Method for estimating inoculum of the soilborne fungal pathogen Verticillium dahliae in Australian cotton soils

2021 ◽  
Vol 72 (2) ◽  
pp. 146
Author(s):  
S. Young ◽  
K. Kirkby ◽  
S. Roser ◽  
S. Harden
Keyword(s):  
Verticillium Dahliae ◽  
Fungal Pathogen ◽  
Soil Sampling ◽  
Field Soil ◽  
Sampling Protocol ◽  
Selective Media ◽  
Plating Method ◽  
Disease Pressure ◽  
The Vertical Distribution ◽  
The Ideal

The ability to quantify inoculum levels of the soilborne fungal pathogen Verticillium dahliae in field soil is essential for understanding potential disease pressure of Verticillium wilt in cotton and for making informed management decisions. Several semi-selective media and techniques for pathogen isolation have been developed for determining the inoculum levels of V. dahliae present in soil. The objective of this study was to gather data on soil plating techniques, media, sampling depths, and times of sampling for the detection and quantification of V. dahliae in field soils, in order to develop a V. dahliae isolation protocol for Australian cotton-growing soils. Two soil plating techniques (dilution plating or ‘wet plating’, and direct spreading by hand or ‘dry plating’) on four semi-selective media (Sorenson’s NP-10, potato dextrose agar, and acidified versions of each) were compared for their efficacy in quantifying soil inoculum as germinated microsclerotia propagules per gram soil. Soil was sampled from three depths to examine the vertical distribution of the fungus and so determine the ideal sampling depth. Field soil sampling was conducted pre-planting and post-harvest to examine differences in inoculum with sampling time. Based on the results of this study, a soil sampling protocol has been developed for Australian cotton farms that includes sampling soil before planting, at a depth of 2–24 cm, and using the direct dry plating method on Sorenson’s NP-10 media.

Pure Ni and Pd-Ni Alloy Membranes Prepared by Electroless Plating for Hydrogen Separation

2011 ◽  
Vol 179-180 ◽  
pp. 1309-1313 ◽  
Author(s):  
Xiao Liang Zhang ◽  
Xu Feng Xie ◽  
Yan Huang
Keyword(s):  
Electroless Plating ◽  
Hydrogen Permeation ◽  
Hydrogen Permeability ◽  
Composite Membranes ◽  
Hydrogen Separation ◽  
High Hydrogen ◽  
Ni Alloy ◽  
Plating Method ◽  
Fcc Phase ◽  
The Ideal

Pd-based composite membranes are the attractive membrane materials for hydrogen separation due to their high hydrogen permeability and infinite permselectivity. Thin pure Ni and Pd-Ni alloy membranes with high hydrogen permeation were prepared by the electroless plating method. It is difficult to prepare the dense pure Ni membranes with 1-2 μm thickness for hydrogen separation. However, Pd-Ni alloy membranes with several micrometers thickness showed good permeation performance. Hydrogen permeance of the Pd95Ni5 alloy membrane with fcc phase up to 3.1×10-6 mol/m2 s Pa and the ideal permselectivity over 600 were obtained at 773 K.

scholarly journals Management of Verticillium Wilt of Avocado Using Tolerant Rootstocks

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 531 ◽  
Author(s):  
Amnon Haberman ◽  
Leah Tsror (Lahkim) ◽  
Silit Lazare ◽  
Marina Hazanovsky ◽  
Sara Lebiush ◽  
...  
Keyword(s):  
Fungal Infection ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Fungal Pathogen ◽  
Significant Variation ◽  
Genetic Variance ◽  
Causal Agent ◽  
Infested Soil ◽  
Abiotic Constraints ◽  
Massive Tree

The global avocado industry is growing, and farmers are seeking to expand their plantations. However, many lands suitable for avocado planting were previously cultivated with hosts of the soil-borne fungal pathogen Verticillium dahliae, which is the causal agent of Verticillium wilt (VW). VW can seriously impair avocado orchards, and therefore, planting on infested soil is not recommended. The use of different rootstock types allows avocado cultivation in various regions with diverse biotic and abiotic constraints. Hence, we tested whether genetic variance among rootstocks may also be used to manage avocado VW. Six hundred trees, mostly Hass and some Ettinger, grafted on 23 selected rootstocks were evaluated for five years in a highly V. dahliae-inoculated plot for VW symptoms, fungal infection, and productivity. The selected rootstocks displayed a significant variation related to VW tolerance, and productive avocado rootstocks with potential VW tolerance were identified. Moreover, the rootstock productivity appears to correlate negatively to the susceptibility level. In conclusion, planting susceptible rootstocks (e.g., VC66, VC152, and VC26) in infested soil increases the likelihood of massive tree loss and low productivity. Whereas, tolerant rootstocks (e.g., VC804 and Dusa) may restrict VW and enable avocado cultivation on infested soils.

