GMO Shortens Life Span by Michael. This shirt design was submitted to Atrium in the No GMO t-shirt design challenge.

Threadless recently hosted* a t-shirt contest for Jeffery Smith‘s Institute for Responsible Technology: the No GMO t-shirt design challenge (see Karl’s post Vote for talking, not fighting for more details). One of the shirts really struck me: GMO Shortens Life Span by Michael. The artist proposes an equation:

plants + DNA  = death

This slogan really makes me wonder – does the artist know that plants have DNA? Does he know that his own cells are teeming with DNA? That without DNA, life wouldn’t exist? Do most people know that DNA is essential for life? What would the average person say if told that they eat about 100 thousand miles of DNA in the average meal?

If this is the level of understanding, or rather, misunderstanding, that persons have, can we ever expect to have useful discourse on the subject of biotechnology or even biology itself? This worries me greatly. Just in case anyone out there reading this is concerned that DNA is dangerous, I’d like to provide a simple recipe that anyone can use to see and touch DNA for themselves.

As shown in the picture below, DNA is tightly packed in each cell. It’s wrapped around proteins called histones, then coiled into the familiar X chromosome shape. The amount of DNA per cell depends on the species, but each cell has about 9 feet of DNA in it. Since each meal contains tens of millions of cells, you eat about 7 to 10 miles of DNA at each meal!

Cells to DNA. Image from Michigan State University.

There are a lot of DNA extraction recipes out there, but there are a few essential steps. The DNA must be freed from the cell membrane and the membrane of the nucleus. Then, the DNA needs to be separated from the membrane bits, proteins, and other cellular parts. Finally, the DNA needs to be precipitated, or brought out of solution by becoming a solid instead of being dissolved in the solution.

Supplies:

• Source of DNA. Fruit, especially banana or strawberries, works great because they have a lot of DNA per cell. Onions have a lot of DNA per cell too, but make for a much less pleasant smelling DNA extraction than berries or bananas.
• Detergent, such as shampoo or dish soap. Clear detergent is better so dye doesn’t cover up the action.
• Coffee filter to remove proteins, cell membrane parts, and other cellular gunk from your DNA solution.
• Table salt to precipitate proteins and carbohydrates.
• Ethanol to precipitate the DNA. Rubbing alcohol is ethanol, preferably 95%.
• A plastic sandwich baggie.
• 3 cups.
• A plastic teaspoon.
• A test tube or narrow glass like a shot glass.
• Toothpick.

Safety note: if you are tempted to taste the DNA, just remember that there is shampoo and rubbing alcohol in there and that these things are generally not good to eat! DNA itself, though, is perfectly safe – we eat it in every meal.  Really want to eat DNA? Check out these instructions for building an edible model.

*Just in case you were wondering, the contests aren’t vetted by Threadless, they are run by a separate site, Atrium. This was important for me, because I rather like Threadless, but I prefer to avoid patronizing companies whose publicized ethical stance I disagree with.

Caduceus with DNA via Ancestry.com

Francis Thicke, agronomist and organic dairy farmer in Iowa, asks:

Do you think there are unanswered questions about the health effects of GE foods? I have heard GE critiques frequently contend that there have been very few feeding trials on the health effects of GE foods, and that in the feeding trials that have been done, the results have raised questions about the safety of GE foods.

For starters, what is your opinion on the case of Arpad Pusztai and the results of his GE potato feeding trials that abruptly got him fired. Has anyone ever replicated his experiment?

There are a lot of important things to discuss in relation to these questions. Since it is so important, I have a few guidelines to suggest. To make this discussion easy to follow, please be careful to use the “Reply” button next to each comment if you want to stay in the same line of conversation (there should be up to 10 levels of replies allowed), or scroll to the bottom to the comment box if you want to start a new line of conversation. If you are making a specific claim, please provide a source, preferably a reliable one such as a scientific journal, government or university website, etc. Lastly, please try to stay away from fallacies such as the ones listed here. If we stick with sound information, we’ll all learn a lot more from the discussion.

The  study that Dr. Thicke refers to is Effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine (pdf) by Stanley W B Ewen and Arpad Pusztai. It appeared in the Lancet on 16 October 1999 after some controversy, alongside two commentaries: Genetically modified foods: “absurd” concern or welcome dialogue? (pdf) and Adequacy of methods for testing the safety of genetically modified foods (pdf).

