Symptoms Pathogen Disease Control and Prevention of TMV - Tobacco mosaic virus introduction
Tobacco mosaic virus (TMV), also translated as tobacco mosaic
virus, is a single-stranded RNA virus that specifically infects plants,
especially tobacco and other solanaceous plants, which can make these infected
leaves look like Mottled and stained, hence the name (mosaic is mosaic, meaning
collage). At the end of the 19th century, people were known to have certain
diseases that threatened the survival of tobacco crops, but it was not until
1930 that the existence of this virus was known. It is the pathogen of tobacco
mosaic disease and belongs to the Tobamovirus group.
Tobacco mosaic disease and tomato mosaic disease have long
been known. Mosaic symptoms appear on the leaves, the growth is in a bad state,
and the leaves are often deformed.
In 1883, German
scientist Adolf Mayer discovered that tobacco mosaic disease can be transferred
by extracting the juice of infected leaves and applying it to healthy leaves.
After failing to find
disease-causing microorganisms in the juice, Mayer believes that the
disease-causing microorganism is a very small bacteria that is not visible
under the microscope.
I.
Iwanowski
(D.I. Iwanowski) first proved it in 1892 The disease was caused by a filtering
pathogen, but Ivanovsky insisted that filterable bacteria or toxins secreted it
caused tobacco mosaic disease.
II.
in
1897, Dutch botanist Bayerinck (Martinus Beijerinck) A series of classic
experiments confirmed that the source of infection in the filtrate can be
replicated.
In fact, the pathogen only replicates in the host it infects.
In a
more in-depth experiment, Bayerinck discovered that this pathogen is not like
bacteria that can be cultivated in test tubes or petri dishes with nutrients.
He pretends that this is a reproducible particle that is smaller and simpler
than bacteria.
Bayerinck is therefore recognized as the first scientist to
propose the concept of virus.
III.
In
1935, Bayeklin's guess was confirmed by Stanley (W.M. Stanley), who believed that
the pathogen was a protein and first isolated virus-like crystals from the
juice of the diseased leaves in 1935.
It was learned that this protein also
contains nucleic acids And sure that the pathogen is this virus.
The virus is
extremely stable, because it can multiply in a large number of diseased leaves,
so 2 grams of crystals can be purified from 1 liter of juice extracted from
diseased leaves. The viral plasmid is a rod-shaped body with a length of 300 nm
and a diameter of 15 nm. It has a single-stranded (+) RNA with a molecular
weight of 2 × 106 Daltons.
The nucleic acid is surrounded by 2130 protein
subunits with a molecular weight of 17530 Daltons.
The host range as a pathogen
is very wide, and it is now known to be parasitic to 198 plants in 22 families
of monocotyledons.
What are the Symptoms of Tobacco Mosaic Virus?
When tobacco mosaic virus infects tobacco plants, it will
destroy the tissue structure of the plants, and the most damaging to the young
leaves will make the young leaves appear.
What is the Symptom of Open Veins due to Tobacco mosaic virus?
Symptoms of open veins, that is, translucent phenomena appear
in the lateral and branch veins of the leaf.
Tobacco mosaic virus multiplies in
tobacco cells. Viral RNA will seriously affect the normal division of tobacco
cells, resulting in malformation and fission of tobacco mesophyll cells.
Propagation or suppression, the symptoms of uneven leaf
thickness, spots appear on the leaves, showing different areas of yellow and
green, with the further infection of mosaic virus, gradually lead to necrosis
of the leaf tissue.
Tobacco leaves have a large area of brown necrosis spots,
the shape of the leaves is twisted and shrunk.
This phenomenon is especially
obvious on the old leaves, the serious diseased leaves are raised to form
bubbles, and the edges are curved inward.
Early-onset tobacco plants are severely dwarfed. Tobacco
plants do not grow normally. They do not bloom normally during maturity. They
have poor resistance and are easily disturbed by the outside world.
The leaves
and flowers and fruits are easy to fall off. The amount of seeds is small and
generally not normal. Sprouts grow.
This virus may also affect other types of plants.
 |
| Tobacco Mosaic Virus on Tomato Plant |
What is Tobacco mosaic virus Pathogen?
Tobacco mosaic virus (TMV) is a virus disease.
As many as 350 species, the virus particles are straight
rod-shaped, 300 nm × 18 nm in size, with strong pathogenicity and stress
resistance.
