Science and Serendipity Defeat Invasion of the Air Potato

The plot could have come from Hollywood — an insidious alien invader threatens to overrun the land, but intrepid scientists discover a secret weapon in the far-off, exotic land of Nepal and bring the pestilence to heel. But this is not fiction; it’s true.

The air potato plant (Dioscorea bulbifera) is an exotic vine from Asia that was introduced to Florida about 115 years ago to make medicine. After escaping from the lab, it multiplied and smothered native plant communities in all of Florida’s 67 counties in vines that grew 6 inches per day.

All attempts to manage the air potato were unsuccessful, until scientists from the ARS Invasive Plant Research Laboratory in Fort Lauderdale, FL, made their historic trip to Nepal.

To learn more read this article.

How Can an App Beef Up Cattle Production?

Everyone would like to see a few extra dollars in their wallets, right? Ranchers are no exception, and researchers at ARS’ Meat Animal Research Center in Clay Center, NE, are developing a web-based tool that will help cattle producers do just that. Called iGENDEC, for internet genetic decisions, the internet app will give beef cattle producers a way to select the best bull for their herds. Early testing has shown promising results.

Read Want To Beef Up Cattle Production? There Will Soon Be an App for That to learn more.

Grape Expectations

When was the last time you had to pick seeds out of your teeth when you ate a grape? Most likely, never! That's because ARS has bred "seedless" grape varieties with seeds so tiny that you can't even detect them.

Popular varieties include Flame Seedless, Crimson Seedless, Thomcord, and Autumn King, to name just a few. Sunpreme is a variety perfect for drying raisins on the vine. ARS pioneered a technique called "embryo rescue" to create new seedless varieties from existing ones.

Watch this video New Sunpreme Grape Variety from USDA-ARS

Really-Good-For-You Health Bars

Micronutrients are vitamins and minerals we need in small amounts for best health. ARS researchers helped formulate a tasty fruit-based bar with specific micronutrients and other health-promoting ingredients. Study participants who ate two bars a day for 8 weeks had improvements in several health indicators without making any other dietary changes.

To learn more read "Micronutrient-Packed Bar Improving Metabolic Health Goes Commercial."

ARS in Your Pizza

Great pizza needs great ingredients! Did you know that two of those were developed by ARS?

The oblong-shaped Roma (or "plum") tomato was developed in 1955 in Beltsville, MD, by ARS scientist William Porte. It was bred from the San Marzano and Red Top varieties to resist wilt and pests and grow well in different climates. But it also has a heavy, fleshy outer wall that makes it perfect for making sauces for pizza and spaghetti. And it contains lycopene, a nutrient with anticancer properties.

Mozzarella cheese is gooey and tasty topping for pizza, but it adds fat. ARS scientists in Wyndmoor, PA, invented a technology for making lower-fat mozzarella cheese that retains its stretchy, meltable texture and delicious flavor. They did this by modifying the network of the milk protein casein. The cheese has been widely used in school lunch programs since 1995.

Read Celebrating 15 Years of a Healthy School Lunch Option.

Can Baby Food Affect Your Health As An Adult?

Do you ever wonder what the future holds? No, we’re not talking about staring into crystal balls or reading tea leaves. A scientist in Houston, TX, has stumbled onto the answer of how what you eat at certain stages of life may determine your future health, and it’s call epigenetics.

Robert Waterland, professor of pediatrics-nutrition at the ARS Children’s Nutrition Research Center at Baylor College of Medicine, found a naturally occurring process in which DNA molecules are modified in ways that affect gene expression – including genes that regulate the body’s ability to use sugar. This premature epigenetic process may help explain how overnutrition during infancy increases the risk of diabetes later in life.

Waterland said we still have a lot to learn about these complex processes, but one promising insight is that this might present opportunities for pharmacological interventions to slow or even reverse epigenetic aging, if we can understand it.

Want to learn more? Read "Infant Overnutrition May Lead to Health Problems Later in Life".

Appendix A: Resource Material

Saline and Alkali Soils

Saline and alkali soils have excessive levels of soluble salts, consisting mainly of sodium, calcium, magnesium, chloride, and sulfate and secondarily of potassium, bicarbonate, carbonate, nitrate, and boron. Soluble salts in the soil water (soil solution) can be high enough to negatively affect plant growth.

Saline and alkali soils are common in arid and semi-arid parts of the world. Low precipitation and low soil permeability in arid ecosystems contribute to the buildup of salts in the soil that would be leached by water down to deeper soil layers below the plant root zone.

Excess levels of salts in the soil root zone limit the ability of plant roots to absorb soil water. Water flows osmotically from low salt concentration to higher salt concentration. Roots uptake water osmotically by having a higher salt concentration than the surrounding soil water pool. Saline and alkali soils reverse the osmotic potential of plant roots and soil water.

One agricultural solution to improve salt effected soils is to “leach” the salts down deep into the soil using a lot of water. By leaching the salts below the root zone, plants can grow normally; but not all salts are equally mobile in water. Table salt is more soluble in water than baking soda because of the difference in polarity, bond types, and compound size.