Ewen SW, & Pusztai A (1999). Effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine. Lancet, 354 (9187), 1353-4 PMID: 10533866

Many World Food Prize Laureates have been scientists, and scientists are undoubtedly important in developing new crop varieties and new methods that can produce more food with fewer inputs, particularly for small famers. This year’s Laureates have a new message to share. As David Beckmann pointed out during his talk, great scientists are important, but it also takes groups like Bread for the World and Heifer International to organize and mobilize people to help. This year’s Laureates share a message of hope and inspiration.

David Beckmann

David Beckmann is the President of Bread for the World and President of The Alliance to End Hunger. He starts his talk with a positive note: there have been stunning changes for the better, including large reductions in child mortality due to hunger. Countries with reduced poverty include diverse countries like Brazil, Bangladesh, and Great Britain. Their successes show that it is possible to reduce hunger and poverty in our own communities and all over the world.

Bread for the World organizes people to change the politics of hunger. To make dramatic changes we need to change laws and systems. Front line work such as with food banks is important, but only make up about 6% of the food provided by US government programs like food stamps and school lunches. “We can not food bank our way to the end of hunger.”

Beckmann’s organizations help people make the connection between Jesus and justice, bringing Christian churches from many denominations as well as students, companies, and legislators together to work towards ending hunger. Bipartisan efforts have helped to triple US international aid in the last ten years. Even more important, that aid has been made more effective with a sharp focus on hunger issues. For example, the Obama administration was responsive to calls for improvement in international aid, but they did not have the political capital at the beginning of the term. Bread for the World helped provide political capital with millions of supporters. The results have been great, including a doubling of nutrition assistance to the hungry in the United States. As US elections approach, Beckmann urges us to consider which candidates will make time to help the hungry.

Beckmann, a Lutheran minister, concludes his talk with a reminder that God is calling us to help the hungry. He adds, if you don’t believe in God, the fact that hundreds of millions of people have escaped hunger should still be sacred. The proven effects of individual efforts should motivate us to work to help more people. “It’s not just about technology. We have to organize the give-a-damn to get it done.”

Sheri Reilly, campus minister at of St. Thomas Aquinas, who helps run a small farm in Ames, asked about problems with food aid, specifically referring to the problem of food aid to Haiti putting local farmers out of business. Beckmann replies: “food aid needs to be fixed”. The US needs to provide cash to buy food from farmers, not grain, whenever possible. For example, the biggest need is food for babies, but babies don’t eat grain. We need to look beyond grain as aid. The US spends two billion dollars a year on food aid. If we took half of that and used it to purchase food in country, we would get double the aid value. Originally food aid was about using up US surplus but now the amount of US food used for crops is minuscule. The problem is that there are a handful of shipping companies that are making money from shipping food aid grain – tax dollars are being used to pay these companies. There is also resistance to change from congressmen that is difficult to cut through.

In response to a question about subsides, Beckmann says that there is a higher rate of poverty in rural America but the poverty affects small farmers disproportionately. One cause is that subsidies are given to larger farms. A lot of the problems is that public policy is affected too much by special interests that don’t have issues like world hunger or the needs of small farmers in the US or abroad in mind.

Jo Luck

Jo Luck, CEO of Heifer International, started her talk by saying that you ”don’t have to be a scientist or a researcher, it takes all of us together,” including educators and teachers. Luck is a teacher by training.

Luck contracted a disease while traveling in Africa that has caused her to be sight-impaired. After the talk, I asked how long she has had this illness and she shared that over the past 20 months she has endured many surgeries and a lot of pain. As a student remarked while we were waiting to speak to Luck, so many of us complain or stay in bed when we have the sniffles. Luck is a role model to many of us who live comfortable lives, who have never slept on the ground or gone without food.

Luck said that her experience with this illness has not impacted her as negatively as it might because of some experiences she has had with blind individuals in Africa. She has worked with a blind family that once was shunned, that once had no dignity or self-worth, but who learned to farm, to tend animals, to plow and to plant, that regained their dignity through hard work. If they could persevere through their blindness then so can she.

