Feeds:
Posts
Comments

Archive for the ‘Research’ Category

PhysOrg

Oct 02, 2014

Herbivores (species that eat plants; e.g. caterpillars) consume more non-native (introduced from other places) oak leaf material in areas with diverse native plant communities than in less diverse communities. Why diverse plant communities tend to resist invasion by non-native plants, remains uncertain. Researchers from the Illinois Natural History Survey and the Morton Arboretum have been examining the potential role of herbivores on the invasion of non-native plant species in diverse plant communities.

The researchers examined herbivore damage on leaves of non-native oak trees in arboreta across the United States. They found that non-native oaks in regions with high oak species diversity showed more leaf damage than those in regions with low diversity.

Ian S. Pearse, lead author on the study in the current issue of the Royal Society journal Proceedings of the Royal Society B, says that, “competition for resources has often been thought to limit invasions in diverse plant communities, but herbivory could also limit these invasions.”

While native oaks still suffered more leaf damage than non-native oaks overall, in the absence of native oaks non-native oaks showed even less leaf damage. Pearse conjectures, “Diverse plant communities are more likely to contain herbivores that are able to consume a non-native species, which may help to explain why diverse communities are able to resist invaders while others are easily dominated.”

As the introduction of non-native species increases, protection of intact plant communities and their associated herbivores may become critical to guarding against the non-native species invaders.

Explore further: Plant biodiversity under threat from general viruses
More information: Proc. R. Soc. B 7 November 2014 vol. 281 no. 1794 20141841. Published 17 September 2014. DOI: 10.1098/rspb.2014.1841
Journal reference: Proceedings of the Royal Society B
Read more at: http://phys.org/news/2014-10-herbivores-important-role-habitats-invasive.html#jCp

 

Read Full Post »

ant nectar 1

An ant drinking nectar from an extrafloral nectary on a leaf of Viburnum sargentii at Cornell Plantations. Credit: Ellen Woods

 

PhysOrg
http://phys.org/news/2014-11-insects-diversity-nectar-producing.html
Nov 13, 2014 by Krishna Ramanujan

Some plants form into new species with a little help from their friends, according to Cornell research published Oct. 27 in the Proceedings of the National Academy of Sciences.
The study finds that when plants develop mutually beneficial relationships with animals, mainly insects, those plant families become more diverse by evolving into more species over time.
The researchers conducted a global analysis of all vascular plant families, more than 100 of which have evolved sugary nectar-secreting glands that attract and feed protective animals, such as ants. The study reports that plant groups with nectar glands contain greater numbers of species over time than groups without the glands.
“Why some groups of species evolve to be more diverse than others is one of the great mysteries in biology,” said Anurag Agrawal, professor of ecology and evolutionary biology and co-author of the paper. Marjorie Weber, Ph.D. ’14, formerly of Agrawal’s lab and now a postdoctoral fellow at the University of California, Davis, is lead author.
“By attracting bodyguards to plants, these glands can increase plant success in a variety of habitats by protecting them from local pests,” Weber said. “This in turn may increase plant survival in remote places, decrease risk of local extinction or both.”

Also, when ants, for example, defend plants against pests, the plants may apply the energy and resources that would otherwise have been apportioned to defense to the development of new traits.

ant nectar 2

When plants develop mutually beneficial relationships with insects, those plant families become more diverse. Credit: Ellen Woods

 

These benefits may make these plants more successful at migrating to new places, where they can diversify into new species over time.
Nectar glands have evolved independently more than 100 times over Earth’s history, which gave the researchers many opportunities for analyses of these mechanisms in different plant families.
The analysis “was possible because of the DNA sequence data available for many plant species,” Agrawal said. The researchers used the data for computer modeling of phylogenies (branching diagrams that depict the evolutionary relatedness among groups of organisms), and to calculate numbers of new species that occur per million years.
Biologists have long speculated which traits may have been “key innovations” that have led to highly diverse groups of species, Agrawal said. In animals it has been suspected that flight played a similar key role in the diversification of birds, bats and insects. For plant species, defense against insect pests and the formation of mutually beneficial relationships with predators was a critical evolutionary leap, he said.

