A Natural Reservoir and Transmission Vector of Grapevine Vein Clearing Virus

Grapevine vein clearing virus (GVCV) is associated with a vein-clearing and vine-decline disease. In this study, we surveyed wild Ampelopsis cordata from the Vitaceae family and found that 31% (35 of 113) of native A. cordata plants are infected with GVCV. The full-length genome sequence of one GVCV isolate from A. cordata shared 99.8% identical nucleotides with an isolate from a nearby cultivated ‘Chardonel’ grapevine, suggesting the occurrence of an insect vector. To identify a vector, we collected Aphis illinoisensis (common name: grape aphids) from wild A. cordata plants and detected GVCV in the aphid populations. We found that A. illinoisensis is capable of transmitting GVCV from infected A. cordata to Chardonel grapevines in the greenhouse. Upon transmission, GVCV caused severe symptoms on the infected Chardonel 45 days post transmission. We conclude that wild GVCV isolates from A. cordata are capable of inducing a severe disease on cultivated grapevines once they spread from native A. cordata to vineyards via grape aphids. The discovery of a natural reservoir and an insect vector of GVCV provides timely knowledge for disease management in vineyards and critical clues on viral evolution and epidemiology.

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Association of a Novel DNA Virus with the Grapevine Vein-Clearing and Vine Decline Syndrome

Phytopathology ◽

10.1094/phyto-02-11-0034 ◽

2011 ◽

Vol 101 (9) ◽

pp. 1081-1090 ◽

Cited By ~ 73

Author(s):

Yu Zhang ◽

Kashmir Singh ◽

Ravneet Kaur ◽

Wenping Qiu

Keyword(s):

United States ◽

Small Rnas ◽

The United States ◽

Wide Distribution ◽

Whole Genome Sequence ◽

Cdna Libraries ◽

Dna Virus ◽

Vein Clearing ◽

Vine Decline ◽

Midwest Region

A severe vein-clearing and vine decline syndrome has emerged on grapevines (Vitis vinifera) and hybrid grape cultivars in the Midwest region of the United States. The typical symptoms are translucent vein-clearing on young leaves, short internodes and decline of vine vigor. Known viral pathogens of grapevines were not closely associated with the syndrome. To obtain a comprehensive profile of viruses in a diseased grapevine, small RNAs were enriched and two cDNA libraries were constructed from a symptomatic grapevine and a symptomless grapevine, respectively. Deep sequencing of the two cDNA libraries showed that the most abundant viral small RNAs align with the genomes of viruses in the genus Badnavirus, the family Caulimoviridae. Amplification of the viral DNA by polymerase chain reaction allowed the assembly of the whole genome sequence of a grapevine DNA virus, which shared the highest homology with the Badnavirus sequences. This is the first report of a DNA virus in grapevines. The new DNA virus is closely associated with the vein-clearing symptom, and thus has been given a provisional name Grapevine vein clearing virus (GVCV). GVCV was detected in six grapevine cultivars showing vein-clearing and vine decline syndrome in Missouri, Illinois, and Indiana, suggesting its wide distribution in the Midwest region of the United States. Discovery of DNA viruses in grapevines merits further studies on their epidemics and economic impact on grape production worldwide.

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Role ofMonosporascus cannonballusand Other Fungi in a Root Rot/Vine Decline Disease of Muskmelon

Plant Disease ◽

10.1094/pd-75-1133 ◽

1991 ◽

Vol 75 (11) ◽

pp. 1133 ◽

Cited By ~ 24

Author(s):

J. C. Mertely

Keyword(s):

Root Rot ◽

Decline Disease ◽

Vine Decline

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Effect of grafting on resistance to vine decline disease, yield and fruit quality in muskmelon cv. Sawadi

Journal of Agricultural and Marine Sciences [JAMS] ◽

10.24200/jams.vol23iss1pp2-10 ◽

2019 ◽

Vol 23 (1) ◽

pp. 2

Author(s):

Qais Al-Mawaali ◽

Abdullah M Al-Sadi ◽

Fahad A Al-Said ◽

Mohammed Shafiur Rahman ◽

Intisar Al-Zakwani ◽

...

Keyword(s):

Field Experiments ◽

Consumer Preference ◽

Fruit Shape ◽

Consumer Acceptance ◽

High Yield ◽

Farming Community ◽

Yield Production ◽

Decline Disease ◽

Vine Decline ◽

Graft Success

A study was conducted to evaluate graft success, resistance to vine decline disease and effect of grafting on quality and yield of muskmelon. Two field experiments, conducted in Oman, showed that muskmelon cv. Sawadi grafted on six cucurbit rootstocks gave high grafting success: 97.6-99.1% (avg. 98.6%) and 92.4-96.9% (avg. 95.3%) under field conditions in fall 2012 and spring 2013 respectively. No significant differences were observed between seasons among the six treatments and a non-grafted control in consumer preference for odor and firmness, fruit shape, flesh vitamin C, micronutrient content and TSS (sucrose %) or pH in spring 2013 (P > 0.05). The concentration of phosphorus and sodium significantly decreased in both seasons in all treatments in comparison to the control (P > 0.05). In both seasons potassium content significantly increased when Rsscih7458 and Mubyeongjangsoo rootstocks were used (P < 0.05). Strong Tosa rootstocks showed zero graft failure, high resistance to vine decline disease, high yield production and higher TSS (sucrose %) as compared to other rootstocks. Strong Tosa and Tetsukabuto rootstocks showed significantly higher consumer acceptance for rind color, flesh color and overall consumer acceptance in spring 2013 and was also less affected by seasonal changes. Results suggested that by grafting muskmelon cv. Sawadi some quality attributes may be improved in addition to the increased level of resistance to disease. However, additional trials are required to make final recommendations for the farming community.