What has made Heifer International so effective is that it is grounded on principles, called the 12 Cornerstones. These cornerstones echo not only the goals of the organization but also the goals of the people that Heifer International helps. Luck surveyed 200 people in 45 developing countries to see what was most important for them. We can think of many things we might expect to see on the list, such as running water, medicine, cars, and televisions, but the top ten included family, love, peace, spirituality, health, friendship, livelihood, justice, and dignity. These were consistent across economic, ethnic, and other factors. These commonalities can help us to better respond to needs in the US and across the world.

These principles appear in another way: recipients consider the animal a living loan. Once they are able to raise themselves out of poverty, families and individuals are quick to want to help others that are in the same situation that they were able to leave behind. This often includes passing on offspring of the animal to neighbors, but can also include monetary donations back to Heifer International to help families in other countries. Luck didn’t say it but the conclusion to this thought hung in the air. If these families who are just able to meet their food needs are able to find money to spare to help other families, what can we in the United States do?

Alan Koslow, community activist, vascular surgeon, and local radio show host, asked whether Heifer International focused on cows or if they provided other animals and how they worked around cultural sensitivities when it comes to animal choices. Luck responded that Heifer International originally provided just cows, but now they have a number of species, and the appropriateness of each species for each situation is carefully considered. For example, communities with little space might be encouraged to take guinea pigs. Some animals are more useful that others in that they provide more options for families. Buffalo and goats are called “7 M” animals becuse they can provide milk, muscle, money, materials, meat, motivation, and manure – such animals are particularly useful in helping families and communities move out of poverty. In a conversation after the event, Luck shared that Heifer International is committed to a system of agriculture that includes plants and animals, and as part of their efforts they offer not only animals but seeds and education.

Editor’s note: Check out the Biofortified photo page for photos of Frank and Anastasia with this year’s Laureates. Dr. Koslow recorded the lectures which will be available on his YouTube channel.

“The half-pint of nonfat chocolate milk with sucrose served to students at lunch will have 150 calories and 27 grams of sugar – the same caloric and sugar content as the old formula,” according to Schools switch sugars in chocolate milk in the San Fransisco Chronicle. From the same article:

Switching from high-fructose corn syrup to sucrose in the chocolate milk is nonsense, said Dr. Robert Lustig, a pediatric endocrinologist at UCSF. It’s not how the sugar is made that’s the problem, he said – it’s that Americans, and especially kids, are eating too much sugar, period.

“The difference between high-fructose corn syrup and sucrose, molecule for molecule or ounce for ounce, isn’t worth discussing. They are both equally dangerous,” Lustig said.

If you choose not to believe Dr. Lustig, check out Rule # 4 from Michael Pollan’s recent Food Rules, or more importantly, check out the text explaining the rule (emphasis added):

Avoid products that contain high-fructose corn syrup.

Not because high-fructose corn syrup (HFCS) is any worse for you than sugar, but because it is, like many of the other unfamiliar ingredients in packaged foods, a reliable marker for a food product that has been highly processed. … don’t fall for the food industry’s latest scam: products reformulated to contain “no HFCS” or “real cane sugar.” These claims imply these foods are somehow healthier, but they’re not. Sugar is sugar.

So, if sugar is sugar, what can actually be done to make school lunches healthier? To me, it seems that the problem is systemic.

In Florida, where I grew up, schools get some amount of funds from the state, but property taxes are the primary source of funding for schools. As far as I know, California’s schools are funded in the same way. California is worse off than Florida, though, after Prop 13 in 1978 capped property taxes at low levels (I learned about this from a member of DAMN while Karl and I were in California). Ideally, schools would be funded differently, but for now we’re stuck trying to do more and more with smaller and smaller budgets. Schools simply have to work within these cost constraints.

Instead of targeting one ingredient, why don’t parents work to find creative ways for schools to feed healthy meals to their children within the budget that exists?

Since their budgets for food are so small, schools can’t afford to pay staff to cook. Instead, they pay staff to reheat. I hadn’t really thought about this before I stumbled upon Mrs. Q’s blog Fed Up: School Lunch Project. She’s a teacher, and plans to eat school lunch every day in 2010. Mrs. Q says: “I think every child no matter how much money their family has deserves to eat quality food at school”, referring to the kids who may only get one meal per day.

