scholarly journals Wood necrosis in esca-affected vines: types, relationships and possible links with foliar symptom expression

OENO One ◽  
2012 ◽  
Vol 46 (1) ◽  
pp. 15 ◽  
Author(s):  
Névile Maher ◽  
J. Piot ◽  
Sylvie Bastien ◽  
Jessica Vallance ◽  
Patrice Rey ◽  
...  
Keyword(s):  
Logistic Model ◽  
Single Unit ◽  
White Rot ◽  
Cabernet Sauvignon ◽  
Symptom Expression ◽  
Foliar Symptoms ◽  
Esca Disease ◽  
Foliar Symptom ◽  
Different Types ◽  
Internal Necrosis

<p style="text-align: justify;"><strong>Aims</strong>: Esca disease of grapevine is characterised by foliar symptoms associated with the development of various internal wood necroses. The aims of the present study are to determine the type and the quantity of necroses in the various woody compartments of vines, the relationships between them and the links between necroses and severity of foliar symptoms.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Symptomatic and asymptomatic vines cv Cabernet- Sauvignon were cross-sectioned to quantify the different types of internal necrosis in the scions (cordons, heads, and trunks) and rootstocks. Five necrosis « variables » were accounted for: central necrosis, sectorial necrosis, mixed necrosis, white rot, altered perimeter and in addition to the variable healing cone. In the scion, for all types of necrosis variables, a significant correlation between compartments was found. Vines with acute foliar form of esca had very advanced peripheral tissue degradations in the xylem and cambial zones. Chronic foliar expression of esca was associated with quantity of internal necroses higher than those obtained for asymptomatic vines. A logistic model indicated that white rot in the cordons was the best predictor for the chronic form of esca.</p><p style="text-align: justify;"><strong>Conclusion</strong>: Necroses formed a continuum within the plant. The scion is like a single unit with a volume of necroses useful to determine the health status of vines.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: A quantitative analysis of vine internal necroses would open up new possibilities for esca-epidemic approaches.</p>

scholarly journals Foliar Symptom Expression of Wood Decay in Actinidia deliciosa in Relation to Environmental Factors

Plant Disease ◽  
2008 ◽  
Vol 92 (8) ◽  
pp. 1150-1157 ◽  
Author(s):  
Stefano Di Marco ◽  
Fabio Osti
Keyword(s):  
Wood Decay ◽  
Soil Characteristics ◽  
Annual Incidence ◽  
Actinidia Deliciosa ◽  
Symptom Expression ◽  
Foliar Symptoms ◽  
Foliar Symptom ◽  
Different Types ◽  
Wood Deterioration ◽  
First Time

Kiwifruit vines (Actinidia deliciosa var. deliciosa) have recently been affected by a new form of decay caused by several fungi that produce different types of wood deterioration in the trunk and cordons. Surveys were conducted over a period of 5 years to investigate epidemiological aspects of the disease in a typical Italian growing area (Emilia-Romagna), where kiwifruit is widely cultivated and where the disease was noted for the first time. The disease was widespread over the kiwifruit growing area surveyed, and its incidence increased over the course of the survey. No relationship was found between vineyard soil characteristics or management methods and the annual incidence of symptomatic vines. Foliar symptoms did not consistently express every season even on obviously infected vines. The time of appearance and the development of the disease were correlated with plant phenology and temperature. In particular, from June to August, temperature seemed to affect the annual incidence of the disease in terms of both symptomatic shoots and symptomatic vines. The aspects in common between the decay of kiwifruit and esca of grapevine could be hypothesized and are discussed.

scholarly journals Current knowledge on Grapevine Trunk Diseases with complex etiology: a systemic approach

2020 ◽  
Vol 59 (1) ◽  
pp. 29-53
Author(s):  
Marion CLAVERIE ◽  
Martin NOTARO ◽  
Florence FONTAINE ◽  
Jacques WERY
Keyword(s):  
Conceptual Model ◽  
Current Knowledge ◽  
Management Strategies ◽  
Symptom Expression ◽  
Grapevine Trunk Diseases ◽  
Foliar Symptoms ◽  
Starting Point ◽  
Foliar Symptom ◽  
Botryosphaeria Dieback ◽  
Trunk Diseases