Journal reference: Proceedings of the National Academy of Sciences
Provided by Cornell University

Read Full Post »

Bloomberg Businessweek

Businessweek.com

December 8- December 14, 2014, pages 112-113

Anniversary  Issue: 85 Years/Ideas

Green revolution p 1131

Green revolution p 2132

 

 

Read Full Post »

The Secret of Dragonflies’ Flight
By controlling each of their four wings individually, dragonflies can manipulate fluid dynamics to execute a wide range of aerial maneuvers

Released: 14-Nov-2014 8:00 AM EST
Embargo expired: 23-Nov-2014 9:00 PM EST
Source Newsroom: American Physical Society’s Division of Fluid Dynamics

http://www.newswise.com/articles/view/626203/?sc=dwtn

dragonflies image (1)

Jane Wang research group, Cornell University
A collage of dragonflies during recovery flight. Yellow arrows indicate the body orientation, and the circles on the wings are tracked points, overlaid on top of the image.

 

 

 

 

Newswise — WASHINGTON, D.C., November 23, 2014 — Dragonflies can easily right themselves and maneuver tight turns while flying. Each of their four wings is controlled by separate muscles, giving them exquisite control over their flight.
Researchers from Cornell University are investigating the physics behind this ability by recording high-speed video footage of dragonflies in flight and integrating the data into computer models, and they will present their findings at the 67th annual meeting of the American Physical Society (APS) Division of Fluid Dynamics, held Nov. 23-25 in San Francisco.
“Dragonflies tend to have unpredictable flight — that’s what makes them fascinating. They hover for a bit, and every so often they’ll make a quick, sharp turn. They rarely stay right in front of your camera for us to contemplate on,” explained lead researcher Jane Wang.
In collaboration with Anthony Leonardo at Janelia Farm, the research campus of the Howard Hughes Medical Institute, Wang devised a unique experimental method to make dragonflies perform repeatable aerial maneuvers: to attach a tiny magnet to the underside of each insect that allowed them to hang upside down from a metal rod. When the magnet is released, said Wang, “Dragonflies somehow understand the orientation and they do a stereotypical maneuver: they roll their body to make a 180-degree turn.”
By tracking the body and wing orientations using high-speed video recording of this rapid roll in high resolutions, the team uncovered how dragonflies were altering the aerodynamics on their wings to execute the turn.
“The wings on an airplane are oriented at some fixed angle. But insects have freedom to rotate their wings,” explained Wang. By adjusting the wing orientation, dragonflies can change the aerodynamic forces acting on each of their four wings.
The iridescent insects can also change the direction in which they flap their wings — known technically as their “stroke plane.” The new data showed that dragonflies can adjust the stroke plane orientation of each wing independently.
With so many different variables, understanding how dragonflies control their flight is a complicated task. “Our job is to try to find out the key strategies that dragonflies use to turn,” explained Wang. She and her graduate student James Melfi Jr. are incorporating their data into a computer simulation of insects in free flight, which allows them to examine the separate effect of each kinematic change.
Wang described her group’s work as “using physical principles to explain animal behavior.”
“Even though biological organisms are complex, they still obey some basic laws — in this case, fluid dynamics. … I’m hoping to understand how these basic laws influence evolution of insects and the wiring of their neural circuitry.”
The presentation, “Roll Dynamics in a Free Flying Dragonfly,” was presented at 6:15 p.m. PT on Sunday, Nov. 23, 2014 in the Moscone West Convention Center, 2nd Floor Lobby. ABSTRACT: http://meetings.aps.org/Mehttp://meetings.aps.org/Meeting/DFD14/Session/F1.16eting/DFD14/Session/F1.16
###

 

 

 

 

 

Read Full Post »

Wheat streak mosaic KSU(1)

Wheat streak mosaic virus is one of the most damaging and costly diseases wheat producers encounter, but plant pathologists have recently uncovered a way for the wheat plant to defend itself against this particular virus and others.