Based on her pictures and descriptions, I don’t think I could do it. The one lunch that she’s had so far that really got to me is the one that’s pictured here: Day 16: peanut butter and jelly sandwich.

PB&J with fruit and milk is such a perfect lunch, so it’s really sad to see it bastardized into this sugary pre-packaged mess. It seems to me that the parents of this school, and of every school, should find out exactly what their kids are being served and come up with alternatives that still make budget. Can a school buy bread, peanut butter, and jelly and make the sandwiches for the same cost as these pre-packaged PB&J on graham crackers? Can they achieve the same calorie count and nutritional requirements with healthier ingredients? I bet the schools can, but maybe they just don’t have the time to find out, or the budget to hire someone to look into it.

There has to be at least one parent in San Fransisco who took time to protest corn syrup who has skills related to accounting. There has to be at least one parent in San Fransisco who took time to protest corn syrup who has skills related to creating menus. Where are these parents, and why aren’t they putting their skills to use? If they don’t have the skills needed, why don’t they contact undergrad and graduate students at local colleges to help them out? What a great resume builder or even thesis for a college student!

The school district employees responsible for nutritional quality of school meals are obviously open to discussion, judging by this quote from the SF Chronicle:

“My job is to provide nutritious meals that the students want to eat and that their parents want them to eat,” said Ed Wilkins, district director of Student Nutrition Services. “When a group of parents advocate for a particular change and it is feasible with the resources available to us to make that change, I will try to meet their demands.”

Have any commonly held beliefs about corn that you’d like to know more about? Let us know in the comments.

Myth: Huge amounts of the sizable US corn crop go to HFCS production. Here’s an example that sums up this idea from Grist: “The Big Corn People began to grow so much royally-subsidized GMO corn that they turned it into millions of gallons of high fructose corn syrup.”

It’s true, a portion of the US corn crop is used for HFCS production. It’s also true that corn syrup is cheap because the corn industry receives subsidies. But there’s a lot more to this story.

How is corn used?

Most of the US corn crop is used for animal feed. In 2006-2007, 5.6 billion bushels of corn were used for animal feed, 2.1 billion for exports, 2.1 billion for ethanol, 753 million for corn sweeteners, 272 million for corn starch, 190 million for corn foods (tortillas, cereal, etc), and 137 for alcoholic beverages, according to Iowa State University’s High Fructose Corn Syrup – How sweet it is (pdf).

It’s more than a little dishonest to blame the monocultures on HFCS, when so much of the crop is used for feed. Again, that’s 5.6 billion bushels of corn for animal feed versus 753 million bushels for sweeteners in 2007. We might also take a second look at ethanol.

Corn is used for so many things because it can be separated into fractions fairly easily. According to that same ISU Factsheet, a single bushel of corn (about 60 lbs) produces three primary products after wet milling:

• 1.6 lbs corn oil
• 13.5 lbs corn protein gluten animal feed
• 2.6 lbs corn gluten meal used for poultry feed, pre-emergent herbicide, and fur cleaner.

The remaining starch can then be used to produce one of three alternatives:

• 33 pounds of corn sweetener
• 32 pounds of cornstarch
• 2.5 to 2.7 gallons of ethanol or beverage alcohol

In other words, a bushel of corn can be used to make animal feed and either corn syrup or ethanol – not both. Over the years, the percentage of the crop that’s gone for sweetener or ethanol has changed a great deal. According to Table 27  – US use of field corn, by crop year (.xls), in 1991 7% of the corn crop was used to make sweetener, and 6.10% was used to make alcohol. In 2009, 5.78% of the corn crop was used for sweetener, while 35.82% was used for ethanol. Over the same years, the amount of corn harvested increased, so total corn syrup production did increase, but not much compared to ethanol.

If you’re looking to blame something for corn monocultures, it makes sense to turn first to animal products and then to ethanol… not to corn syrup.

How much does it cost?

Corn syrup is cheaper than sugar because of the climate in the US, tariffs on imported sugar, and because of corn subsidies. Sugar can be refined from two crops: sugar cane and sugar beets. Sugar cane is a tropical crop, and there aren’t many places in the US where it can be grown (see this map of US sugar cane acres in 2007 from the USDA to see just how few places). Sugar beets aren’t grown in many places in the US either (see this map of US sugar beet acres in 2007). Sugar cane and sugar beets both produce about 50% of US sugar, according to University of Florida Extension’s Overview of Florida Sugarcane.