Morphology of Verticillium dahliae and V. tricorpus on semi-selective media used for the detection of V. dahliae in soil

2003 ◽  
Vol 107 (7) ◽  
pp. 822-830 ◽  
Author(s):  
Jan-Kees C. Goud ◽  
Aad J. Termorshuizen ◽  
Walter Gams
Keyword(s):  
Verticillium Dahliae ◽  
Selective Media

scholarly journals Fate of Trichoderma harzianum in the olive rhizosphere: time course of the root colonization process and interaction with the fungal pathogen Verticillium dahliae

BioControl ◽  
2015 ◽  
Vol 61 (3) ◽  
pp. 269-282 ◽  
Author(s):  
David Ruano-Rosa ◽  
Pilar Prieto ◽  
Ana María Rincón ◽  
María Victoria Gómez-Rodríguez ◽  
Raquel Valderrama ◽  
...  
Keyword(s):  
Verticillium Dahliae ◽  
Trichoderma Harzianum ◽  
Fungal Pathogen ◽  
Time Course ◽  
Root Colonization ◽  
Colonization Process

Butternut (Juglans cinerea) health, hybridization, and recruitment in the northeastern United States

2014 ◽  
Vol 44 (10) ◽  
pp. 1244-1252 ◽  
Author(s):  
A. Boraks ◽  
K.D. Broders
Keyword(s):  
United States ◽  
Fungal Pathogen ◽  
Natural Hybridization ◽  
Natural Setting ◽  
Northeastern United States ◽  
Juglans Cinerea ◽  
Population Sizes ◽  
Natural Range ◽  
Disease Impact ◽  
Disease Pressure

Butternut (Juglans cinerea L.) trees are being extirpated from their natural range by an epidemic caused by a fungal pathogen. Widespread mortality is reminiscent of past epidemics on American chestnut (Castanea dentata (Marsh.) Borkh.) and American elm (Ulmus americana L.). Butternut has remained relatively understudied, resulting in unsampled areas and gaps in our understanding of this forest epidemic and the future outlook of this species in North America. The previously unsampled area consisting of the northeastern United States was surveyed for the presence of J. cinerea, and several population health metrics were recorded, including recruitment, disease pressure, and hybridization. A total of 252 butternut trees were sampled. Analysis indicates that there is insufficient J. cinerea recruitment to maintain population sizes. Further compounding low recruitment, butternut saplings demonstrate elevated levels of disease impact from the fungal pathogen Ophiognomonia clavigignenti-juglandacearum Broders & Boland. Natural hybridization of butternut with introduced congenics such as Juglans ailantifolia Carrière is strongly associated with lower disease impact. Hybrid trees displayed an average of 2.4 cankers per tree compared with 4.5 cankers for nonhybrid butternut. Further niche and resistance studies are required to assess whether butternut hybrids can replace butternut in a natural setting. It still remains uncertain whether tree size or habitat affect disease impact; however, smaller trees, often residing in riparian habitats, were found to have a greater number of cankers. The data presented here, combined with past studies, provide critical information for use in butternut management strategy plans.

scholarly journals iTRAQ-based proteomics analysis of autophagy-mediated immune responses against the vascular fungal pathogen Verticillium dahliae in Arabidopsis

Autophagy ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 598-618 ◽  
Author(s):  
Fu-Xin Wang ◽  
Yuan-Ming Luo ◽  
Zi-Qin Ye ◽  
Xue Cao ◽  
Jing-Nan Liang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Verticillium Dahliae ◽  
Fungal Pathogen ◽  
Proteomics Analysis

scholarly journals Scarcity of Major Resistance Genes Against Verticillium Dahliae

2021 ◽  
Author(s):  
Jasper P. Vermeulen ◽  
Katharina Hanika ◽  
Bart P.H.J. Thomma ◽  
Yuling Bai ◽  
Henk J Schouten
Keyword(s):  
Resistance Genes ◽  
Verticillium Dahliae ◽  
Fungal Pathogen ◽  
Wilt Disease ◽  
Discriminative Power ◽  
Vascular Wilt ◽  
Virulent Strains ◽  
Canopy Area ◽  
Major Resistance Genes ◽  
Vascular Wilt Disease

