Hydraulic engineer Doug Shields (right) and student research assistant Rick
Rauteux observe changes in channel geometry and stream corridor habitats caused
by water rushing over a headcut.
Sticks and Stones May Brake Erosion
In silty southern streams, sticks and stones --willow posts and limestone
rocks --can protect bluegill, bass, and catfish from the effects of erosion
caused by watershed development. More roads, roofs, and fields mean more
rainwater reaching streams more quickly with greater erosive punch. That's why
Agricultural Research Service, the U.S.
Army Corps of Engineers, and USDA's Natural Resources Conservation Service in
1994 developed a cooperative project to restore stream and creek habitats. As
part of the effort, ARS conducted a 3-year study to determine which of the two
stabilizing techniques would be more effective in restoring fish habitat in a
stream damaged by extreme erosion. The limestone seemed slightly better, based
on diversity and number of fish, but the willows are more economical. The 7- to
20-foot dormant willow posts, planted in the streambanks, come to life in
spring and grow sturdy roots to protect the bank from erosion. Piles of
limestone rock --formed into ridges perpendicular to the current or parallel
with the bank --deflect currents and hold slumping banks in place.
F. Douglas Shields, Jr.,
Sedimentation Laboratory, Oxford, Mississippi; phone (601) 232-2919.
Two Proteins Determine Wheat Texture
ARS scientists have identified the elusive molecular basis for wheat
texture, referred to as hardness or softness. Generally, hard wheats are for
breads; soft wheats, for cookies and cakes. The discovery should help breeders
develop super-soft and other custom wheats. ARS researchers have shown for the
first time that two proteins called puroindolines --pinA and pinB --correlate
perfectly with wheat texture. All soft wheats have pinA and a specific form of
pinB that has glycine as its 46th amino acid. Most hard wheats differ from soft
wheat only in having serine as the 46th amino acid in pinB. The other hard
wheats tested have the glycine pinB and no pinA at all. With traditional
breeding or biotechnology, scientists could develop varieties with specific
puroindoline combinations. By boosting levels of soft-wheat puroindolines, for
example, they might create a super-soft variety for making new kinds of cakes
and cookies. That's because millers could grind the grain more finely than is
now possible without damaging the starch, a common milling problem.
Craig Morris, USDA-ARS
Western Wheat Quality
Laboratory, Pullman, Washington; phone (509) 335-4055.
Spud Book Holds 4,000 Pedigrees
A new compilation of more than 4,000 pedigrees of North American and
European potato varieties is available for the first time to potato breeders
and industry. An ARS geneticist compiled the handbook in collaboration with
scientists based in Poland, the Netherlands, and Ireland. The handbook gives
information on a variety's origin, year of release, countries of cultivation,
female and male parents, source or list of references, and unreleased ancestors
of currently cultivated varieties. Scientists compiled the information from
breeders and institutions preparing parental lines for breeding in the United
States, Europe, and Russia. In North America, the pedigrees are computerized
and also published in the American Potato Journal. European varieties, however,
are often released without publishing pedigree information. The handbook will
be available in both English and Polish. The United States ranks fourth
globally in potatoes, producing nearly 48 billion pounds a year.
Kathleen G. Haynes, USDA-ARS
Beltsville, Maryland; phone (301) 504-7405.
New Homegrown Hop Adds German Zest to Beer
Brewers and beer drinkers can now find the prized aromas of hops from
Germany's Tettnang region in ARS' new variety, Santiam. Hops give beer its
distinctive aroma and a zesty bitterness to balance the sweetness of malted
barley. While the original Tettnanger variety can be grown in this country, its
yields are lower than in Germany. Santiam, however, yields twice as much as
Tettnanger grown in Oregon, Washington, and Idaho, the principal hop-growing
states. Hop seeds can add undesired oils to beer, but Santiam is the first
naturally seedless Tettnang-type hop. With Santiam, ARS has now provided
domestic alternatives to all three premier European aroma hops: Tettnanger,
Hallertau, and Saaz. In 1997, ARS hop varieties accounted for two-thirds of the
U.S. harvest valued at $117 million. At least one-third of the hops in American
beers have ARS origins.
John Henning, USDA-ARS Forage
Seed Production Research Center, Corvallis, Oregon; phone (541) 750-8746.
"Science Update" was published in the August 1998 issue of
Agricultural Research magazine. Click here to see this
issue's table of contents.