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DISTRIBUTION OF MONOSPORASCUS ROOT ROT AND VINE DECLINE DISEASE OF CUCURBITS IN EGYPT

Journal of Plant Protection and Pathology ◽

10.21608/jppp.2009.208762 ◽

2009 ◽

Vol 34 (6) ◽

pp. 6811-6821

Author(s):

S. El-Desouky, ◽

M. Awad ◽

Majdah Al-Tuwaijri

Keyword(s):

Root Rot ◽

Decline Disease ◽

Vine Decline

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Effects of Lethal Bronzing Disease, Palm Height, and Temperature on Abundance and Monitoring of Haplaxius crudus

Insects ◽

10.3390/insects11110748 ◽

2020 ◽

Vol 11 (11) ◽

pp. 748

Author(s):

De-Fen Mou ◽

Chih-Chung Lee ◽

Philip G. Hahn ◽

Noemi Soto ◽

Alessandra R. Humphries ◽

...

Keyword(s):

Seasonal Variation ◽

Disease Management ◽

Low Temperature ◽

Feeding Preference ◽

Pathogen Transmission ◽

Interactive Effects ◽

Insect Vector ◽

Cumulative Number ◽

Sticky Traps ◽

And Behavior

Insect vector feeding preference and behavior play important roles in pathogen transmission, especially for pathogens that solely rely on insect vector transmission. This study aims to examine the effects of the 16SrIV-D phytoplasma, the causal agent of lethal bronzing (LB) disease of palms, on associated auchenorrhynchan insects. The numbers of auchenorrhynchans collected during weekly surveys during a yearlong study using yellow sticky traps were analyzed. The cumulative number of H. crudus was 4.5 times greater on phytoplasma-infected relative to non-infected palms. Other auchenorrhynchans showed no difference between phytoplasma-infected and non-infected palms or were greater on non-infected rather than on infected palms. Furthermore, we examined the effects of LB, palm height, temperature, and the interactive effects of these factors on H. crudus abundance. When the palms were infected with LB, at low temperature, H. crudus was more abundant on shorter than taller palms; however, H. crudus was more abundant on taller than shorter palms at the median and higher temperatures. These results may indicate that H. crudus prefers LB-infected palms over non-infected palms. The interactive effects of LB, palm heights, and temperature further suggest that vector monitoring and disease management should be optimized according to seasonal variation in temperature.

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Effects of Viruses (SPVD) on Growth and Yield of Sweet Potato

Experimental Agriculture ◽

10.1017/s0014479700010310 ◽

1979 ◽

Vol 15 (3) ◽

pp. 253-256 ◽

Cited By ~ 34

Author(s):

S. K. Hahn

Keyword(s):

Sweet Potato ◽

Ipomoea Batatas ◽

Virus Disease ◽

Severe Disease ◽

Growth And Yield ◽

Root Yield ◽

Disease Symptoms ◽

Vein Clearing ◽

Chlorophyll Level ◽

Yield Trials

SUMMARYSweet potato (Ipomoea batatas L.) virus disease (SPVD) causes severe disease symptoms of various combinations of leaf strapping, vein-clearing, puckering and stunting. The disease is widespread, especially in Africa, and yield is adversely affected, though there are no figures to quantify this effect nor is it known how yield is affected. Loss of tuberous root yield due to SPVD was studied in sweet potato showing symptoms of the disease. Slips were obtained from plants with and without symptoms and two yield trials in 2 years were conducted by planting them alternately in rows. Yield of fresh tubers was reduced by 78% in plants showing SPVD symptoms but the reduced chlorophyll level of diseased leaves did not appear to affect yield.