Since there isn’t much sugar produced in the US, and due to the climate in the US we couldn’t produce much more even if we wanted to, we would need to import it from Brazil, India, or Europe. That could be a problem for locavores looking for sugar, but it’s definitely a problem for US sugar producers who want to stay competitive with producers overseas. Sugar producers have been successful in lobbying for high tariffs, so we don’t import much sugar. I don’t understand all the tariffs and other programs, but you can learn more at the USDA Foreign Agricultural Service’s US Sugar Import Program.

Since we can’t and don’t produce much sugar in the US, and there are trade barriers to importing sugars, it makes sense for food producers to look for an alternative sweetener. We have excellent climate and soils for corn (see this map of US corn acres in 2007), and it’s not that difficult to make sugar from corn starch.

More questions

I have to wonder if, in the absence of trade barriers, we would still have more corn syrup than corn sugar. Similarly, how much would the balance of sweeteners actually change if corn subsidies were removed? Since such a small amount of the crop is used to produce all the sweetener we need, I wonder if things would change much at all. Finally, even if we had enough sugar to meet consumer demand for sweet processed foods, would Americans actually consume any less total sugar than we do now? I think it wouldn’t change at all. As for what might change consumption of total sugars, we might consider subsidies on healthy (or at least healthier) foods and/or a tax on unhealthy foods and sodas. Here’s hoping.

http://www.hulu.com/embed/rhMlmAFNfiaz4y-ndokLIg

Modern Flourishes at Obamas’ State Dinner in the New York Times leaves me hungry. How wonderful: “the meatless menu included a mix of Indian and American favorites, including some African-American standards. Collard greens and curried prawns, chickpeas and okra, nan and cornbread”. Sounds like a lot of agricultural biodiversity to me! Cheers to Mrs. Obama for continuing to encourage Americans to consider healthy food options by setting such an exquisite example.

For the full menu, see this official press release from the White House (pdf). For pictures, you must see the slide show at the Times – there are very few pictures of the event online.

Karl, you’ll be happy to hear that the pears served for dessert were poached in honey from the White House’s own beehive!

Why am I bringing this up at Biofortified?

Sunshine quinoa salad by sonicwalker. Click the photo for the recipe. Via flickr.

The prepared food from Full Yield is not your typical prepared food. “The choices may include turkey chili, quinoa salads, salmon cakes, chicken tagine, mixed bean wraps and whole-grain peanut butter cookies,” according to the Times article. Employees in the program are encouraged to eat only Full Yield items or similar whole food meals prepared at home. In these few menu items I see a swath of biodiversity, things never seen in the typical American’s diet. If the people on the program can lean about (and enjoy!) food options that are more healthy and more varied, maybe they will continue to choose these healthy varied items when they are done with the program. Maybe, just maybe, this will lead to an increase in demand for small grains and legumes and a decrease in demand for foods like feedlot beef and white bread. Maybe, just maybe, this could lead to big changes in farming.

Michael Pollan, not surprisingly, is way ahead of me on this idea. His editorial Big Food vs. Big Insurance appeared in the Times in September. Pollan argues that the proposed changes in health insurance regulation, particularly requiring companies to take everyone (no more pre-existing conditions), will cause the health insurance lobby to start fighting for changes in things like the Farm Bill. Pollan suggests: “Insurers will quickly figure out that every case of Type 2 diabetes they can prevent adds $400,000 to their bottom line. Suddenly, every can of soda or Happy Meal or chicken nugget on a school lunch menu will look like a threat to future profits.”

I agree with Pollan that national food policies have an effect on what people eat, particularly when it comes to affecting how much food costs. When we subsidize commodity crops but don’t subsidize fruits and vegetables, we’re effectively reducing the cost to the consumer of processed foods and grain-fed meat. However, I don’t think a potential battle between “Big Food” and “Big Insurance” will lead to as much change as many of us would like to see.

Kid Cuisine photo by Matt, via the very odd but quite funny review of the product on the X-Entertainment blog.

