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Thái Bình: Gần 18.000ha lúa nhiễm bệnh lùn sọc đen

Ban Thời sựThứ hai, ngày 02/10/2017 08:40 GMT+7

Ảnh minh họa

VTV.vn – Tỉnh Thái Bình hiện đã ghi nhận gần 18.000ha lúa mùa nhiễm bệnh lùn sọc đen.

  •  Từ cuối tháng 7, hiện tượng lúa lùn lụi đã xuất hiện rải rác ở nhiều đồng nhưng các cán bộ chuyên môn và bà con nông dân cho rằng lúa bị nghẹt rễ do ngộ độc hữu cơ nên chỉ tập trung xử lý bệnh lý này.

Đến khi phát hiện bệnh lùn sọc đen diện tích lúa bị nhiễm đã rất lớn. Hiện nay, việc xử lý nhổ bỏ, tiêu hủy những khóm lúa bị bệnh nặng đang là vấn đề lớn đối với bà con nông dân.

Bệnh lùn sọc đen trên lúa bùng phát ở Quảng Trị Bệnh lùn sọc đen trên lúa bùng phát ở Quảng Trị

VTV.vn – Bệnh rầy lưng trắng trên lúa, bệnh bạc lá, đặc biệt là bệnh lùn sọc đen đang bùng phát mạnh tại Quảng Trị.

* Mời quý độc giả theo dõi các chương trình đã phát sóng của Đài Truyền hình Việt Nam trên TV Online!

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SE farm press

 

crumplevirus UGA CAES
Cucurbit leaf crumple virus, a disease carried by whiteflies, infects vegetable plants like squash.

Whitefly influx puts hurt on Georgia vegetables

High populations of whiteflies over the past few years had a tremendous impact on Georgia’s vegetable crops in both the spring and the fall.

Julie Jernigan | Oct 03, 2017

Summer may have ended, but Georgia’s silverleaf whitefly infestation has not.

Timothy Coolong, University of Georgia Cooperative Extension vegetable specialist, researches whitefly management in an effort to prevent the pest from infecting Georgia’s vegetable crops with viral diseases, like cucurbit leaf crumple virus and tomato yellow leaf curl virus.

Whiteflies are found on vegetable plants, like yellow squash, zucchini and green beans. Last fall, Georgia vegetable growers lost 40 to 50 percent of their yellow squash production. Green bean growers saw similar production losses due to the cucurbit leaf crumple virus, a disease carried by whiteflies.

Also known as “Aleyrodidae,” whiteflies are tiny, winged insects often found on the underside of leaves. They leave behind a tacky substance called “honeydew” that prevents plants from carrying out photosynthesis and causes fungal infections.Coolong and other scientists on the team tested several treatments on yellow squash and zucchini in an attempt to make the plants grow fast enough to tolerate the virus, which might prevent whiteflies from swarming. One application focuses on high fertilizer rates and another uses gibberellic acid to promote foliar development early in the growing process.

“Researching different control methods for whiteflies is important, not only because of the direct damage they can do to crops, but to stop the viruses that they can spread,” Coolong said.

Early control is key to prevention of the viruses spread by whiteflies. Farmers must proceed with caution in working on some of the most susceptible crops because of the losses that have been sustained the past two years, according to Coolong.

“Squash alone is close to a $60 million industry (in Georgia). We suffered significant losses in the fall of 2016 and are seeing losses again this fall. Growers need to have a plan for management before the seed emerges or a plant comes out of the greenhouse,” Coolong said. “Whiteflies can be very devastating.”

Whiteflies thrive in warm, humid climates, and they reproduce quickly. The warmer-than-normal winter that Georgia experienced last year helped whitefly populations multiply. In normal years, Coolong recommends using insecticides as a management tool. Given the current conditions in Georgia, he warns growers that they may not completely wipe out the whitefly population with insecticides alone.

“In a normal year, insecticides would be very effective, but this year the whitefly population is high,” Coolong said. “Even if a product works and kills 90 percent of the population in a field, they will return because of how fast they can reproduce, and all the plants surrounding those fields serve as hosts for the whitefly.”

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FTF logo

Field days show Ugandan farmers hope in disease-resistant varieties

By Allison Floyd
University of Georgia, Peanut & Mycotoxin Innovation Lab

Planting an unimproved variety of peanut in Uganda was a recipe for disaster this year. Groundnut rosette disease (GRD), an aphid-borne virus that causes mottling and affects much of sub-Saharan Africa, took 80% to 100% of the yield in some fields planted with a traditional variety.

