Verticillium wilt of chrysanthemum: colonization of leaves in relation to symptom development

1971 ◽  
Vol 49 (2) ◽  
pp. 181-185 ◽  
Author(s):  
R. Hall ◽  
L. V. Busch
Keyword(s):  
Verticillium Wilt ◽  
Significant Contribution ◽  
Vascular System ◽  
Symptom Expression ◽  
Rapid Rise ◽  
Symptom Development ◽  
Flower Buds ◽  
Advanced Stages ◽  
Wilt Symptom ◽  
Leaf Exudate

The vascular system of leaves of chrysanthemum plants inoculated with Verticillium dahliae was invaded by mycelium before the appearance of visible wilt symptoms. After flower buds appeared a rapid rise in the number of propagules of fungus in the leaf was followed by a rise in severity of visible wilt symptom expression and conductivity of leaf exudate. Those portions of the leaf with the most advanced stages of wilt contained the greatest amounts of fungus. It is suggested that the mycelium within the leaf makes a significant contribution to the development of symptoms of wilt.

Verticillium wilt of chrysanthemum: suppression of fungal colonization of leaves and prevention of wilt symptom development by foliar applications of benomyl

1971 ◽  
Vol 49 (11) ◽  
pp. 1987-1991 ◽  
Author(s):  
Lloyd V. Busch ◽  
Robert Hall
Keyword(s):  
Verticillium Wilt ◽  
Fungal Growth ◽  
Tween 20 ◽  
Fungal Colonization ◽  
Systemic Fungicide ◽  
Symptom Expression ◽  
Symptom Development ◽  
Fungal Activity ◽  
Single Leaf ◽  
Wilt Symptom

This report describes the use of a systemic fungicide in a study of the relation between fungal colonization of a plant and symptom expression. The systemic fungicide benomyl (methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate) was used to selectively suppress development of Verticillium dahliae in leaves of chrysanthemum plants infected via the roots.Benomyl sprayed or painted onto foliage at weekly intervals as a 20 mg/liter solution in 0.25% aqueous Tween 20 restricted development of V. dahliae in leaves and prevented wilt symptom development. Numbers of propagules of V. dahliae recovered from stems of symptomless benomyl-treated plants were similar to those recovered from stems of untreated inoculated plants expressing wilt symptoms. Material toxic to Verticillium was detected in leaves but not in stems of plants receiving foliar paint applications of benomyl. Benomyl applied repeatedly to a single leaf on an inoculated plant suppressed fungal growth and symptom development in that leaf while untreated leaves wilted and became necrotic in the usual way. The observations support the hypothesis that symptom expression in leaves of chrysanthemum plants infected with Verticillium is largely due to fungal activity within infected leaves rather than fungal activity in the roots or stem.

SSH reveals a linkage between a senescence-associated protease and Verticillium wilt symptom development in lettuce (Lactuca sativa)

2011 ◽  
Vol 76 (1) ◽  
pp. 48-58 ◽  
Author(s):  
Steven J. Klosterman ◽  
Amy Anchieta ◽  
Maria D. Garcia-Pedrajas ◽  
Karunakaran Maruthachalam ◽  
Ryan J. Hayes ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Lactuca Sativa ◽  
Symptom Development ◽  
Wilt Symptom

scholarly journals Development, Detection, and Elimination of Verticillium dahliae in Mint Shoot Cultures

HortScience ◽  
2003 ◽  
Vol 38 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Nan Wang ◽  
Barbara M. Reed
Keyword(s):  
Verticillium Dahliae ◽  
Shoot Tips ◽  
Potato Dextrose Agar ◽  
Shoot Length ◽  
Symptom Expression ◽  
Shoot Cultures ◽  
Symptom Development ◽  
Symptom Ratings ◽  
Wilt Symptom