 

Helping Wheat Defend Itself Against Damaging Viruses

Patent-pending technology has shown success in disease resistance to wheat streak mosaic virus and triticum mosaic virus, among others.

Released: 18-Nov-2014 10:30 AM EST
Source Newsroom: Kansas State University Research and Extension

Newswise — MANHATTAN, Kan. – Wheat diseases caused by a host of viruses that might include wheat streak mosaic, triticum mosaic, soil-borne mosaic and barley yellow dwarf could cost producers 5 to 10 percent or more in yield reductions per crop, but a major advance in developing broad disease-resistant wheat is on the horizon.
John Fellers, molecular biologist for the U.S. Department of Agriculture’s Agricultural Research Service, and Harold Trick, plant geneticist for Kansas State University, have led an effort to develop a patent-pending genetic engineering technology that builds resistance to certain viruses in the wheat plant itself. And although genetically engineered wheat is not an option in the market today, their research is building this resistance in non-genetically engineered wheat lines as well.
“(Wheat viruses) are a serious problem,” Trick said. “Wheat streak mosaic virus is one of the most devastating viruses we have. It’s prevalent this year. In addition to that, we have several other diseases, triticum mosaic virus and soil-borne mosaic virus, that are serious diseases.”
Knowing how costly these diseases can be for producers, Fellers has worked on finding solutions for resistance throughout his career. As a doctoral student at the University of Kentucky, he used a technology in his research called pathogen-derived resistance, or RNA-mediated resistance—a process that requires putting a piece of a virus into a plant to make it resistant to that particular virus. Most of the viruses that infect wheat are RNA viruses, he said.
“The plant has its own biological defense system,” Fellers said. “We were just triggering that with this technology.”
Now Fellers, with the help of Trick, his wheat transformation facility and K-State graduate students, have developed transgenic wheat lines that contain small pieces of wheat streak mosaic virus and triticum mosaic virus RNA.
“It’s kind of like forming a hairpin of RNA,” Fellers said. “What happens is the plant recognizes this RNA isn’t right, so it clips a piece of it and chops it up, but then it keeps a copy for itself. Then we have a resistance element.”
Fellers compared the process to the old days of viewing most wanted posters on the post office wall. The piece of foreign RNA from the virus, which is a parasite, is one of those most wanted posters. Because the virus is a parasite, it has to seize or hijack part of the plant system to make proteins that it needs to replicate.
When the virus comes into the plant, the plant holds up that poster from the post office wall, recognizes the virus, and doesn’t allow the virus to replicate and go through its lifecycle.
A broad resistance goal
Trick said it wasn’t difficult to incorporate the RNA into the wheat, as it involved a standard transformation process where the DNA encoding the RNA was introduced into plant cells, plants were regenerated from these transformed cells, and then the transgenic plants underwent testing for disease resistance.
“The problem with this technology is the most wanted poster is only for one individual,” Trick added. “If we were trying to target multiple genes, we’d have to make another vector for a second virus, then create that transgenic, which we have done. So, we have different plants that are genetically resistant to wheat streak mosaic virus and plants that are resistant to triticum mosaic virus. We would like to get something that has broad resistance to many different viruses.”
Knowing again that the viruses are parasites that rely on part of the plant system to replicate, it may be possible to shut off these plant systems to prevent viral replication, Trick said, which in essence means making a most wanted poster for specific plant genes.
Fellers and Trick have made additional transgenic plants with a most wanted poster for these plant genes and tested their new plants for resistance to a number of wheat viruses.
“We’re now able to target barley yellow dwarf and soil-borne mosaic viruses,” Fellers said. “We’ve also done mixed infection tests with wheat streak mosaic and triticum mosaic (viruses), and our initial results now are that they’re all resistant. We’re very cautious, but our initial indications show we have come up with something that provides broad resistance to these four viruses. We thought it was important enough to file for a patent.”
Fellers said this work is a proof of concept, meaning it shows that researchers have an ability now to address these virus issues. The fact that the process uses genetic engineering would mean that getting broad-resistance wheat would take some time considering the public and industry would have to accept it first.
However, Trick said they are now pursuing a non-genetically engineered method that involves turning off specific plant genes using mutations. With this method, the researchers could develop the technology and incorporate it into the K-State breeding program without regulations.
“We would hope the turn around time would be quick, but it’s still classical breeding,” Fellers said of using mutations. “It’s a matter of developing markers and getting them in the varieties. We have been using Jagger and Karl 92, varieties that are already past their prime, so we have to get them in some newer varieties.”
The Kansas Wheat Commission has provided funding for this research. More information about K-State’s Department of Plant Pathology is available online (http://www.plantpath.ksu.edu). A video interview with Fellers and Trick can be found on the K-State Research and Extension YouTube page (http://youtu.be/mXiw78MpS0E).

