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A perennial legume may have the toughness to thrive in pastures in the
harsh Appalachian hills. ARS scientists have been growing tuberous
vetchling in nursery plots in West Virginia and Pennsylvania for two
years. They now have enough seed to begin field plantings for forage
evaluation this spring. A previously uninvestigated relative in the pea
family, tuberous vetchling has several advantages as a forage crop: It
grows in poor droughty soil, spreads by rhizomes and provides a home for
microorganisms that enable it to use nitrogen from the atmosphere. These
qualities, combined with its large seed size, make it ideally suited for
steep slopes that are more prone to erosion and difficult to seed or
fertilize with equipment. The plant's regrowth from rhizomes enables the
plant to persist in the nursery plots despite damage from deer which graze
the herbage and dig up and eat the fleshy tubers.
Appalachian Soil and Water
Conservation Research Laboratory, Beckley, WV
Joyce Foster, (304) 256-2809
New pea varieties that resist root rot could be closer to the market.
That's because ARS scientists have found how to rapidly identify
experimental breeding lines. Common root rot is the most destructive root
disease of peas worldwide. The fungus Aphanomyces euteiches causes
it, and no chemical control is available. The new test uses a chemical
compound to identify pea plants least hospitable to fungi. The test works
by measuring the chemical's reaction to compounds made by the fungus. Low
reaction indicates only a small amount of fungus--meaning the plant is
resistant. Until now, scientists searching for resistance faced a
time-consuming task--by either peering through a microscope to count
individual spores infecting root tissue, measuring root disease severity
or taking seed yield measurements.
Vegetable
and Forage Crops Production Research, Prosser, WA
John M. Kraft, (509) 786-9257
Creating soybean varieties that produce certain antioxidants could
eliminate the estimated five- to 20-percent losses caused by ozone
pollution. ARS scientists tested 20 soybean lines or varieties that
have varying amounts and kinds of naturally occurring antioxidants, called
flavonol glycosides. They found that only those plants with one or more
kinds of certain glycosides could tolerate high ozone levels. One of
these plants, a commercial variety called "Lee," was tolerant not only to
ozone, but also to excess soil manganese. That suggests the antioxidant
could protect soybeans against multiple stresses, such as manganese, ozone
and even ultraviolet rays. Scientists are searching for the genes
controlling production of antioxidants to use in creating ozone-tolerant
varieties. They also want to create improved synthetic versions of the
antioxidants to spray on crops.
Climate Stress Lab,
Beltsville, MD
Charles D. Foy, (301) 504-5522
Sweltering summer days may no longer hamper the health, longevity and
survival of certain maple trees growing in city landscapes. Many red
maples (Acer rubrum L.) and Freeman maples (A. x freemanii E.
Murray) are popular landscape trees that sometimes cannot tolerate
parched soil under concrete sidewalks. ARS and Iowa State University
scientists conducted two laboratory experiments to screen six red maples,
six Freeman maple cultivars and three unnamed red maples for their
tolerance to high root-zone temperatures. They measured above and below
ground growth and leaf chlorophyll content of trees at three soil
temperatures--75, 84 and 93 degrees F. Of the 15 maples tested, "Autumn
Flame," "Jeffersred" and "Schlesinger" appeared more resistant to high
temperatures; whereas "Franksred" and "Indian Summer" were more sensitive.
Next, the scientists plan to check out these results in field tests.
U.S. National
Arboretum, Washington, DC
Alden Townsend, (202) 245-4535
An unusual trait in plants--underground stems--was discovered in two new
native populations of fourwing saltbush, a nutritious forage for livestock
and wildlife. The shrubs found on New Mexico rangeland could be
forerunners of improved varieties for wider use on range habitats in the
West. Normally, fourwing saltbush spreads only by seed, but the new
strains also spread by underground stems. The trait appears to be
genetic, an indication it could be used to breed varieties that would
provide more forage for grazing livestock and wildlife, better control
erosion on disturbed lands and offer a new landscape option on private and
public lands.
Jornada Experiment Range, Las
Cruces, NM
Jerry R. Barrow, (505) 646-7015
Last updated: November 15, 1996
Return to: Quarterly Report
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