The difficult season made farmers even more interested in two recent field-day events held in Uganda, where they could see the results coming from fields planted with improved varieties resistant to GRD.

Farmers check out peanut-growing guides at one of two recent Field Day trainings in Uganda.

One woman, a farmer named Adong Christine borrowed $7,000 from a bank and planted 20 acres with a local variety. At the end of the season, she harvested just two bags of peanuts (from a potential 400 bags) and could not repay the loan.

“There had been an outcry of big losses as most of the capital were borrowed from loan institutions. This event showcasing improved groundnut varieties therefore was timely as it restored hopes and enhanced adoption,” organizers said.

David Okello, the head of Uganda’s national groundnut research program and a leading scientist on PMIL’s breeding project, is behind many of the varieties. Based at the National Semi-Arid Resources Research Institute (NaSARRI) in Serere District, Okello works to create varieties that are high yielding, resistant to drought and GRD, and to educate farmers about practices that will give them more success with their peanut crop.

Peanuts are a traditional crop in Uganda and much of sub-Saharan Africa, are high-protein and valuable as a cash crop. Still, GRD is a persistent problem that stunts the growth of otherwise healthy plants and can destroy a crop if the disease strikes early enough in the season before flowering.

A woman farmer picks up some bags of seed at Field Days in the Nwoya District of Uganda. At the end of a particularly bad season for disease, many farmers made the investment to buy small bags of improved seed.

At one of two field days, 61 farmers, researchers and representatives of local government visited a 5.6-acre plot planted with three varieties bred for their resistance to GRD and leaf-spot, Serenut 9T (Aber), Serenut 14R and Serenut 5R. While participants could see for themselves the success of the varieties, farmers in the Loyo Kwo group, who are using the new varieties, explained their agronomic practices, where they get seed and how NaSARRI trainings helped improve their results.

“Heart breaking and sad testimonies came from the farmers growing local varieties,” Okello said. “The Loyo Kwo group members, on the other hand, were boasting of bumper harvests, higher income and improved livelihoods that they are experiencing from adopting the improved groundnut varieties,” Okello  said

Uganda Field DaysLeoora Okidi (centre) shows her approval of the high yield of Serenut 11T, an improved variety during a Field Day in August 2017 in the Kiteny Pader District of Uganda.

 

Farmers were able to buy small packs of .5 kg to 3 kg., and the NaSARRI team delivered 45 kgs of Serenut 8R (Achieng), a large-seeded red variety that had been previously promised.

In a second field day, farmers spent part of a religious holiday – the Assumption of the Virgin Mary to Heaven – visiting test plots, learning about improved production practices and visiting a farm where the owner planted Serenut 5R and Serenut 11T alongside the local Red Beauty variety.

Uganda Field Days crowdA crowd of farmers fan out over a field at a recent Field Days event comparing the yield and disease resistance of improved lines and varieties over the traditional, unimproved types, which have been ravaged by rosette disease this year.

 

The farmer, Leonora Okidi, planted 2 of her 5 acres with an improved variety, and the other 3 acres with the local variety. She abandoned the local variety after the first weeding since most of the plants had been severely attacked by the rosette virus.

In a good year, she is able to feed and educate her 11 own children and support 25 others from her groundnut operation, which is part of a women-led group called Pur Lonyo or “Farming is Wealth,” she said.

Okidi first connected with Okello through her son, who he mentored in his diploma and bachelor’s degree studies and still supervises in his current master’s degree studies. She offered land to host demonstration plots and participatory variety trials and co-funded the operations using her family labour.

“The superiority of our improved lines and varieties over her local varieties caught her attention and (Okidi) quickly adopted these improved varieties and has become a model research farmer in the village,” Okello said. “Through this effort our improved varieties adoption rates has increased and we are closely working with her women group to upscale these successes, improve their livelihoods and increase varieties adoption.”

– Published Sept. 1, 2017

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sd-logo

Date: July 18, 2017
Source: eLife
Summary:
Researchers have discovered how a severe rice virus reproduces inside the small brown planthopper, a major carrier of the virus.
FULL STORY

A small brown planthopper — a member of a species known for being a major carrier of rice stripe virus — feeding on a rice plant.
Credit: Junjie Zhu

Researchers from the Chinese Academy of Sciences’ Institute of Zoology have discovered how a severe rice virus reproduces inside the small brown planthopper, a major carrier of the virus.