Among all causes of grapevine decline, Grapevine Trunk Diseases (GTDs) are major concerns for grape growers. This paper reviews knowledge and proposes hypotheses on two major GTDs, esca and Botryosphaeria dieback, and assembles a conceptual model. The objective was to collect information into a sequence, from grapevine nursery propagation processes, through foliar symptom expression, to plant death in mature vineyards. Pathogen infection and colonization steps in woody vine tissues, and the hypotheses that have been formulated to explain the outburst of foliar symptoms, are reported and discussed. Factors that could aggravate or repress GTD symptoms and incidence expansion are also addressed. Vine physiology and pathology together could expand understanding of these diseases. Knowledge and hypotheses that need validation are summarized, and a conceptual model is proposed to explain the occurrence of symptoms and the influencing factors. The model could be useful to cope with the complexity of GTDs, and as a starting point for research to unravel knowledge gaps and suggest new disease management strategies.

scholarly journals Trunk Surgery as a Tool to Reduce Foliar Symptoms in Diseases of the Esca Complex and Its Influence on Vine Wood Microbiota

2021 ◽  
Vol 7 (7) ◽  
pp. 521
Author(s):  
Andrea Pacetti ◽  
Samuele Moretti ◽  
Catia Pinto ◽  
Stéphane Compant ◽  
Sibylle Farine ◽  
...  
Keyword(s):  
Alpha Diversity ◽  
Cabernet Sauvignon ◽  
Symptom Reduction ◽  
Symptom Expression ◽  
Decayed Wood ◽  
Biochemical Pathway ◽  
Leaf Stripe ◽  
Mechanical Removal ◽  
Foliar Symptoms ◽  
Fomitiporia Mediterranea

In the last few years, trunk surgery has gained increasing attention as a method to reduce foliar symptoms typical of some of the Esca complex diseases. The technique relies on the mechanical removal of decayed wood by a chainsaw. A study on a 14-year-old Cabernet Sauvignon vineyard was carried out to validate the efficacy of trunk surgery and explore possible explanations behind it. Three levels of treatment were applied to three of the most characteristic symptoms associated with some diseases of the Esca complex, such as leaf stripe symptoms (LS), wilted shoots (WS) and apoplexy (APP). The most promising results were obtained by complete trunk surgery, where the larger decay removal allowed lower symptom re-expression. According to the wood types analyzed (decay, medium and sound wood), different changes in microbiota were observed. Alpha-diversity generally decreased for bacteria and increased for fungi. More specifically, main changes were observed for Fomitiporia mediterranea abundance that decreased considerably after trunk surgery. A possible explanation for LS symptom reduction after trunk surgery could be the microbiota shifting caused by the technique itself affecting a microbic-shared biochemical pathway involved in symptom expression.

Foliar Symptom Expression in Association with Early Infection and Xylem Colonization by Fusarium virguliforme (formerly F. solani f. sp. glycines), the Causal Agent of Soybean Sudden Death Syndrome

2008 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Shrishail S. Navi ◽  
X. B. Yang
Keyword(s):  
Sudden Death ◽  
Root Hairs ◽  
Petri Dish ◽  
Sudden Death Syndrome ◽  
Symptom Expression ◽  
Conidial Suspension ◽  
Fusarium Virguliforme ◽  
Scanning Electron Microscope Study ◽  
Foliar Symptoms ◽  
Foliar Symptom