Even if food subsides and policies are balanced to make healthy foods more affordable, people will still make the choices they’ve always made. Even if healthy foods become cheaper than unhealthy food, I’m not convinced that people will choose the cheaper option. People who grew up on box mac n’ cheese and “fun-shaped” chicken nuggets will not suddenly make and eat quinoa salad (maybe quinoa needs a snowboarding penguin?). But, if their workplace encourages them to try new foods, then maybe they’ll want to try them again.

We can’t just leave it up to a few scattered employers, though. We all have a responsibility, if we want farms to grow a larger variety of crops, to eat those crops, and to encourage our friends to eat them. Yum! Quinoa salad, anyone?

Eating locally is great, but since apples only ripen once per year, and they spoil relatively fast, that means we only have fresh apples for a short time each year. That’s too bad, since apples are a wonderful crunchy snack loved by kids and adults that provide health benefits from their fiber and antioxidants.

Shipping the apples from another place (like New Zealand) extends the time that apples are available, but shipping in refrigerated containers is expensive and results in greenhouse gas emissions, and we all know that those apples from far away just don’t taste as good as local ones.

Scab Resistant Selection RS103-130. Image from "Organic Production of a New Australian-bred Scab Resistant Apple in Queensland, Australia" by Middleton, et. al

There might be a way to have local apples available for a much longer time, as well as to have apples shipped in that use less energy and less pesticides!

After more than 20 years of work, researchers in Australia have developed apples that are resistant to black spot aka apple scab, a fungus that destroys fruit and leaves. The scab resistant line, called RS103-130, also stays fresh and crunchy much longer than typical apple lines. They achieved this through some initial crosses with a crabapple species followed by years of selective breeding. The crabapple provided RS103-130 with the Vf gene complex, which has been previously used to produce transgenic scab-resistant apples, which I’ll describe in more detail shortly. You can find the Australian patent for RS103-130 at FreePatentsOnline.

In 2005 and 2006, comparison experiments showed RS103-130 to have many benefits over Galaxy, a typical non-resistant cultivar (see chart below). According to Middleton, et. al, RS103-130 has off white flesh and medium texture, is crisp, sweet, low-acid, and juicy, with a mild flavor.

Chart from "Organic Production of a New Australian-bred Scab Resistant Apple in Queensland, Australia" by Middleton, et. al.

Because of all of these benefits and the reduced pesticides needed, organic apple growers in Australia are very interested in RS103-130. I wasn’t able to find any information on whether RS103-130 has been commercialized yet, or on how long it might be before I can try them. Apparently something happened with RS103-130 lately, because stories appeared in The Independent and in the New York Daily News last week. Neither of the stories say what prompted the coverage, nor does Treehugger, which picked up on the 1st two. If you know what’s new with these apples, please comment!

My first question upon reading these articles was: why has it taken twenty years?! Selective breeding can be painstaking, especially when you’re talking trees. There is a faster way…

The HcrVf2 gene from a wild apple confers scab resistance to a transgenic cultivated variety showed that the Vf gene can be inserted with biotechnology into apple varieties (in this case, the gene was inserted by Agrobacterium tumefaciens into the Gala apple cultivar). In the introduction of this paper from 2003, Belfanti et. al point out that:

the transfer of these genes by classical breeding to cultivated apples is difficult because of the long juvenile phase, self-incompatibility, and the impossibility of exactly reproducing the heterozygous state of cultivated varieties. Starting from the wild species Malus floribunda 821 carrying the Vf gene, breeders have developed several scab-resistant apple cvs. (2), but not one has met with commercial success. Indeed, when compared with such commercially popular cvs. as Golden Delicious and Gala, the main horticultural and fruit-quality traits of these scab-resistant cvs. are notably different and undoubtedly less acceptable.

Using biotechnology, the researchers were able to confer scab resistance in one generation. In this paper, the authors don’t mention any increase in lifespan for the fresh apples – I’ll look on Web of Science for more info tomorrow. I do appreciate that the authors are hopeful for the future of apple biotech.

The cloning of an apple scab resistance gene represents the basis for further investigation of the resistance mechanism. It also represents a step toward a gene therapy (restoring resistance where lost) of the scab-susceptible cvs. that currently dominate the apple industry. This strategy will allow the transfer of resistance from a wild apple species to any commercial apple genotype while maintaining the horticultural and fruit-quality traits growers and consumers prize most. It may also be possible to achieve greater resistance durability by the simultaneous transfer of several resistance genes from wild apple species. Going one step further, it may be possible to use apple promoters and novel techniques that, by eliminating selective marker genes (38, 39), generate transgenic varieties without any foreign genes and, hence, may make genetically modified plants more acceptable to growers and consumers alike.