Roots of greenhouse-grown mint plants and in-vitro-grown shoot cultures were inoculated with Verticillium dahliae Kleb. conidial suspensions to study wilt symptom development and detection and elimination of the fungus. There were significant differences in the symptom expression between control and infected shoot cultures at all conidia concentrations for the four mints tested. Disease-symptom ratings were proportional to the V. dahliae inoculum density. Infected shoot cultures were stunted when inoculated with ≥ 103 conidia/mL. Verticillium dahliae was re-isolated from infected shoot cultures at all levels of inoculum, but not from any control cultures. Verticillium infections were easily detected by plating mint stems on potato dextrose agar. Shoot tips (0.5 to 15 mm) from infected in-vitro- and greenhouse-grown plants were isolated and screened for fungus. The most effective shoot length for fungus elimination was 3-5 mm. Shoot tips isolated from in vitro spearmint cultivars infected at 102 and 103 conidia/mL were 100% Verticillium free, but only 42% of `Black Mitcham' and 54% of `Todd's Mitcham' peppermints were free of the disease. Shoot tips from infected greenhouse plants produced Verticillium-free cultures from 79% of `Black Mitcham' and 90% of `Todd's Mitcham' plants. These results indicate the utility of testing for Verticillium and the safety of micropropagated mint shoots for certified planting stock programs.

scholarly journals Clinical Application of Novel Therapies for Coronary Angiogenesis: Overview, Challenges, and Prospects

2021 ◽  
Vol 22 (7) ◽  
pp. 3722
Author(s):  
Mohamed Sabra ◽  
Catherine Karbasiafshar ◽  
Ahmed Aboulgheit ◽  
Sidharth Raj ◽  
M. Ruhul Abid ◽  
...  
Keyword(s):  
Vascular System ◽  
Therapeutic Angiogenesis ◽  
Clinical Findings ◽  
Preclinical Studies ◽  
Novel Therapies ◽  
Future Prospects ◽  
Surgical Interventions ◽  
Therapeutic Modalities ◽  
Advanced Stages ◽  
Coronary Angiogenesis

Cardiovascular diseases continue to be the leading cause of death worldwide, with ischemic heart disease as the most significant contributor. Pharmacological and surgical interventions have improved clinical outcomes, but are unable to ameliorate advanced stages of end-heart failure. Successful preclinical studies of new therapeutic modalities aimed at revascularization have shown short lasting to no effects in the clinical practice. This lack of success may be attributed to current challenges in patient selection, endpoint measurements, comorbidities, and delivery systems. Although challenges remain, the field of therapeutic angiogenesis is evolving, as novel strategies and bioengineering approaches emerge to optimize delivery and efficacy. Here, we describe the structure, vascularization, and regulation of the vascular system with particular attention to the endothelium. We proceed to discuss preclinical and clinical findings and present challenges and future prospects in the field.

Vascular coating: a barrier to colonization by the pathogen in Verticillium wilt of tomato

1989 ◽  
Vol 67 (2) ◽  
pp. 600-607 ◽  
Author(s):  
Jane Robb ◽  
D. A. Powell ◽  
P. F. S. Street
Keyword(s):  
Disease Resistance ◽  
Verticillium Wilt ◽  
Water Samples ◽  
Light Microscope ◽  
Trapping Site ◽  
Symptom Expression ◽  
Susceptible Tomato ◽  
Ve Gene ◽  
Verticillium Albo Atrum

Massive infusion of conidia of Verticillium albo-atrum Reinke & Berthier induced synchronous secretion of vascular coating in the petiolar xylem vessels of resistant and susceptible tomato near-isolines. More coating formed earlier in resistant than in susceptible plants. In the susceptible plants secretion was delayed in colonized trapping site vessels, but initiated in surrounding uncolonized ones. Controls were infused with water. Samples were quantified by light microscope assay techniques at 18, 48, and 120 h postinoculation for the following parameters: (i) delayed coating effect, (ii) overall coating capacity, and (iii) ability of fungus to "escape" laterally from trapping site vessels. The results showed that susceptibility to Verticillium was absolutely correlated with the presence of the delayed coating effect in the plant and increased ability of the fungus to spread laterally. Treatment of inoculated resistant plants with an inhibitor of coating secretion resulted in conversion to the susceptible phenotype. The progeny of a genetic backcross for the dominant (Ve) and recessive (ve) alleles at the Ve locus (Velve × velve) were assayed for the same parameters as well as for disease resistance based on symptom expression. The results confirmed the previous observations and suggested that in tomato the delayed phenotype is recessive. The data strongly supports two hypotheses: (i) coating forms a barrier against fungal penetration and (ii) the timing of the coating response in trapping site vessels results, directly or indirectly, from expression of the Ve gene.