“Most plant viruses depend on insects to carry them between plants, and many can reproduce inside the cells of these carrier insects, or ‘vectors’, without actually harming them,” says Feng Cui, Professor of Zoology. “RSV, one of the most notorious plant viruses, is carried by the small brown planthopper and, once inside the cells, manages to achieve a balance with the insect’s immune system.”

Viral infections in animal hosts activate a pathway by which a type of enzyme, called c-Jun N-terminal kinase (JNK), is signalled to respond. But how exactly viruses regulate this pathway in vectors remains an open question, and Cui says the answer would provide important clues for intervening in the spread of plant viruses.

To address this question, Cui and her team explored the effect of RSV on the JNK signalling pathway in the small brown planthopper. Studying interactions between proteins, and using an analytical method to determine the compounds that are important for the JNK signalling pathway, they found that the virus activates the pathway in various ways — especially through the interaction of a planthopper protein called G protein pathway suppressor 2 (GPS2), and a viral protein called capsid protein.

“The interaction between these two proteins promotes RSV reproduction inside the planthopper, ultimately leading to disease outbreak when the insect carries the virus among rice crops,” says first author and postdoctoral researcher Wei Wang.

“We discovered that RSV infection increased the level of another protein called Tumor Necrosis Factor-α (TNF-α) and decreased the level of GPS2 in the insect vector. The virus capsid, which stores all of RSV’s genetic material, competitively binds GPS2 to stop it from inhibiting the JNK activation machinery. JNK activation then promotes RSV replication in the vector, while inhibiting this pathway causes a significant reduction in virus production, therefore delaying disease outbreak in plants.”

The findings suggest that inhibiting the JNK pathway, either by lowering JNK expressions, strengthening interactions with GPS2 or weakening the effects of TNF-a, could be beneficial for rice agriculture.

“Such inhibition could be achieved through breeding or other means of genetic modification,” Wang concludes. “In some cases, it could be possible to administer the appropriate chemical compounds to rice plants to reduce the spread of RSV.”


Story Source:

Materials provided by eLifeyvtxvtcywxufvr. Note: Content may be edited for style and length.


Journal Reference:

  1. Wei Wang, Wan Zhao, Jing Li, Lan Luo, Le Kang, Feng Cui. The c-Jun N-terminal kinase pathway of a vector insect is activated by virus capsid protein and promotes viral replication. eLife, 2017; 6 DOI: 10.7554/eLife.26591

 

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From Pestnet

USDA releases proposals to fight citrus greening & diamondback moths

In the past two weeks, USDA’s Animal and Plant Health Inspection Service (APHIS) has released documents on proposals to release two genetically modified (GM) organisms: diamondback moths and a virus designed to control the citrus greening disease attacking the citrus industry.

DB moth

Diamondback moths are a global pest of cruciferous crops such as broccoli, Brussel sprouts and cabbage. On April 18, the USDA released a draft environmental assessment of a proposed experiment by a Cornell entomologist with GM diamondback moths.

The scientist, Anthony Shelton, plans to release tens of thousands of GM moths into a 10-acre vegetable field to test their potential as an “insecticide-free” control option for diamondback moths. The GM moths have been engineered to repress female survival, known as a “female autocidal trait.”

You can read the full assessment which concludes it will have no harmful effects here.

Citrus Greening
A Florida nursery, Southern Gardens Citrus Nursery, is proposing the release of a GM virus, Citrus tristeza virus, which has been engineered to express bacteria-fighting proteins found in spinach. The GM virus, which has been undergoing controlled field tests since 2010, would be grafted — not sprayed — onto citrus trees in Florida. USDA has announced its intent to launch an environmental impact statement on Southern Garden’s proposal.

source: dtnpf.com

Publication date: 4/25/2017

Diamondback moths are a global pest of cruciferous crops such as broccoli, Brussel sprouts and cabbage. On April 18, the USDA released a draft environmental assessment of a proposed experiment by a Cornell entomologist with GM diamondback moths.

The scientist, Anthony Shelton, plans to release tens of thousands of GM moths into a 10-acre vegetable field to test their potential as an “insecticide-free” control option for diamondback moths. The GM moths have been engineered to repress female survival, known as a “female autocidal trait.”

You can read the full assessment which concludes it will have no harmful effects here.