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Molecular Dynamics and Mode of Transmission of Koala Retrovirus as It Invades and Spreads through a Wild Queensland Koala Population

Journal of Virology ◽

10.1128/jvi.01871-17 ◽

2017 ◽

Vol 92 (5) ◽

Cited By ~ 11

Author(s):

Bonnie L. Quigley ◽

Vanissa A. Ong ◽

Jonathan Hanger ◽

Peter Timms

Keyword(s):

Envelope Protein ◽

Protein Sequence ◽

Severe Disease ◽

Viral Evolution ◽

Population Level ◽

Infection Prevalence ◽

Infection Level ◽

Phascolarctos Cinereus ◽

Content Type ◽

Mode Of Transmission

ABSTRACT The recent acquisition of a novel retrovirus (KoRV) by koalas ( Phascolarctos cinereus ) has created new opportunities for retroviral research and new challenges for koala conservation. There are currently two major subtypes of KoRV: KoRV-A, which is believed to be endogenous only in koalas from the northern part of Australia, and KoRV-B, which appears to be exogenous. Understanding and management of these subtypes require population level studies of their prevalence and diversity, especially when coinfected in the same population, and investigations of their modes of transmission in the wild. Toward this end, we studied a wild Queensland koala population of 290 animals over a 5-year period and investigated the prevalence, diversity and mode of transmission of KoRV-A and KoRV-B. We found KoRV-A to have an infection level of 100% in the population, with all animals sharing the same dominant envelope protein sequence. In contrast, the KoRV-B infection prevalence was only 24%, with 21 different envelope protein sequence variants found in the 83 KoRV-B-positive animals. Linked to severe disease outcomes, a significant association between KoRV-B positivity and both chlamydial disease and neoplasia was found in the population. Transmission of KoRV-B was found at a rate of 3% via adult-to-adult contact per year, while there was a 100% rate of KoRV-B-positive mothers transmitting the virus to their joeys. Collectively, these findings demonstrate KoRV-B as the pathogenic subtype in this wild koala population and inform future intervention strategies with subtype variation and transmission data. IMPORTANCE KoRV represents a unique opportunity to study a relatively young retrovirus as it goes through its molecular evolution in both an endogenous form and a more recently evolved exogenous form. The endogenous form, KoRV-A, now appears to have stably and completely established itself in Northern Australian koala populations and is progressing south. Conversely, the exogenous form, KoRV-B, is undergoing continuous mutation and spread in the north and, as yet, has not reached all southern koala populations. We can now link KoRV-B to neoplasia and chlamydial disease in both wild and captive koalas, making it an imminent threat to this already vulnerable species. This work represents the largest study of koalas in a wild population with respect to KoRV-A/KoRV-B-infected/coinfected animals and the linkage of this infection to chlamydial disease, neoplasia, viral evolution, and spread.

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The Ecology and Evolution of Japanese Encephalitis Virus

Pathogens ◽

10.3390/pathogens10121534 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1534

Author(s):

Peter Mulvey ◽

Veasna Duong ◽

Sebastien Boyer ◽

Graham Burgess ◽

David T. Williams ◽

...

Keyword(s):

Japanese Encephalitis Virus ◽

Japanese Encephalitis ◽

Severe Disease ◽

Domestic Animals ◽

Encephalitis Virus ◽

Human Populations ◽

Natural Reservoir ◽

Risk Areas ◽

Geographical Expansion ◽

The Western Pacific

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by Culex mosquitoes that currently has a geographic distribution across most of Southeast Asia and the Western Pacific. Infection with JEV can cause Japanese encephalitis (JE), a severe disease with a high mortality rate, which also results in ongoing sequalae in many survivors. The natural reservoir of JEV is ardeid wading birds, such as egrets and herons, but pigs commonly play an important role as an amplifying host during outbreaks in human populations. Other domestic animals and wildlife have been detected as hosts for JEV, but their role in the ecology and epidemiology of JEV is uncertain. Safe and effective JEV vaccines are available, but unfortunately, their use remains low in most endemic countries where they are most needed. Increased surveillance and diagnosis of JE is required as climate change and social disruption are likely to facilitate further geographical expansion of Culex vectors and JE risk areas.

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Comparison of Fusarium solani and F. oxysporum as Causal Agents of Fruit Rot and Root Rot of Muskmelon

HortScience ◽

10.21273/hortsci.28.12.1174 ◽

1993 ◽

Vol 28 (12) ◽

pp. 1174-1177 ◽

Cited By ~ 17

Author(s):

E.R. Champaco ◽

R.D. Martyn ◽

M.E. Miller

Keyword(s):

Fusarium Wilt ◽

Fusarium Solani ◽

Root Rot ◽

Fruit Rot ◽

Breeding Line ◽

Foot Rot ◽

Race 1 ◽

Decline Disease ◽

Vine Decline

Rotting muskmelon fruits commonly are associated with commercial fields that are affected by the root rot/vine decline disease syndrome found in southern Texas. Four isolates of Fusarium solani previously shown to be either weakly pathogenic or nonpathogenic to muskmelon seedlings caused extensive rot on mechanically wounded muskmelon fruits. Two of these isolates caused more extensive fruit rot than either F. solani (Mart.) Sacc. f. sp. cucurbitae W.C. Snyder & H.N. Hans. or F. oxysporum Schlechtend.:Fr. melonis (Leach & Currence) W.C. Snyder & H.N. Hans., causal agents of fusarium crown and foot rot of cucurbits and fusarium wilt of muskmelon, respectively. In other tests, root-dip inoculation of seedlings showed that all muskmelon cultigens included in this study and the breeding line MR-1 were susceptible to a California and an Arkansas strain of F. s. f. sp. cucurbitae race 1.

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