The virus can survive for 52 years in dried tobacco leaves.
Has infectious activity.
The passivation temperature is 90-93 ℃ for 10 minutes, the dilution limit is 1000000
times, and the in vitro drug retention period is 72-96 hours.
It has been pathogenic for several
years under sterile conditions, and has survived for more than 30 years in
xerotic tissues.
There are different strains of the virus. There are four
strains in China: common strains, tomato strains, macular strains and bead
spots.
The diversity of symptoms due to differences in pathogenicity and
compound infection with other viruses.
What is the Tobacco mosaic virus transmission route?
TMV can overwinter on a variety of plants. The primary source
of infection is disease-carrying debris and other host plants.
In addition,
under-decomposed poisonous fertilizers can also cause initial infection. Spread
mainly through juice. Slightly rubbing the diseased leaves to cause micro
wounds, the virus can invade, not from the large wounds and self.
Then the orifice intruded. After invasion, they propagate in
the parenchyma cells, and then enter the vascular bundle tissue to infect the
whole plant.
Under the condition of 22-28 ℃, the infected plants begin to show symptoms after
7-14 days.
The field is reinfested by rubbing diseased seedlings with
healthy seedlings or agricultural operations.
In addition, locusts, tobacco insects and other insects in
chewing mouthparts in tobacco fields can also spread TMV virus.
The appropriate
temperature for TMV to occur is 25-27 ° C, invasion above 38-40 ° C is
inhibited, and symptoms above 27 ° C or below 10 ° C disappear.
What is the Pathogenesis of Tobacco mosaic virus?
Tobacco common mosaic virus disease is one of the main
diseases of tobacco.
It is widely distributed in the majority of tobacco areas
in China, especially in the southern tobacco area.
It is more common and
increasingly worse.
The general incidence rate is 5% -20%, which often causes
severe dwarfing of plants.
The loss can reach more than 50%, seriously harming
the yield and quality of tobacco leaves, and causing huge economic losses to
the tobacco industry.
Tobacco common mosaic disease is the most susceptible disease
in the tobacco seedling stage and the early stage of field growth, mainly
occurring from the seedling bed stage to the field bud stage. Temperature and
light greatly affect the spread and epidemic speed of the disease.
What is Tobacco mosaic disease?
Strong light can shorten the incubation period. Continuous
cropping or interplanting with Solanaceae crops increased the source of poison,
and the incidence and degree of incidence increased significantly.
Unhygienic
cultivation is an important cause of epidemic.
Touching between sick and
healthy plants, applying unrotted organic fertilizer, and cultivating the soil
with virus can increase the virus infection. The soil is hardened, the climate
is arid, and plots with severe nematodes in the field are seriously ill.
What is the situation of Tobacco mosaic virus in Tobacco Growing Countries?
China has a long history of tobacco production, and tobacco
is one of the important economic crops in China.
Tobacco virus disease is an important
type of disease on tobacco.
Tobacco virus disease is widespread, widely distributed, and
serious in tobacco cultivation areas around the world.
It seriously affects the
yield and quality of tobacco.
Up to now, 47 viruses have been found to infect tobacco, and
more than 20 are common.
There are 17 tobacco virus diseases found in China.
After the tobacco is infected with the virus, the chlorophyll
is destroyed, the photosynthesis is weakened, the leaf growth is inhibited, the
leaves are small and deformed, which seriously affects the yield and intrinsic
quality.
Tobacco virus disease caused by TMV infection of tobacco is
the most common and most harmful disease in tobacco in China.
The tobacco pest control and innovation team based on nearly
30 years of statistics.
Through whole genome sequencing and Bayesian system
dynamic analysis method, analyzed is the complete sequence of 56 TMV isolates
in 17 tobacco leaf producing areas in China for the first time identified China.
The characteristics of
the spatiotemporal diffusion of TMV on tobacco have found that the two large
group evolutions of TMV in China are concentrated in the mid-1990s and the
beginning of this century.
What is the Tobacco mosaic virus detection method?
In order to reduce and reduce the harm of viruses to the
tobacco industry, the establishment of efficient and sensitive detection
technology is a prerequisite for solving basic problems such as early
identification of disease resistance.
This will help to study the transmission
routes and occurrence rules of viral diseases and formulate prevention and
control for science. The strategy lays the foundation.
What is Monoclonal antibody technology of TMV Detection?