Citrus Greening
A Florida nursery, Southern Gardens Citrus Nursery, is proposing the release of a GM virus, Citrus tristeza virus, which has been engineered to express bacteria-fighting proteins found in spinach. The GM virus, which has been undergoing controlled field tests since 2010, would be grafted — not sprayed — onto citrus trees in Florida. USDA has announced its intent to launch an environmental impact statement on Southern Garden’s proposal.

source: dtnpf.com

Publication date: 4/25/2017

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Cucumber green mottle mosaic virus could have entered Queensland through imported seeds – ABC News (Australian Broadcasting Corporation)

//4654321.fls.doubleclick.net/activityi;src=4654321;type=abcne0;cat=abcne000;ord=4463444923102;~oref=http%3A%2F%2Fwww.abc.net.au%2Fnews%2F2017-05-04%2Fcucumber-green-mottle-mosaic-virus-imported-seed-biosecurity-qld%2F8494354?

Ccucumber green mottle virus could have entered Queensland through imported seeds

 

Posted 3 May 2017, 3:18pmWed 3 May 2017, 3:18pm

Biosecurity authorities are trying to figure out how a fruit and vegetable rotting disease broke out in Queensland, but have initial suspicions it was through imported seed.

Farmers from the Bundaberg region are angry cucumber green mottle mosaic virus (CGMMV) has recently been discovered on five local properties, owned by two growers.

CGMMV causes internal rot and discolouration in some cucurbit family fruit and vegetables, and its discovery comes months after an outbreak of white spot disease decimated the aquaculture industry in south-east Queensland.

Biosecurity Queensland spokesman Mike Ashton said the virus was not harmful to humans, but could ravage parts of the agriculture industry if a widespread outbreak occurs.

He said there was a possibility the virus was brought onto the infected farms by imported seeds.

That is considering the businesses operate independently and do not share personnel and equipment.

“That kind of increases the risk that perhaps it was seed that was the source of the introduction,” he said.

“It’s highly unlikely that we’ll ever be able to pinpoint exactly how it got introduced.”

“We’re certainly doing tracing investigations to try and identify the source.”

Farmers like Gino Marcon are angry there has been an outbreak of another virus, and are switching to less risky crops.

Mr Marcon normally grows a wide range of vegetables on his farm, but this year, he is only growing tomatoes to avoid CGMMV.

“We’ve actually stopped growing cucumbers, we’ve sort of got a wait-and-see attitude at the moment,” Mr Marcon said.

“We’re a bit worried that the disease may affect our zucchini production, so we’ve switched over to 100 per cent tomato production in our greenhouses.”

He blamed biosecurity authorities for the outbreak.

“We’ve lost confidence in the system and that’s the biosecurity system,” Mr Marcon said.

“We think it’s not broken, it’s shredded to bits. It’s simply not working.

“I think the whole system needs to be overhauled, we’re not getting value for money for the money being allocated to biosecurity.

“[Politicians] need to look long and hard at the whole system and change it.”

Mr Ashton rejects the allegation that the system has failed.

“We have managed to restrict the disease to a very small number of properties in Queensland,” he said.

“Unlike the Northern Territory and increasingly so in Western Australia where the disease has become quite established.”

There have been previous outbreaks of CGMMV in the Territory and WA, and an isolated case at Charters Towers in North Queensland in 2015.

Biosecurity Queensland hope the Charters Towers farm will be declared clear of the virus later this year.

The Federal Agriculture Department introduced mandatory imported seed testing to try and combat CGMMV in 2014.

In a statement, the department said it uses a sample size more than four times the size (9,400 seeds) than that used internationally (2,000).

It said that gave a high level of confidence in the results.

Topics: pest-management, rural, quarantine, crop-harvesting, agricultural-policy, vegetables, activism-and-lobbying, agricultural-crops, fruit, fruits, bundaberg-4670, qld

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From PestNet/www.pestnet.org/Grahame Jackson

PhysOrg

https://phys.org/news/2017-05-four-billion-year-old-fossil-protein-resurrected-bacteria.html

 

old virus

This figure shows two possible outcomes from a viral attempt to infect the cell. On the left, the virus binds to the bacterium, injects its genetic info, and stops because it can’t recruit the needed proteins. On the right, the virus binds to the cell, injects the genetic info, recruits the proteins, and starts replicating, resulting in the cell bursting and releasing more viruses. Credit: Jose Sanchez-Ruiz

