Read the magazine story to find out more.

ARS fish physiologist Rick Barrows and Montana Microbial Products have developed a barley protein concentrate that could replace fishmeal to make a less expensive feed for trout and other commercially produced fish.

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Barley Protein Concentrate Could Replace Fishmeal in Aquaculture Feeds

By Sharon Durham
February 5, 2010

Agricultural Research Service (ARS) scientists and Montana Microbial Products (MMP) of Butte, Mont., have developed a barley protein concentrate that could be fed to trout and other commercially produced fish.

Physiologist Rick Barrows at the ARS Small Grains and Potato Germplasm Research Unit in Aberdeen, Idaho, teamed with MMP to apply for a patent on a new enzymatic method that concentrates barley protein and produces raw material for another valuable commodity—ethanol. This process provides a high-protein ingredient that may replace other, more expensive protein sources like fishmeal and soy protein concentrate in commercial fish feed.

Currently there is no commercial production of barley protein concentrate, but MMP is producing small quantities for fish-feeding studies with trout, salmon and other species. MMP projects that the concentrate will sell for $700 to $1,200 per ton. Since fishmeal costs about $1,200 per ton, the projected costs of barley protein concentrate compare favorably.

Feeding trials conducted by the Aberdeen researchers and MMP show that barley protein concentrate successfully replaced both fishmeal and soy protein concentrates in fish feed, meeting the fishes’ protein requirements. Barrows and other researchers in the ARS unit also are examining the genetics of barley to modify the grain for improved protein yield and nutritional composition.

According to Barrows, feed is part of a complex interplay of genetics, nutrition and economics in fish production. Barley protein concentrate could completely replace fishmeal in fish feed if other essential nutrients are provided as supplements.

Using barley protein instead of fishmeal in commercial fish feed could help reduce the demand for millions of tons of fish taken from the ocean each year to produce fishmeal.

Read more about this research in the February 2010 issue of Agricultural Research magazine.

ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture (USDA). This research supports the USDA priorities of promoting international food security and developing new sources of bioenergy.

Read the magazine story to find out more.

ARS plant pathologist Martin Carson is using genes from a wild oat, considered by some to be a noxious weed, to help combat crown rust, the most damaging fungal disease of oats worldwide. ARS photo.

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ARS Scientists Turn to a Wild Oat to Combat Crown Rust

By Dennis O'Brien
February 4, 2010

Agricultural Research Service (ARS) scientists are tapping into the DNA of a wild oat, considered by some to be a noxious weed, to see if it can help combat crown rust, the most damaging fungal disease of oats worldwide.

Crown rust reduces oat yields up to 40 percent and shows a remarkable ability to adapt to varieties bred to genetically resist it. ARS researchers and colleagues have inserted individual resistance genes into oat varieties that produce proteins believed to recognize strains of crown rust and trigger a defense response against them. “Multiline” cultivars with several resistance genes also have been developed.

Crown rust is caused by Puccinia coronata, a fungus that reproduces both sexually and asexually and has enough genetic flexibility to overcome resistance genes, usually in about five years, according to Martin L. Carson, research leader at the ARS Cereal Disease Laboratory in St. Paul, Minn. His analysis also shows crown rust is increasing in virulence throughout North America.

Carson has turned to a wild variety, Avena barbata, for new genes with effective resistance. The slender oat, listed as a noxious weed in Missouri and classified as moderately invasive in California, grows wild in South Asia, much of Europe and around the Mediterranean region.

Carson inoculated A. barbata seedlings with crown rust. After several crosses, he found seedlings highly resistant to a variety of crown rust strains. In ongoing studies, he is crossing them with the domestic oat, A. sativa, to try to develop the right blend of resistance and desirable traits, such as high yield and drought tolerance. The goal is new plant lines that will effectively fight off crown rust for many years.

The research, which supports the U.S. Department of Agriculture (USDA) priority of promoting international food security, was published in the journal Plant Disease.

Read more about this research in the February 2010 issue of Agricultural Research magazine.

ARS is USDA’s principal intramural scientific research agency.