Cyanogenic potential of Trifolium repens L. in relation to pepper spot caused by Stemphylium sarciniforme

1978 ◽  
Vol 56 (20) ◽  
pp. 2491-2496 ◽  
Author(s):  
H. T. Wilkinson ◽  
R. L. Millar
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Fungal Colonization ◽  
Symptom Expression ◽  
Symptom Development ◽  
Cyanogenic Glucosides ◽  
Fungal Development ◽  
Cyanogenic Potential ◽  
Trifolium Repens L ◽  
Whole Mounts

White clover (Trifolium repens L.) contains two cyanogenic β-glucosides (G), linamarin and lotaustralin. Upon injury to the tissues a β-glucosidase (E) effects the release of cyanide from the β-glucosides. Four selections of white clover differing in cyanogenic properties (G+E+, G+E−, G−E+, G−E−) were examined for differences in susceptibility to Stemphylium sarciniforme. Symptom development was determined at 24, 48, 72, 96, and 120 h after the leaves were inoculated. Symptoms for all four selections consisted initially of small brown flecks (1 mm in diameter), then dark spots (1–2 mm in diameter) with definite borders, and finally senescence and wilt of the interlesion tissue. Plants containing both β-glucosidase (EC 3.2.1.21)and cyanogenic glucosides (G+E+) and those with only glucosides (G+E−) developed symptoms 24 h earlier than did the G−E+ and G−E− selections. The earliest symptoms were observed at 48 h; by 96 h all four selections showed comparable degrees of senescence and wilt. Pathogen development in infected leaves prepared as whole mounts was examined microscopically. Through 72 h after inoculation, development of S. sarciniforme in the G+E+ and G+E− selections was slower than in the G−E+ selections. By 96 h, however, fungal development in all four selections was comparable; commencement of leaf senescence coincided with extensive fungal colonization of necrotic tissue. Accelerated rates of symptom expression and retarded pathogen development apparently were positively correlated with cyanogenic potential of each white clover selection. Necrosis of suscept tissue was not correlated with cyanogenic potential of each selection.

The copper, iron and lead contents of a series of livers from normal foetal and new-born lambs

1947 ◽  
Vol 37 (4) ◽  
pp. 337-341 ◽  
Author(s):  
E. I. McDougall
Keyword(s):  
Significant Contribution ◽  
Full Term ◽  
Rapid Rise ◽  
Suckling Period ◽  
New Born ◽  
Normal Humans ◽  
Ewe's Milk ◽  
Age Series

The copper, iron and lead contents were determined on an age series of foetal livers obtained during the latter half of pregnancy from normal ewes at Cambridge. The total amounts of the metals showed a rapid rise during the last 3 weeks of gestation due to an increase in the size of the organ and in the actual concentrations. Towards full term and in the new-born animal the results showed an increasing variation which even extended to twins. It is noted that foetal transference takes place without affecting the blood copper of the ewe or causing a physiological anaemia of pregnancy. The time at which the process is at its height is correlated with experience in the prophylaxis of swayback. It is estimated that the store of copper at birth may tide the lamb through the suckling period but the store of iron requires to be supplemented by the diet and that the ewe's milk may make a significant contribution towards this. The small amounts of lead found were of the same order as reported for normal humans and in swayback lambs in Derbyshire; hence the latter cannot be regarded as abnormal.

scholarly journals Physiological response of grapevines to vascular pathogens a review

2011 ◽  
Vol 64 ◽  
pp. 7-16 ◽  
Author(s):  
D.C. Mundy ◽  
M.A. Manning
Keyword(s):  
Physiological Response ◽  
Vascular System ◽  
Physiological Stress ◽  
Wound Response ◽  
Symptom Expression ◽  
Response Information ◽  
Successful Infection ◽  
Trunk Diseases ◽  
Vascular Pathogens ◽  
One Year

The successful infection of a grapevine vascular system by a plant pathogen and expression of disease symptoms occur only when the pathogen has overcome the wound response and other defences of the vine Even when pathogens do successfully infect the vascular system of grapevines symptom expression is not often observed in the first season Symptoms may be observed in one year but the same vine can have reduced or no symptoms the following season Information is presented on physiological stress in association with trunk diseases as one factor that may contribute to symptom expression in vines A hypothesis of grapevine wound response is proposed as part of the discussion of vine physiological response Information on individual trunk diseases and physiological interactions is also provided

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