Soybean sudden death syndrome (SDS), caused by Fusarium virguliforme (FV), is a root disease that results in severe foliar symptoms during the reproductive stage. In a regular growing season, an epidemic of SDS is highly correlated with the planting date and the disease tends to be more severe in earlier planted soybeans. Occurrence of infection early in the season is likely to result in colonization in the xylem and phloem tissues, a process essential for foliar symptom expression because xylem tissues are upward pathways in soybean plants. To demonstrate the biology of this infection, we used an effective and quantifiable seedling inoculation technique in which germinated seeds in a Petri dish were spray-inoculated with conidial suspension before being transplanted. Plants that had foliar symptoms showed both external and internal discolored taproots and basal stems, while plants with no foliar symptoms had only superficial discoloration. Microtome sectioning of taproots of plants that had foliar symptoms revealed the presence of fungal structures in both xylem and phloem tissues, while plants that had no foliar symptoms revealed fungal structures only in phloem tissue. A scanning electron microscope study showed a higher penetration frequency of FV near the root-cap zone where few or no root hairs of the radicle were found. These results indicate that fungal penetration into the xylem tissue plays a role in foliar symptom expression. Accepted for publication 10 December 2007. Published 22 February 2008.

scholarly journals The Influence of Grapevine Cultivar and Isolate of Eutypa lata on Wood and Foliar Symptoms

Plant Disease ◽  
2007 ◽  
Vol 91 (8) ◽  
pp. 924-931 ◽  
Author(s):  
M. R. Sosnowski ◽  
R. Lardner ◽  
T. J. Wicks ◽  
E. S. Scott
Keyword(s):  
Management Strategies ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Cabernet Sauvignon ◽  
Eutypa Lata ◽  
Rate Of Spread ◽  
Grapevine Cultivar ◽  
Eutypa Dieback ◽  
Foliar Symptoms ◽  
Foliar Symptom

Grapevine cultivar (Vitis vinifera) and isolate of Eutypa lata influence wood and foliar symptoms of Eutypa dieback. Foliar symptoms of Eutypa dieback developed within 8 months of inoculating young grapevines (cvs. Grenache, Cabernet Sauvignon, and Merlot) in a shadehouse. Isolates of E. lata from various wine regions in southern Australia varied in their ability to colonize inoculated grapevines and induce wood and foliar symptoms. Grapevine cultivars varied for wood and foliar symptom expression but not for mycelial colonization. However, the severity of foliar symptoms was not related to the rate of spread of the fungus in the grapevine. Furthermore, the staining of wood typically attributed to E. lata did not reflect the presence of the fungus because the fungus was detected up to 80 mm beyond the stain. A field trial with mature grapevines revealed significant differences in the rate of spread of wood staining due to E. lata among eight cultivars, with up to 50 mm/year detected in Cabernet Sauvignon and Shiraz grapevines. In the shadehouse, the maximum growth rate of E. lata was recorded to be 115 mm/year for Grenache rootlings. Information from this study may help to optimize management strategies for maintaining productivity of grapevines with Eutypa dieback, thus reducing the economic impact of the disease.

scholarly journals Alterations in Grapevine Leaf Metabolism Occur Prior to Esca Apoplexy Appearance

2017 ◽  
Vol 30 (12) ◽  
pp. 946-959 ◽  
Author(s):  
Maryline Magnin-Robert ◽  
Marielle Adrian ◽  
Sophie Trouvelot ◽  
Alessandro Spagnolo ◽  
Lucile Jacquens ◽  
...  
Keyword(s):  
Symptom Expression ◽  
Glutathione Level ◽  
Glutathione S Transferase ◽  
Grapevine Trunk Diseases ◽  
Esca Disease ◽  
Foliar Symptom ◽  
Trunk Diseases ◽  
Preferential Location ◽  
Preceding Symptom

Esca disease is one of the major grapevine trunk diseases in Europe and the etiology is complex, since several inhabiting fungi are identified to be associated with this disease. Among the foliar symptom expressions, the apoplectic form may be distinguished and characterized by sudden dieback of shoots, leaf drop, and shriveling of grape clusters in a few days that can ultimately induce the plant death. To further understand this drastic event, we conducted transcriptomic and metabolomic analyses to characterize responses of leaves during the period preceding symptom appearance (20 and 7 days before foliar symptom expression) and at the day of apoplexy expression. Transcriptomic and metabolomic analyses provide signatures for the apoplectic leaves and most changes concerning the metabolism of carbohydrates, amino acids, and phenylpropanoids. In deciphering glutathione-S-transferase (GST), its preferential location in phloem, correlated with the upregulation of GST genes and a decrease of the glutathione level, offers further support to the putative role of glutathione during apoplexy expression.