Abstract Verticillium dahliae is a soil-borne fungal pathogen that causes vascular wilt disease in numerous plant species. The only described qualitative resistances against V. dahliae are the Ve1 gene and the V2 locus in tomato. These resistances have been overcome by virulent strains. We tried to identify additional resistances. Out of the methods we tested, comparing the canopy area of V. dahliae-inoculated plants with mock-inoculated plants yielded the best discriminative power in resistance tests. Out of six wild tomato accessions that were previously reported to possess some resistance, Solanum pimpinellifolium G1.1596 and S. cheesmanii G1.1615 displayed the lowest stunting and the least colonization by V. dahliae. Recombinant inbred line (RIL) populations were developed of both populations. No QTLs were identified in the G1.1596 RIL population. In the G1.1615 population, four small-effect QTLs were associated with reduced stunting. Many studies in other hosts also failed to discover major resistance genes against V. dahliae. We hypothesize that the scarcity of major resistance genes against V. dahliae is caused by its endophytic behaviour in nature. The limited damage in nature would not lead to evolutionary pressure to evolve major resistances. However, in agriculture V. dahliae can behave more pathogenic, leading to serious damage.

scholarly journals The Cotton Apoplastic Protein CRR1 Stabilizes Chitinase 28 to Facilitate Defense against the Fungal Pathogen Verticillium dahliae

2019 ◽  
Vol 31 (2) ◽  
pp. 520-536 ◽  
Author(s):  
Li-Bo Han ◽  
Yuan-Bao Li ◽  
Fu-Xin Wang ◽  
Wen-Yan Wang ◽  
Jun Liu ◽  
...  
Keyword(s):  
Verticillium Dahliae ◽  
Fungal Pathogen

scholarly journals Disruption and Overexpression of the Gene Encoding ACC (1-Aminocyclopropane-1-Carboxylic Acid) Deaminase in Soil-Borne Fungal Pathogen Verticillium dahliae Revealed the Role of ACC as a Potential Regulator of Virulence and Plant Defense

2019 ◽  
Vol 32 (6) ◽  
pp. 639-653 ◽  
Author(s):  
Maria-Dimitra Tsolakidou ◽  
lakovos S. Pantelides ◽  
Aliki K. Tzima ◽  
Seogchan Kang ◽  
Epaminondas J. Paplomatas ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Plant Defense ◽  
Verticillium Dahliae ◽  
Fungal Pathogen ◽  
Acc Deaminase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Gene Encoding ◽  
Pathogen Virulence ◽  
Plant Growth Promoting

It has been suggested that some microorganisms, including plant growth–promoting rhizobacteria, manipulate the level of ethylene in plants by degrading 1-aminocyclopropane-1-carboxylic acid (ACC), an ethylene precursor, into α-ketobutyrate and ammonia, using ACC deaminase (ACCd). Here, we investigated whether ACCd of Verticillium dahliae, a soil-borne fungal pathogen of many important crops, is involved in causing vascular wilt disease. Overexpression of the V. dahliae gene encoding this enzyme, labeled as ACCd, significantly increased virulence in both tomato and eggplant, while disruption of ACCd reduced virulence. Both types of mutant produced more ethylene than a wild-type (70V-WT) strain, although they significantly differed in ACC content. Overexpression strains lowered ACC levels in the roots of infected plants, while the amount of ACC in the roots of plants infected with deletion mutants increased. To test the hypothesis that ACC acts as a signal for controlling defense, roots of WT and Never-ripe (Nr) tomato plants were treated with ACC before V. dahliae inoculation. Plants pretreated with ACC displayed less severe symptoms than untreated controls. Collectively, our results suggest a novel role of ACC as a regulator of both plant defense and pathogen virulence.

Combining Metric Aerial Photography and Near‐Infrared Videography to Define Within‐Field Soil Sampling Frameworks

2003 ◽  
Vol 18 (4) ◽  
pp. 13-20 ◽  
Author(s):  
G. G. Wright ◽  
K. B. Matthews ◽  
J. C. Tapping ◽  
R. Wright
Keyword(s):  
Aerial Photography ◽  
Near Infrared ◽  
Soil Sampling ◽  
Field Soil
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