 

 

Read Full Post »

blq-blocks_grey_alpha

NEWS Science and Environment

7 October 2014 Last updated at 12:39 ET

By Claire Marshall
BBC environment correspondent

A closer look at how a tree injection works

Injecting trees with a concentrated form of garlic might help save trees in the UK from deadly diseases.

Operating under an experimental government licence, a prototype piece of technology to administer the solution is being trialled on a woodland estate in Northamptonshire.

Widespread use of the injection process is impractical and expensive.

But it could potentially help save trees of historic or sentimental value.

Garlic is one of nature’s most powerful antibacterial and antifungal agents.

It contains a compound called allicin, which scientists are interested in harnessing.

The experimental injection device is made up of a pressurised chamber and eight “octopus” tubes.

The pressure punches the solution through the tubes and through special injection units in to the tree’s sap system. The needles are positioned in a way to get allicin evenly around the tree.

The moment the active agent starts to encounter the disease, it destroys it. The poison is organic and isn’t rejected by the tree.

tree injection_78065849_78065848Tree injection

The treatment could potentially help save trees of historic or sentimental value
It is pulled up the trunk out along the branches and in to the leaves by the process of transpiration – the flow of water through a plant.

Tree consultant Jonathan Cocking is involved with the development and deployment of the treatment.

“Over the last four years we have treated 60 trees suffering badly with bleeding canker of horse chestnut. All of the trees were cured.

This result has been broadly backed up by 350 trees we have treated all over the country where we have had a 95% success rate.”

Oak trees with acute oak decline – which eventually kills the tree – have improved after being treated. In laboratory conditions allicin kills the pathogen chalara which is responsible for ash dieback.

The solution is made by a company in Wales. “Organic cloves of garlic are crushed,” said Mr Cocking, “and a patented method is used to amplify the volume of allicin and improve the quality of it so it is stable for up to one year. Allicin in the natural world only lasts for about 5-10 minutes.

If you go back to the tree the day after, and crush a leaf that is in the extremity of the crown, you can often smell the garlic.”

The goal is to get a commercial licence by the beginning of next year.

According to Prof Stephen Woodward, a tree expert at Aberdeen University: “The antibacterial properties of allicin are well-known in the laboratory. I have not heard of it being used in trees before, but yes this is interesting. It could work.”

However Mr Woodward cautioned about such methods of “biological control”. “Despite being plant-based that doesn’t mean it can’t harm an ecosystem. For example cyanide is plant-based.”

Many conservationists also caution against such drastic intervention. Dr Anne Edwards from the John Innes Centre was one of the first to identify ash dieback in a coppice wood in Norfolk.

She said that this treatment would not be effective for ash dieback: “In a woodland setting we really have to let nature take its course. It’s very depressing,” she explained.

