Focus
on Research
Penn State Intercom......September
6, 2001
What's blue and white and red
all over?
Get a gander at the
Penn State Cherry Tomato
By Jeffrey J. Mulhollem
College of Agricultural
Sciences
A College of Agricultural Sciences researcher has developed a soon-to-be released tomato hybrid that may save growers millions of dollars and provide incalculable benefits to public health.
The new tomato, tentatively called the Penn State Cherry Tomato, grows on plants that are resistant to diseases that typically ruin nearly a third of Pennsylvania's tomato crop. Also, the fruit contains three times as much of the powerful antioxidant compound lycopene as do other cultivated strains of tomatoes. Research has shown that lycopene in the diet helps prevent many types of cancer and heart disease.
Majid Foolad, associate professor of plant genetics and breeding, has spent seven years developing tomatoes for Pennsylvania.
Unlike other strains of tomatoes developed primarily for California and Florida, where more than 90 percent of the country's tomatoes are grown, the Penn State variety thrives in Pennsylvania's climate.
Foolad also is conducting research to improve tomato cold tolerance and adaptation to Pennsylvania conditions.
The new variety can
resist fungal blights common in the Keystone State. 
That's big news because
tomatoes are Pennsylvania's second biggest vegetable crop, after sweet
corn, with an annual harvest worth more than $16 million.
Foolad says early and late blight wipe out an average 30 percent of tomatoes grown in Pennsylvania. Most commercial growers spray costly fungicides 10 to 15 times during the growing season to protect their crops, at an estimated
$1 million cost statewide annually.
Ironically, Foolad found the ingredients for the improved strain deep in the tomato's past. He started with wild seeds from the gene banks maintained at C. M. Rick Tomato Genetics Resource Center at the University of California, Davis, and the U.S. Department of Agriculture Plant Genetic Resources Unit, Geneva, N.Y. The tomato evolved millions of years ago in what is now Peru and Chile in South America. It was domesticated in Central America.
The resistance to blight and increased lycopene content were both found in wild tomato genotypes, which were painstakingly crossed and recrossed with cultivated tomato strains by Foolad and his associates to obtain desired qualities.
"We screened more than 300 genotypes in the first few years," Foolad added. "We evaluated for blight resistance, high lycopene content and other growth characteristics suitable for production in Pennsylvania."
The Penn State hybrid produces a deep red fruit compared to the paler color of other cultivated tomatoes. It is almost perfectly round, with an average diameter of slightly more than an inch.
The tomato will be "showcased" to growers, patented and released in the next year, Foolad said.
Jeffrey J. Mulhollem can be at jjm29@psu.edu.
Switching action may be
key to molecular computers
Your future computer may have components that function based on the action of single molecules. A step in that direction has been made by showing that single molecules can switch between "on" and "off" states, and then hold in a state for hours at a time.
According to researchers at Penn State and Rice University, specially designed single molecules can switch in that manner. In addition, conformational changes -- which happen when molecules alter their arrangement by rotation of their atoms around a single bond, effectively changing shape by moving or turning -- determine how and when that conductance switching occurs in those molecules.
Researchers determined that limiting conformational changes reduces switching between the "on" and "off" states. Just as squeezing a lot of people into a small room limits their ability to move freely, researchers determined the same thing was happening at a much smaller scale with molecules. Conformational changes do not occur as frequently when the molecules have less room to move in their host environment, or matrix.
Because switching provides the basis of logic and memory in computer systems, the discovery of what causes such switching in single molecules may help researchers move closer to making molecular computers a reality.
"We essentially tightened the noose around the molecule and showed that once its motion was reduced switching went way down," said Paul Weiss, associate professor of chemistry. "We have not worked out how to make computer architecture or anything close to that, but tackling the very small end, which is our specialty, has been an interesting and exciting project. Our next step is figuring out how to control the molecules' movement between 'on' and 'off.' "
For the full story, go to http://www.science.psu.edu/alert/Weiss6-2001.htm
Marketing professor produces
computerized mental maps
When it comes to marketing a product or service, marketers attempt to establish a unique place or position for it amongst the competitors. Recently, psychometricians have developed computer programs for producing maps of such mental perceptions among consumers using sophisticated mathematical models.
"Unfortunately, all such models for visually portraying a product or service's position to managers are grossly deficient for simultaneously depicting all the relevant aspects of positioning," said Wayne S. DeSarbo, the Smeal distinguished research professor of marketing in The Smeal College of Business Administration.
DeSarbo has developed a new mathematical procedure that can recreate on a computer how consumers perceive different products in their mind.
"It simultaneously depicts the competitive marketplace, brand rank and consumer attitude in a map, as well as deriving the market segments that underlie them," explained DeSarbo. Jianan Wu, assistant professor of marketing at Tulane University in New Orleans, co-authored his research article.