The Plant Growth and Osmotic Potential project was brought to you by the Great Basin Rangelands Research Unit in Reno, NV. 

Plant Growth and Osmotic Potential

Water is a critical element for plant growth. All water used by land plants is absorbed from the soil by roots through osmosis. Osmosis is the movement of a solvent (e.g.water) across a semipermeable membrane from low solute (e.g.salt) concentration towards higher solute concentration. Excess levels of salts in soils makes soil water solute concentrations higher than in the plant root cells. This can limit plant water uptake, making it harder for plants to grow. (See Appendix A for more information)

About the Experiment

For this experiment, we’re going to test the effect that high salt soil concentrations have on plant growth and root development.

	Details Ages - 12+
	Time - 1 hour set up - a few minutes a day for 3+ weeks
	Difficulty - Easy/moderate

 What You'll Need

• 7 clear plastic cups (Solo cups)
• 7 non-clear plastic cups
• Potting soil (small bag)
• Wheatgrass or cat grass seed (250 seeds, can be found online or at local pet store)
• Salt
• Baking soda
• Measuring spoons
• Drill & small bit

When using table salt (sodium chloride) and baking soda (sodium bicarbonate) to create saline and alkali soils, you can observe the germination and growth of grass leaves at increasing levels of salt and ph. Then you can treat the salt/alkali effected soils with "leaching" and observe plant growth.

Let's Do This!

1. Drill 3 small holes in 7 clear plastic cups. Have an adult help with this step for safety.

2. Fill 1 clear cup (with holes) with soil 1” from top of cup and place cup inside non-clear cup (without holes).

Pour ½ cup of water into the soil cup and allow to absorb. Pour another ½ cup of water into the soil cup.

Place 30 grass seeds on top of the wetted soil and cover with 1/8” of new soil and gently wet. Make sure seeds are covered with soil (Label cup “Control”).

3. Fill 3 clear cups (with holes) with soil 1” from top. Add 1 teaspoon of salt to the soil of 1 cup (label cup “salt 1”). Add 1 tablespoon of salt to the 2nd cup (label cup “salt 2”). Add 3 tablespoons of salt to the 3rd cup (label cup “salt 3”).

Place each cup in a non-clear cup (no holes) and add ½ cup of water to each and let absorb. Add another ½ cup of water.

Place 30 grass seeds in each cup and cover with 1/8” of new soil and moisten new soil. Make sure seeds are covered with soil (Image 2).

4. Fill 3 clear cups (with holes) ¼ full with soil. Add 1 tablespoon of baking soda to 1st cup and add more soil to fill cup 1” from the top. Hold your hand over the cup so soil does not spill and shake the cup to mix the baking soda with the soil (label cup “alkali 1”).

Add 2 tablespoons of baking soda to the 2nd cup and fill with soil 1" from top. Again, with hand over cup, shake to mix baking soda and soil (label cup “alkali 2”).

Add ½ cup of baking soda to the 3rd cup, fill with soil 1" from top and shake to mix (label cup “alkali 3”).

Place each cup in a non-clear cup (no holes). Add ½ cup of water to each and let absorb, then add another ½ cup of water. Place 30 grass seeds in each cup and cover with 1/8" of new soil and moisten new soil. Make sure seeds are covered with soil.

5. Let grass germinate and grow for 1 week.

Let’s Look At The Results!

After 1 week count the number of plants in each cup and measure the tallest blades of grass in each cup. Record the numbers for each on the data sheet. Remove the clear cups and observe root growth.

After 1 week, remove “salt 2” and “alkali 2” clear cups from red cups and place in the sink or outside (where water can drain) and slowly pour 6 cups of water through each, making sure to not over-fill (pour ½ cup at a time and let drain).

Observe which cups drains fastest (alkali soils have poor drainage). Make sure seeds are still covered with soil (add some on top if necessary) and let them grow for 1 more week.

After 1 week (2 weeks total) observe if “leached” cups now have plants that are growing. Did leaching help the same for saline vs. alkali soils?

After 2 weeks, measure the height of plants in each cup and record the results. Again, observe the roots and record observations on the data sheet.

Summarize your data and observations.

1. Why did plants grow or not grow in each cup?
2. What effect did leaching have on plant growth and why?
3. Did leaching work on both salt and baking soda equally and why?

Eat Fish! Which Fish? That Fish! Go Fish!

For a healthy heart, the American Heart Association and the Dietary Guidelines for Americans recommends eating two, 3.5 oz servings of fish per week. Questions like “Why? Which fish?” immediately come to mind.  Also, “Is wild-caught fish better than farmed?”

Several studies have shown that eating fish reduces risk of heart disease. Fish is an excellent source of protein and many species are also rich in omega-3 fatty acids, particularly the long chain omega-3's EPA and DHA.

USDA scientists at the Grand Forks Human Nutrition Research Center are studying ways to lower the cost of farming fish while improving omega 3 content and fillet quality. To find out the nutrients in different fish or create a personal eating plan, the USDA provides a free interactive tool called SuperTracker.

Read this article to learn more.