Read the magazine story to find out more.

ARS chemist Mark Schmitt is discovering what happens—biochemically—inside malting barley grains as they sprout, so that plant breeders will have a better basis for developing superior varieties.

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Secrets to Superb Malting Barleys Explored by ARS Researchers

By Marcia Wood
February 3, 2010

Many favorite breakfast cereals, candies, beers, and other foods and beverages owe much of their smooth, delicious flavor to malt. Malting barleys—the source of that malt—are the focus of studies at the Agricultural Research Service (ARS) malting barley laboratory in Madison, Wis., part of the agency's Cereal Crops Research Unit.

There, chemist Mark Schmitt and plant physiologist Allen Budde are discovering more about what goes on inside barley grains as they germinate, or sprout, in the malt house. Sprouting is one of many steps that go into making malt.

Findings from the scientists' basic and applied research help plant breeders develop even better malting barleys for tomorrow. Of particular interest to Schmitt are the specialized enzymes that the grain creates while it is sprouting. These enzymes, for example, convert the grain's stored proteins into their component amino acids, and convert the stored carbohydrates into what are known as "simple sugars."

Schmitt is also interested in the balance of this breaking down of proteins and carbs. That balance can affect the malt's flavor and other qualities.

Some of the team's current research into barley enzymes follows up on studies they reported several years ago. In one investigation, Schmitt found that enzymes called serine-class proteases, which break down proteins in the sprouting grain, can also break down beta-amylase, an important enzyme for converting carbs to simple sugars.

The study, a scientific first, was reported in a 2008 issue of the Journal of Cereal Science. The finding might help explain one of the patterns found in an earlier study, published in a 2007 issue of the journal Cereal Chemistry. In that analysis of more than 2,000 North American malting barleys, Schmitt and Budde found that high levels of a desirable, beta-amylase-associated attribute in the barleys correlated to low levels of the serine-class proteases.

Read more about this research in the February 2010 issue of Agricultural Research magazine.

ARS is the U.S. Department of Agriculture's principal intramural scientific research agency.

Read the magazine story to find out more.

ARS scientists have developed an efficient, cost-effective way to speed up the breeding of barley that is resistant to scab, one of the most devastating wheat and barley diseases worldwide. Click the image for more information about it.

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ARS Researchers Develop Method to Speed Up Breeding of Scab-Resistant Barley Cultivars

By Alfredo Flores
February 2, 2010

Agricultural Research Service (ARS) scientists have developed an efficient and cost-effective method to speed up the breeding of scab-resistant barley cultivars, thus improving crop quality for small-grain breeders in the Northern Plains.

Shiaoman Chao, a molecular geneticist at the ARS Cereal Crops Research Unit in Fargo, N.D., collaborated with scientists from North Dakota State University and the University of Minnesota in the study.

Chao used genomics information provided by the breeders to develop DNA markers tagged to important agronomic traits. Once appropriate markers were identified that tagged the useful genes, the markers were used in breeding populations to increase the efficiency of selection. The Fargo lab also developed procedures to speed up marker-assisted breeding.

Marker-assisted breeding is the process used to select plants carrying a trait of interest, such as resistance to scab (Fusarium head blight), which has cost U.S. farmers more than $3 billion since 1990.

This work would not be possible without the cooperation of the breeders, who collected barley samples for the Fargo lab to analyze.

Read more about this and other ARS barley and oats research in the February 2010 issue of Agricultural Research magazine.

ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture. This research is part of the U.S. Wheat and Barley Scab Initiative and supports the USDA priority of promoting international food security.

Read the magazine story to find out more.

ARS chemist Mitchell Wise is studying environmental factors that influence how oats produce avenanthramide, a potent antioxidant that is part of what gives oats a reputation for health benefits. Click the image for more information about it.

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Studies Provide Insight into Key Oat Chemical

By Stephanie Yao
February 1, 2010

Studies conducted by Agricultural Research Service (ARS) scientists are helping to increase understanding about the environmental factors that regulate avenanthramide (Avn) production in oat grain.