scholarly journals Comparative investigations on different types of inductors in single-phase inverter

2021 ◽  
Vol 2107 (1) ◽  
pp. 012051
Author(s):  
M. Z. Aihsan ◽  
A. M. Yusof ◽  
Hasliza A Rahim ◽  
B. Ismail ◽  
W. A. Mustafa ◽  
...  
Keyword(s):  
Pulse Width ◽  
Single Unit ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Bridge Circuit ◽  
Experimental Assessment ◽  
Phase Inverter ◽  
Different Types ◽  
Single Phase Inverter ◽  
Validation Of Results

Abstract This article organized in two sections where it compares the performance of single-phase inverters using various types of inductors with differences modulation technique of pulse width modulation (PWM). Not all inductors perform the same function, even the inductance value is the same. The study will investigate the capability of each inductor on its performance to convert the unfiltered AC voltage into filtered sinusoidal AC voltage. The drum core and toroidal core inductors were used in this investigation. For both inductors, the performance will be analyzed based on Bipolar and Unipolar switching schemes in a single unit H-bridge circuit. The validation of results are through experimental assessment only and it will be evaluating the shape of sinusoidal AC voltage and the content of total harmonics distortion in the AC voltage for both inductors.

Effect of Potato virus Y on Yield of Three Potato Cultivars Grown Under Different Nitrogen Levels

Plant Disease ◽  
2006 ◽  
Vol 90 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Jonathan L. Whitworth ◽  
Phil Nolte ◽  
Chris McIntosh ◽  
Robert Davidson
Keyword(s):  
Potato Virus ◽  
Potato Virus Y ◽  
Total Yield ◽  
Russet Burbank ◽  
Yield Reduction ◽  
Symptom Expression ◽  
Russet Norkotah ◽  
Nitrogen Levels ◽  
Foliar Symptoms ◽  
Significant Yield

Previous studies have shown that Potato virus Y (PVY) reduces yield in many cultivars. Typical foliar symptoms can include veinal necrosis, leaf drop, and a mosaic pattern sometimes accompanied by leaf roughness. Infection by PVY in Russet Burbank produces identifiable PVY symptoms, whereas cv. Russet Norkotah expresses mild, almost latent symptoms. Yield also is influenced by nitrogen fertilizer levels. This research was conducted to determine whether increased nitrogen mitigates yield reduction caused by PVY. Russet Norkotah, CO80011-5, and Russet Burbank were used in replicated plots of non-PVY-infected and PVY-infected plants at three nitrogen levels in 1995 and 1996. There was a significant yield reduction between PVY-negative and PVY-positive plots in all cultivars, at most nitrogen levels. PVY yield reduction was similar (approximately 38%) in the mild symptom expression clones of Russet Norkotah and CO80011-5, whereas the yield reduction in Russet Burbank, which exhibits typical symptom expression, was 63.5%. We conclude that increased nitrogen can influence total yield, but does not significantly mitigate the yield reduction due to PVY infection.