Read more at: https://phys.org/news/2017-05-four-billion-year-old-fossil-protein-resurrected-bacteria.html#jCp

 

In a proof-of-concept experiment, a 4-billion-year-old protein engineered into modern E. coli protected the bacteria from being hijacked by a bacteria-infecting virus. It was as if the E. coli had suddenly gone analogue, but the phage only knew how to hack digital. The ancient protein, an ancestral form of thioredoxin, was similar enough to its present-day analogues that it could function in E. coli but different enough that the bacteriophage couldn’t use the protein to its advantage. The work, which could be useful in plant bioengineering, appears May 9 in Cell 

“This is an arms race. Thioredoxin has been changing in evolution to avoid being hijacked by the virus, and the virus has been evolving to hijack the protein,” says senior author Jose Sanchez-Ruiz of the University of Granada in Spain. “So we go back, and we spoil all of the virus’ strategy.”

Sanchez-Ruiz’s lab specializes in reconstructing ancient gene sequences that code for proteins. Since proteins do not preserve for billions of years, the researchers make their best estimation of the ancient protein based on genetic data across many different taxa. Thioredoxin, a versatile work-horse protein that moves electrons around so that chemical reactions in the cell can occur, is a favorite in the lab because it has been around almost since the origin of life and it is present in all modern organisms. We can’t live without it, nor can E. coli.

Thioredoxin also happens to be one of the proteins that bacteriophage must recruit to survive and replicate. Without a hijack-able thioredoxin, the virus hits a dead end. In a series of experiments led by Asunción Delgado, then a post-doc at the University of Granada, the researchers tested seven reconstructions of primordial thioredoxins, ranging in age from 1.5 billion years old to 4 billion years, to see if they could function in modern E. coli.

The old-school thioredoxins passed the test with varying degrees of success. “That was a bit surprising,” says Delgado. “The modern organism is a completely different cellular environment. Ancestral thioredoxins had different molecular partners, different everything. The farther back we get from present, the less they work in a modern organism. But even when we get back to close to the origin of life, they still show some functionality.”

But the ancestral thioredoxins were just different enough that the modern phage couldn’t recognize or bind to them.

However, resurrecting ancient proteins may be useful as more than a scientific curiosity. Virologists tend to focus on the human-infecting ones, but the viruses that kill the most people are not human pathogens but rather the viruses that kill off crops, sparking famines and mass starvation. Delgado, Sanchez-Ruiz, and their colleagues speculate that ancient proteins could be edited into plants to confer protection against crop-killing viruses. However, this idea has yet to be tested in plants.

“If this is applied to plants, it wouldn’t be genes from ancient bacteria; it would be genes from the same plant. It would be the ancestral version of a gene from the same plant,” says Sanchez-Ruiz. “This is genetic alteration, of course, but it is a mild genetic alteration. This is not like having a gene from one species being transferred to a different species. Also, this would not be like Jurassic Park. It would just be a comparatively small change in a gene that the plant already has.”

Protein resurrection experiments could also shed light on how evolution works at the protein level. “What we can do is let the virus evolve to adapt to the ancestral protein, and then do the experiment in reverse,” says Sanchez-Ruiz. “Once it’s adapted to the ancestral protein, we can test how it reacts to the modern protein. We can see if it repeats the evolution. So it would be kind of a molecular version of this Stephen J. Gould ‘replaying the tape of life’ idea.”

The researchers’ next set of experiments will focus on the fundamentals of protein evolution, but they point out that understanding and resurrecting old proteins could be a key resource for biotech. Instead of introducing new elements, bioengineers may be able to re-use older ones from earlier in viruses and cells’ co-evolutionary history. “Some people think that evolution is just a theory or is just some kind of philosophic explanation,” says Sanchez-Ruiz. “Evolutionary studies have practical applications.”

Explore further: ‘Digging up’ 4-billion-year-old fossil protein structures to reveal how they evolved

More information: Cell Reports, Delgado et al.: “Using Resurrected Ancestral Proviral Proteins to Engineer Virus Resistance” http://www.cell.com/cell-reports/fulltext/S2211-1247(17)30531-4DOI: 10.1016/j.celrep.2017.04.037

Journal reference: Cell Reports

Provided by: Cell Press

Read more at: https://phys.org/news/2017-05-four-billion-year-old-fossil-protein-resurrected-bacteria.html#jCp

 

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