by comparing onion root or bulb 1-PeCSO levels based on the results from this research. White rot incidence in the field should be higher in those plants whose roots and bulbs have the highest levels of 1-PeCSO.

scholarly journals Stachybotriaceae on Cucurbits Demystified: Genetic Diversity and Pathogenicity of Ink Spot Pathogens

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2242-2251
Author(s):  
Gabriel Rennberger ◽  
Anthony P. Keinath
Keyword(s):  
South Carolina ◽  
Leaf Spot ◽  
Sequence Data ◽  
Spatial Scales ◽  
Fungal Species ◽  
Vegetable Crops ◽  
Tomato Plants ◽  
Predominant Species ◽  
The Family ◽  
The Common

Recently, the incidence of Myrothecium leaf spot, a foliar disease of watermelon, has increased in South Carolina. However, the identity of the fungal species responsible for outbreaks of this disease has not been determined. Sequence data from four partial gene regions were used to conduct Bayesian inference in order to identify 95 isolates of Stachybotriaceae. Isolates were collected in South Carolina between July 2015 and May 2018. In total, six species of Stachybotriaceae were identified on watermelon and two other cucurbits: Albifimbria verrucaria, Gregatothecium humicola, Paramyrothecium foliicola, P. humicola, Xenomyrothecium tongaense, and Xepicula leucotricha. Two species, G. humicola and P. foliicola, were the predominant species found. Within these two species, genetic differences within small spatial scales were detected. Five species (all except Xenomyrothecium tongaense) were tested in experiments to determine their pathogenicity and relative virulence on three hosts grown in rotation in South Carolina. Southern pea plants were less susceptible than watermelon and tomato plants, which were equally susceptible. This constitutes the first reliable report of pathogenicity of any of the five tested species of Stachybotriaceae on these three vegetable crops. Another important finding was that none of the isolates were identified as P. roridum, the species considered to be the only causal agent of Myrothecium leaf spot on cucurbits. We propose the common name “ink spot” for the foliar phase of diseases caused by genera within the family Stachybotriaceae. This name is descriptive and likely to be accepted by growers. To prevent further loss incurred by ink spot, watermelon and tomato crops should be monitored for this disease.

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