NEWS 498 EDIT THIS Karoline KastanekLOCATED IN BFC

Brief #3 – Germplasm April 09, 2010Germplasm: agriculture’s insurance policy

Imagine if a dab of paint from each Leonardo da Vinci painting could be stored and used

to duplicate each of his paintings. Just a dab of paint touched to a blank canvas and, “voila” – an

exact replica of the Mona Lisa grows out from the dab of paint! That dab of paint is what

germplasm is for an entire plant species, except there is a bit more than just “voila.”

Germplasm is a piece of plant material suspended in growth. For example, scientists may

collect a plant’s seed, flower bud, cell or tissue and freeze or suspended its growth. Just as da

Vinci produced more than just one painting, a plant species has more than one variety, or genetic

variability. The U.S. Department of Agriculture’s National Germplasm Resources Laboratory

Web site said, “Well-documented plant genetic diversity in germplasm collections provides plant

breeders and other scientists with the raw materials necessary for crop improvement and other

research efforts.”

After harvesting germplasm, scientists keep it alive in a dormant stage until they need it.

Molecular Plant Biotechnology’s Web site said that scientists can use liquid nitrogen to lower the

plant material’s temperature and thus, suspend plant material growth. Scientists can also reduce

the oxygen concentration in the storage area or give germplasm hormones to slow its growth.

To improve crop traits, scientists all over the world store germplasm. “INTSORMIL

scientists have stored and used germplasm as seed since inception of the program,” said Dr.

Yohe, director of INTSORMIL. Yohe said that these scientists preserve germplasm in seed form

in dry, cold storage places such as the facility in Lubbock, Texas. This collection of sorghum,

millet and other small crop material has helped INTSORMIL scientists develop new crop

varieties that can survive adverse climate conditions such as drought, cold temperatures and soil

low in nutrients.

Don Lee, an agronomy professor at the University of Nebraska-Lincoln, explained that

the greatest genetic diversity of a plant can be found in its place of origin. Thus, INTSORMIL

scientists harvest most of their sorghum and pearl millet germplasm from Africa. As more uses

of sorghum and pearl millet develop, scientists are also constantly experimenting to find varieties

with higher yield potential for more uses than just grain.

For example, Ismail Dweikat, an INTSORMIL scientist at the University of Nebraska-

Lincoln, uses transgenetics to study sorghum cellulose. The transgenetic process occurs when

scientists select a gene from one plant species and insert it into the DNA strand of another plant

species. More foliage on a sweet sorghum plant increases its content of cellulose, a main

component used to produce biofuels.

Transgenetics may work well for increasing foliage in sorghum, but not necessarily for

seed. Some scientists are saving germplasm to combat what Lee calls “genetic escape.” Lee said

that when scientists genetically modify crops like sorghum harvested for seed (grain sorghum),

the herbicide-resistant genes may crossbred into weeds in the same family as the crop.

For example, if a U.S. farmer plants transgenetic grain sorghum unharmed by herbicide

in his or her field, the grain sorghum could crossbreed with its relative and noxious weed,

shattercane. After crossbreeding with the transgenetic grain sorghum, the shattercane seed also

becomes tolerant to the herbicide. This makes it harder for farmers to control shattercane in their

fields. In effect, scientists store germplasm to make better sorghum. It’s like insurance for

genetic diversity.

Just as Mona Lisa has her place in the Louvre, germplasm has its place in agriculture.