Birch foliar responses to simulated acidic fog and Septoria betulae inoculations

2001 ◽  
Vol 31 (3) ◽  
pp. 392-400
Author(s):  
K B Kouterick ◽  
J M Skelly ◽  
S P Pennypacker ◽  
R M Cox
Keyword(s):  
Bay Of Fundy ◽  
Betula Papyrifera ◽  
Mature Trees ◽  
The Past ◽  
Foliar Symptoms ◽  
Foliar Symptom ◽  
Foliar Senescence ◽  
Symptomatic Leaf ◽  
Acidic Fog ◽  
Ph Level

The effects of simulated acidic fog and inoculation with Septoria betulae Pass. on foliar symptom development and foliar senescence of Betula papyrifera Marsh. and Betula cordifolia Regel seedlings were investigated in 1997 and 1998 under greenhouse conditions. An interactive role may exist between acidic fog events and S. betulae in causing birch foliar browning, a disease reported over the past decade to occur on mature trees growing adjacent to the Bay of Fundy, Canada. Seedlings received applications of simulated fog adjusted to pH 3.2, 4.2, and 5.6 or a no-fog treatment. Inoculation treatments at each fog pH level were accomplished through spray atomization with S. betulae conidial suspensions and by placing naturally infected birch leaves bearing pycnidia of the fungus on plastic nets suspended above seedlings in enclosed chambers. Percent symptomatic leaf area of seedlings inoculated with S. betulae was nearly double that recorded for non-inoculated seedlings. Foliar browning resembled symptoms observed on mature trees in the field. Foliar symptoms were observed on non-inoculated seedlings, with greater severities associated with seedlings exposed to the most acidic fog treatment. Leaf senescence was also greatest for spray-inoculated leaves that had been exposed to the pH 3.2 fog treatment. Pycnidial development was not influenced by the pH of the fog treatments but was greater in all fog treatments than in no-fog treatments. Although both acidic fog and S. betulae infection are able to cause symptoms independently, the data suggest that an interactive role may exist in causing birch foliar browning. However, to obtain the same severity of foliar browning as observed on natural forest-grown trees in the Bay of Fundy region, S. betulae must be present.

scholarly journals A Novel Genetic Variant of Grapevine leafroll-associated virus-3 (GLRaV-3) from Idaho Grapevines

Plant Disease ◽  
2019 ◽  
Vol 103 (3) ◽  
pp. 509-518 ◽  
Author(s):  
Brandon D. Thompson ◽  
Jennifer Dahan ◽  
Jungmin Lee ◽  
Robert R. Martin ◽  
Alexander V. Karasev
Keyword(s):  
Nucleotide Sequence ◽  
Genetic Variant ◽  
Scale Insects ◽  
Cabernet Sauvignon ◽  
Rt Pcr ◽  
Wine Grapes ◽  
Phylogenetic Groups ◽  
Sequence Identity ◽  
Foliar Symptoms ◽  
Major Constraint

Grapevine leafroll-associated virus-3 (GLRaV-3) is a major constraint on profitable grapevine cultivation. The virus is transmitted efficiently by mealybugs and soft scale insects, or through vegetative propagation by cuttings, and is present worldwide, wherever grapevines are grown. GLRaV-3 exists as a complex of genetic variants currently classified in several phylogenetic groups that can differ from each other by as much as 30% in nucleotide sequence of the whole genome. In the course of the GLRaV-3 testing of wine grapes in southern Idaho, plants of two grapevine cultivars were found to harbor a novel genetic variant of GLRaV-3, named ID45, which exhibited ≤80% nucleotide sequence identity level to the known GLRaV-3 isolates in its most conserved HSP70h gene. The ID45 variant caused no foliar symptoms in ‘Cabernet Sauvignon’ in the fall, and was demonstrated to have poor reactivity to commercial virus-specific antibodies. The entire 18,478-nt genome sequence of the GLRaV-3-ID45 was determined using a combination of high-throughput and conventional Sanger sequencing, and demonstrated to have typical organization for the genus Ampelovirus (family Closteroviridae), with only 70 to 77% identity level to the GLRaV-3 genomes from other established phylogroups. We concluded that ID45 represented a new phylogenetic group IX of GLRaV-3. Database search using ID45 nucleotide sequence as a query suggested that this novel ID45 variant is present in at least one other grape-growing state in the U.S., California, and in Brazil. An RT-PCR based test was developed to distinguish ID45 from the predominant GLRaV-3 phylogroup I found in Idaho in single and mixed infections.

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