The Woodland Trust also favours a different approach. The organization is investing £1.5m in a seed bank. The idea is to grow trees that are fully traceable and therefore free from foreign disease.

Austin Brady, director of conservation and external affairs, said: “Our native woodland needs to build its resilience to disease and pests. By starting from the beginning of the supply chain we can ensure that millions of trees will have the best possible chance of survival in the long term.”

In recognition of the threat posed by current and future tree and plant biosecurity, Defra recently appointed a Chief Plant Health Officer, and has earmarked £4 million for research in to treatments.

Read Full Post »

sci dev logo

 

http://www.scidev.net/global/farming/news/cheap-chemicals-entice-caterpillar-eating-wasps-to-crops.html

8B16D57EC04D470B1ECDE2E20E9DC85A image credit: Flickr/CIMMYT

Speed read
Plant growth promoters are already used to boost crop yields

Applying them early could also attract caterpillar-eating wasps

The researchers say seeds could be soaked in the chemicals before planting

[CAIRO] It may be a win-win situation: treating seeds with commercially available growth promoters before planting could have the added benefit of attracting parasitic wasps that feed on caterpillar pests, suggests a study.

The protective effect of these cheap, commercially available chemicals, known as ‘plant strengtheners’, can help protect young crops when they are particularly vulnerable to caterpillars, according to research published last month (19 February) in the Philosophical Transactions of the Royal Society B.

“In the new study we show that the effect is long-lasting: even a week after treatment, we can see the effect,” says study co-author Ted Turlings, an ecologist at the University of Neuchâtel, Switzerland.
——————————————————————————–
“This is an excellent pest control strategy.”

Mohamed Ragaei, Egyptian National Research Centre

———————————————————————————
It is estimated that pathogens and pests account for 25 to 40 per cent of total crop loss. When under attack, plants naturally emit oils that attract the natural predators of the pests. It is possible to up-regulate this process — so more oil is emitted— using genetic modification.

But genetic modification up-regulates only the production of specific chemicals, and research indicates that it is a mixture of various chemicals that is most effective at attracting predators.

Since the mid-2000s scientists have known that spraying with plant strengtheners — a generic term for compounds that boost the vigour, resilience and performance of crops — also elicits the release of a range of extra predator-attracting chemicals. Though the exact biology involved is not well understood and the technique had not performed well in field trials.

Turlings team thought that this poor performance during previous large trials might be partly because the strengtheners were applied too late and partly because heavily pest-infested fields were used for the trials. If this was the case, then the strengtheners could still be useful if applied earlier — by soaking seeds in them, for example.

The scientists tried this idea out on a small scale in their study; soaking maize seeds in two kinds of strengtheners for 12 hours, planting them, and — after a few days growth — counting how many wasps they attracted as compared with control seeds soaked in water. They found that plants treated with both kinds of strengthener, compounds known as BTH and laminarin, attracted more wasps than the controls. They say larger scale trials should now go ahead.

The researchers still do not know exactly how the growth promoters increase the attraction of the parasitic wasps. But they say that treating plants with them may be the most environmentally friendly and effective option available to simultaneously increase crop yields and attract pest predators. It is also cheaper and less controversial than genetic modification of seeds.

“I could imagine that cheap versions of the plant strengtheners could be used by subsistence farmers to boost the performance of their crops,” says Turlings.

Entomologist Mohamed Ragaei of the Egyptian National Research Centre in Cairo tells SciDev.Net that the approach looks “really promising”.

“This is an excellent pest control strategy,” he says. “Especially as the statistics show perfectly the effectiveness of a naturally treated plant to attract parasitoids and enhance the [oil] emissions.”

Link to abstract in Philosophical Transactions of the Royal Society B
References
Philosophical Transactions of the Royal Society B doi:10.1098/rstb.2012.0283 (2013)

Read Full Post »

Older Posts »

Follow

Get every new post delivered to your Inbox.

Join 218 other followers