Crop Tech Corner

ST. LOUIS (DTN) -- This bi-monthly column condenses the latest news in the field of crop technology, research and products.

DON'T GAMBLE WITH APHIDS

The soybean aphid will always win the numbers game. Each year, aphid populations can produce multiple generations within a growing season in the same field, which makes them especially good at evolving resistance to insecticides. Now scientists have discovered that a large variety of aphid biotypes can exist in any given year, and those types can vary widely from year to year -- which gives the pest a leg up in overcoming resistant soybean varieties as well.

The discovery comes from a new study produced by scientists from a dozen universities, seed companies, and government institutions. The researchers used nine soybean lines with various Rag genes, a type of gene that gives soybean plants aphid resistance. Between 2004 and 2006, the aphid rapidly developed resistance to an aphid-resistant soybean line with the Rag1 gene, and this study set out to find out why.

For three years, the researchers plucked naturally occurring soybean aphid populations from nine Midwestern states and one Canadian province and tested them on the nine different aphid-resistant soybean lines. "The occurrence of soybean aphid biotypes was highly variable from year to year and across environments," the scientists concluded, which means the pest has far more genetic diversity than previously known. Several factors likely contribute to this variability, including the aphids' migratory patterns, their internal genetic diversity, their ability to reproduce asexually, and the abundance of buckthorn, which they overwinter on. Controlling the aphid with naturally resistant soybean lines will clearly never be simple, but the scientists did note that one variety with a pyramid of Rag1c and Rag4 genes had the lowest frequency of aphid colonization.

For more information, see the scientists' study here: bit.ly/1IUyUnI.

SORGHUM RESEARCH GETS A BOOST

The United Sorghum Checkoff Program has invested more than $6 million in 37 research proposals tackling crop improvement, the cultivation of high-value markets, and biofuel production. According to a Checkoff press release, the funds were provided by the program's board of directors, who have received 114 proposals for the funds since July.

The research projects of particular importance to grain sorghum farmers include:

-- $150,000 to Colorado State University weed scientist Todd Gaines to use mutagenesis to develop herbicide-resistance traits to help control grass weeds

-- $30,000 to Kansas State University weed scientist Mithila Jugulam to hunt for herbicide tolerance within sorghum germplasm

-- $160,000 to Kansas State University weed scientist Anita Dille to study the ecology of grass weeds that infest grain sorghum

For more information, see the press release here: http://bit.ly/…

CUKES HELP BREAK DOWN CORN FOR BIOFUEL

Scientists have swiped a gene from the cucumber plant to improve corn plants designed for biofuel production. A group of nine scientists, led by University of California-Davis plant scientist Sangwoong Yoon, zoomed in on cucumber's Cs-EXPA1 gene, which controls expansin protein. The protein helps loosen and break down plant cell walls, an important step in biofuel production. The researchers inserted and overexpressed Cs-EXPA1 in corn plants, and then selected the lines that produced the most expansin protein and performed best in tests. The transgenic corn lines did not exhibit any negative effects on growth or development and are now available for breeding improved biofuel corn varieties, the scientists said in the study abstract.

See the study abstract here: http://bit.ly/….

Emily Unglesbee can be reached at emily.unglesbee@dtn.com

Follow Emily Unglesbee on Twitter @Emily_Unglesbee

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