...From the pages of Agricultural Research magazine
NAGP Makes Room for Swine Germplasm
The National Animal Germplasm Program (NAGP) has officially added swine
to its collection. Mandated by the U.S. Congress in 1990, the NAGP is
located at ARS' National Center
for Genetic Resources Preservation. Its first germplasm entry was 40
chicken lines cataloged in 2000. Consolidations in several meat-animal
industries have led to concerns about there being less genetic diversity
By collecting swine germplasm, NAGP will help provide breeders the
genetic tools needed to develop animals with important traits, such
as disease resistance. Work is under way on a national swine breed survey.
NAGP researchers are looking for ways to improve use of super-cold temperatures to preserve germplasm. Today's cryopreservation techniques result in very low conception rates and small litter size compared to industry norms. The scientists want to improve long-term germplasm storage and better understand how it affects sperm and embryo viability. They will also study proper storage of germplasm for beef and dairy cattle, small ruminants, and aquacultured species.
Exceptionally soft bicomponent yarn is being spun with a new tandem
spinning system. This patented system works 10 times faster than the
conventional ring-spinning one. It's a combination of two different
technologies: air-jet spinning and friction spinning. It greatly speeds
up the process by which two types of fibersor two strands of the
same type of fiber, of the same or different qualitycan be coaxially
blended into a continuous yarn strand. By wrapping one fiber around
another, a core-wrap yarn is formed that exhibits qualities inherent
in both fibers. Often, the core material is a strong synthetic fiber
that imparts such useful mechanical and functional properties to fabric
as durability, dimensional stability, and wrinkle resistance. An outer
wrap of cotton adds desirable comfort characteristics.
Fabric made with this tandem-spun yarn doesn't pill, since the core fiberoften a high-tenacity polyester that is prone to cause pillingis almost completely encased in cotton, which doesn't pill. After heat-setting, this "thermoplastic" core fiber usually provides satisfactory shrink- and wrinkle-resistance to fabric, while the outer layer of cotton provides the softness and absorbency of a natural fiber. The tandem spinning technology is now available for licensing by textile processors.
A few years ago, eucalyptus trees seemed to offer promise as salt-tolerant
plants that could draw up and use salty irrigation-drainage water. Although
the trees survived, they used little of the saline water, so they didn't
thrive and grow much.
Now attention's turned to finding salt-tolerant forages that would reduce the volume of salty drainage water while providing feed for grazing sheep and cattle. Researchers used an elaborate sand-tank system to test a variety of forage species. After ranking them by forage quality, production potential, and mineral ion accumulation, the scientists found that cultivars of alfalfa and tall wheatgrass performed best in the experiment. After completion of field tests and ruminant nutritional studies, it may be possible to recommend forages that will not only feed grazing animals, but also help solve the problem of saline irrigation water disposal.
Concerns about pesticide use have led breeders to develop broccoli
varieties with natural resistance to downy mildew. Growers formerly
dependent on fungicide applications to prevent this costly scourge can
now simply grow varieties resistant to the fungal cause, Peronospora
parasitica. But fungi and other plant disease agentsas well
as insect pestsare notorious for developing an ability to overcome
resistance in plants, over time. So it's very good news that scientists
have found genetic markers that easily identify broccoli varieties with
natural resistance to downy mildew. These markers will aid development
of future varieties with more durable resistance.
The long-range goal is to gang, or "pyramid," several resistance genes into new broccoli varieties, to build in multigene protection that will be much harder for disease-causing microbes to overcome. Another goal is to improve understanding of how plants inherit their resistance. By studying how it works with one or more particular varieties, scientists will be able to devise strategies for breeding resistance in new and better broccolisas well as in related cole crops, such as cauliflower and cabbage.
"Science Update" was published in the March 2003 issue of Agricultural Research magazine.