Avns, metabolites with potent antioxidant properties, are one reason oats have been widely touted for their many health benefits. The specific purpose of Avns inside the oat plant is still largely unknown, but previous studies have found an increased production of Avns in oat leaves when the plant is attacked by a fungus. This finding leads researchers to believe that Avns help oat plants fight off these fungi.

Chemist Mitchell Wise with the ARS Cereal Crops Research Unit in Madison, Wis., teamed up with fellow chemist Doug Doehlert with the ARS Red River Valley Agricultural Research Center in Fargo, N.D., to examine the correlation between disease pressure and Avn concentration in the oat grain.

The scientists tested 16 oat cultivars and two breeding lines at three locations in North Dakota over a two- year period. They found that oat plants with the strongest crown rust resistance typically had the highest Avn concentrations in environments where crown rust occurred. They also found that Avn production is likely influenced by additional environmental factors, because not all cultivars with strong crown rust resistance produced high Avn concentrations. Details of this study can be found in the scientific journal Cereal Chemistry.

Still, according to Wise, the results suggest that oat breeders—taking into account crown rust pressure during growth—can select certain cultivars for enhanced production of Avns.

Wise is also further researching the biosynthesis of Avns in the laboratory. He developed a suspension culture system from oat shoot tissue in which Avns are produced in response to a chemical that mimics fungal infection. This useful tool can be used for more detailed investigation into how certain Avns are produced.

Read more about this research in the February 2010 issue of Agricultural Research magazine.

ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture (USDA). This research supports the USDA priorities of improving nutrition and health and promoting international food security.

Micrograph of orange rust pushing out of a sugarcane leaf. Photo courtesy of Linley Dixon and David Farr, ARS.

ARS scientists have analyzed rust fungi from more than 160 sugarcane samples from 25 countries to help breeders and pathologists looking for genetic resistance to rusts, especially the deadly newcomer orange rust. Click the image for more information about it.

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ARS Genetic Analysis Helps Spot Sugarcane Rusts

By Alfredo Flores
January 29, 2010

Agricultural Research Service (ARS) scientists have analyzed rust fungi from more than 160 sugarcane samples from 25 countries to provide a valuable resource for plant breeders and pathologists who are searching for genetic resistance to the deadly orange and brown rusts.

These diseases are a major concern for the sugarcane industry, so correctly diagnosing which rust is present is key, according to Lisa Castlebury, a mycologist at the ARS Systematic Mycology and Microbiology Laboratory in Beltsville, Md. Accurately distinguishing rust isolates by appearance alone is difficult, since their form and structure are very similar.

The rust known as “orange rust,” different from the standard “brown rust” that is common in U.S. sugarcane production, was found in Florida in 2007. With orange rust, a minimum of three fungicide applications are needed to still achieve acceptable yields, and those applications cost growers an estimated $40 million annually in Florida, the only U.S. cane-producing state that has this rust so far.

The study started as a simple request to Castlebury from ARS research plant pathologist Jack Comstock in Canal Point, Fla. Castlebury led a scientific team to genetically analyze and compare DNA sequences from sugarcane rust fungi. In the study, now in its third year, samples have been also been analyzed with light microscopy to spot the subtle differences between the two rusts. Postdoctoral research associate Linley Dixon at the Beltsville lab also participated in the study.

Castlebury and APHIS mycologist John McKemy identified the new orange rust found in a sugarcane-growing area in Florida, the first find in the Western Hemisphere. Now the study has turned into a global analysis of rust fungi affecting sugarcane cultivars, in collaboration with Comstock and ARS research molecular biologist Neil Glynn in Canal Point. The majority of the sugarcane samples Castlebury receives come from the Americas, Asia, Australia, and, to a lesser extent, Africa.

The results of the scientific team’s genetic sequences have been added to GenBank, the National Institutes of Health’s genetic sequence database, for use by plant pathologists and plant breeders.

ARS is the chief intramural scientific research agency of the U.S. Department of Agriculture. This research supports the USDA priority of promoting international food security.