Monoclonal antibody technology was used to obtain
anti-tobacco mosaic virus (TMV) monoclonal antibody, and the rapid development
of tobacco mosaic virus was established through colloidal gold labeling
technology.
Rapid immunochromatography detection technology and SQUID magnetic
quantitative measurement technology detection methods, and developed TMV
colloidal gold rapid detection test paper for qualitative detection and TMV
nano magnetic beads rapid detection test paper for quantitative detection, the
detection sensitivity is 1ng / mL and 0.1 ng / mL, respectively.
The established method is simple in operation, fast in
sensitivity and good in specificity, and is an effective method for on-site
screening of various TMV asymptomatic and diseased tobacco plants in tobacco
seedlings.
What are the Tobacco mosaic virus control measures?
Taking tobacco plants as an object, strengthen the health
cultivation of tobacco plants, cut off the transmission route, highlight
resistance induction, and assist in the prevention and control measures of
chemical agents.
Tobacco mosaic virus selects disease-resistant varieties
Select disease-resistant varieties with strong growth
potential and rapid development, and adapt to local conditions such as Liao 44,
6315, Guanghuang 54, 176, Nc89, G80, 8611, etc. Pay attention to the selection
of high-resistance varieties.
Tobacco mosaic virus prevention before transplantation
Remove the diseased plants and turn over the soil before
winter. Use low temperature conditions such as frost, rain and snow in winter,
and turn over the soil before winter to reduce the source of overwintering
bacteria.
In the spring of the following year, the fine rakes were
turned deeply to ripen the tillage layer, reduce the base of infection, and
create conditions for healthy growth of tobacco.
No intercropping or rotation
with Solanaceae, Cruciferae crops, no serious tobacco plots for at least 2
years.
What is Tobacco mosaic virus seedling control?
At present, no highly resistant varieties that can be widely
promoted have been found. In the seedling stage, the goal is to cultivate disease-free
and strong seedlings, choose appropriate disinfection agents for floating
seedlings, pay attention to the disinfection of the water body of the nursery
pond and the blade cutter, and ensure the supply of nutrients.
Strengthen the
management of seedling stage, smoking is prohibited during the operation, hands
and tools should be disinfected, the greenhouse is managed by a dedicated
person, and the entry of idlers and other people is prohibited.
Tobacco mosaic virus control during transplanting period
Early sowing and early planting can be properly carried out.
Diseased seedlings are removed during transplanting, and seedlings are checked
in time to ensure that the roots of the transplanted seedlings can contact the
soil as much as possible.
Actively promote the open planting technology of small
seedlings to ensure the success of one-time transplanting and avoid
cross-infection of multiple seedlings.
If the weather is dry when transplanting, pay attention to
make up the water to promote the early growth of tobacco seedlings.
What is the Process of Tobacco mosaic virus mass control?
In the early stage of
the disease, it can be sprayed with 22% Jinyebao WP 300 times solution, 1.5%
Phytopathic No. 2 EC 1000 times solution or 2% Ningnanmycin solution 250 times
solution.
For areas where the virus disease is relatively light, attention
should be paid to the addition of trace elements zinc, while the use of
aminooligosaccharins and other induced resistance of tobacco to reduce the loss
of virus disease caused by tobacco leaves.
What is Long-term control procedure of tobacco mosaic virus?
Do a good job of field hygiene management, pay attention to
the regulation of fertilizer and water, and minimize the contact of tools,
clothes, hands, etc. with tobacco leaves during field operations.
What is Tobacco mosaic virus topping stage control?
Note that the diseased plant and the healthy plant are topped
separately. Top the healthy plant first and then the diseased plant. Topping
should be done after the dew dries.
What is Tobacco mosaic virus harvesting period control?
Remove the bottom leaves in time and transport them to the
treatment pond outside the tobacco field for centralized treatment to prevent
the re-infestation caused by the diseased leaves left in the field.
After the tobacco is harvested, the tobacco stalks should be
removed in time and the field should be cleared.
If it is possible to plant
rape, green manure, etc. it will be better and more active to reduce the
presence of pathogens.
Author's Bio
 |
| Dr. Shawna Reason |
Education: MBBS, MD
Occupation: Medical Doctor / Virologist
Specialization: Medical Science, Micro Biology / Virology, Natural Treatment
Experience: 15 Years as a Medical Practitioner
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