The raccoon roundworm specimens that ARS zoologist Eric Hoberg is examining are part of the U.S. National Parasite Collection in Beltsville, Md. Click the image for more information about it.

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ARS Parasite Collections Assist Research and Diagnoses

By Sharon Durham
January 28, 2010

Collections of organisms that cause harm, disease and damage are important in allowing Agricultural Research Service (ARS) scientists to explore the diversity, evolution, and distribution of parasites and pathogens.

ARS researchers have assembled and maintained invertebrate protist collections at three locations for the purpose of in-house and joint projects. Protists are organisms with simple cellular structures, and can live in any environment that contains water.

At the Center for Medical, Agricultural and Veterinary Entomology (CMAVE), in Gainesville, Fla., researchers are using a collection of microsporidia to act as soldiers of biological warfare at the tiniest level against red imported fire ants.

CMAVE entomologist David Oi is using species of spore-producing insect pathogens, such as Kneallhazia solenopsae, to bring about declines in red imported fire ant (Solenopsis invicta) populations. In Argentina, these infectious soldiers are associated with localized declines of 53 percent to 100 percent in fire ant populations, according to Oi.

In addition, Oi and CMAVE colleagues Sanford Porter and Steven Valles were able to get K. solenopsae to infect phorid flies without harming them. That’s important because phorid flies may serve as vectors to infect red imported fire ants with the microsporidia—perhaps facilitating the spread of infection to other colonies.

Invertebrate protist collections are also maintained at ARS facilities in Sidney, Mont., and Manhattan, Kan.

ARS also keeps archival collections of parasites, such as tapeworms, for research, identification and diagnostic purposes. The vast majority of these are in the U.S. National Parasite Collection, curated by zoologist Eric Hoberg in the ARS Animal Parasitic Diseases Laboratory in Beltsville, Md.

This collection was established in 1892 and is among the largest parasite collections in the world. It holds more than 20 million catalogued specimens representing nematodes, tapeworms, flukes and some parasitic arthropods, such as fleas, ticks and lice. Such archives provide a foundation to identify shifting geographic and host ranges for parasites and diseases that may emerge with accelerated global climate change.

Read more about this and other important collections in the January 2010 issue of Agricultural Research magazine.

ARS is the primary intramural scientific research agency of the U.S. Department of Agriculture.

Spraying a yeast called Pichia anomala onto almond, pistachios, or other nut trees is an environmentally friendly approach recently developed by ARS scientists for controlling aflatoxin-producing molds. Photo courtesy of the Almond Board of California.

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Helpful Yeast Battles Food-Contaminating Aflatoxin

By Marcia Wood
January 27, 2010

Pistachios, almonds and other popular tree nuts might someday be routinely sprayed with a yeast called Pichia anomala. Laboratory and field studies by Agricultural Research Service (ARS) plant physiologist Sui-Sheng (Sylvia) Hua have shown that the yeast competes successfully for nutrients—and space to grow—that might otherwise be used by an unwanted mold, Aspergillus flavus.

A. flavus and some other Aspergillus species can produce troublesome toxins known collectively as aflatoxins.

Hua has received a patent for use of the yeast as an eco-friendly way to protect tree nuts, as well as corn, from becoming contaminated with aflatoxins. Standards set by the U.S. Food and Drug Administration help prevent sale of aflatoxin-contaminated food and feed.

In tests conducted in a California pistachio orchard, Hua and colleagues found that spraying the trees with the yeast inhibited incidence of A. flavus in pistachios by up to 97 percent, compared to unsprayed trees.

The yeast can also be sprayed on the harvested or stored crop instead of on trees before the harvest, according to Hua, based at the ARS Western Regional Research Center in Albany, Calif.

Besides inhibiting the A. flavus fungus, the versatile yeast may also be effective in protecting other crops against any of at least half a dozen other species of microbes that can ruin a food's taste, texture, yield, safety or other attributes. Those microbes include, for example, Botrytis cinerea, which causes gray mold of table grapes.

ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture. Hua's research is one of many studies conducted at ARS labs nationwide to support the USDA priority of food safety.