I’m particularly interested that Balfanti et. al mentioned cisgenics, although they didn’t use the term. There is potential to insert genes like Vf into many varieties of apples, meaning that cultivars developed for specific microclimates may be quickly made resistant to scab (and potentially given a longer shelf life) without any loss of their other traits. This is a good example of how biotechnology and breeding can have the same results – get a gene into a cultivar – although one takes much longer than the other.

Corn earworm larva by W. Cranshaw.

One of the most interesting of these native traits is what Kevin calls FACE (fall armyworm corn earworm). This trait, which confers resistance to armyworm and earworm, originates in tropical germplasm. Kevin is hoping to provide an alternative to Bt. One benefit of using a non-biotech trait is reduced cost. However, even native traits are not without added cost. This isn’t a single gene trait, so it’s extremely difficult to move out of the tropical lines. While the trait isn’t ready for licensing and distribution, it is very promising so far. Plants with the trait survived the entire growing season without damage from worms and without insecticide in Puerto Rico. This has great potential for the organic sweet corn market.

Kevin gave a pre-tasting lesson to the tasters.

Currently, Kevin has a client asking for hybrid sweet corn varieties suitable for the fresh market, such as roadside stands and farmers’ markets. He breeds with his own genetic resources, but grows commercial hybrids like Vision alongside his experimental hybrids as checks. In the breeding program, he crosses promising (read: tasty) inbred lines to many other inbred lines, looking for the best hybrids. Just as in any other hybrid breeding program for any species, some inbreds combine better than others. He is also developing some improved open pollinated varieties for specialty markets.

The two most important traits in the selection program are taste and regional adaptability. He’s planted the same trial in at least three locations across the US to see how the hybrids fare with different weather and soil conditions.

The first round of taste testing is done in the field. This may seem strange, because most people eat sweet corn after it’s been cooked at least a little, but field tasting saves a lot of time and effort. Kevin can eliminate hybrids that just aren’t worth the bother of harvesting and cooking. Also, cooking can introduce a lot of variability – the time from harvest to pot, the temperature of the water, cooking time, and characteristics of the water such as sulfur content. However, there are some drawbacks to raw tasting. Cooking denatures some proteins and deactivates some enzymes.Leaving these intact can affect the flavor of the corn – positively, in my opinion. The enzymes, however, can cause severe digestive discomfort. My iron stomach did not fail me – perhaps I have resistance due to all of the raw veggies that I eat?

Testing “ease of silking”.

The tasting process starts with benchmarks. Kevin gave the tasters a range of samples from very sweet to not sweet so we knew where to place the unknown samples on a scale from 1 to 9 (with 9 being the sweetest). The sweetness isn’t just due to sugar; it can also be affected by molecules that taste sweet like the amino acid proline. Some of these molecules can be degraded through cooking, which is why it’s so important to avoid overcooking sweet corn.

The sweet flavor of sweet corn is primarily caused by mutations in one of two genes: sugary1 and shrunken2. Both genes affect how sugar and starch are metabolized in the kernels. Their effects are different enough that you can taste it. Sweetness conferred by shrunken lasts well into the season, but sweetness conferred by sugary will quickly disappear as sugars are converted into starch. There is a third gene affecting sweetness that is found in some tropical germplasm called brittle, but it’s not yet made the rounds into non-tropical lines. All of the mutations are recessive, which means that both of the inbred parents need to be homozygous for at least one of the sweetness conferring mutations in order to have the sweet phenotype appear in the hybrid. Finally, some lines carry a mutation in the gene sugary enhancer that improves tenderness and extends the length of time that sweetness lasts when it is present in the same line as sugary.

All of these genes interact with each other and with other genes to provide an endless range of sweetness from sickly sweet to barely sweet at all. Also, the combinations of mutant alleles have different effects on traits like germination rate and seed development.I’m not that familiar with the biochemical workings of sweetness in sweet corn – so if you’d like to learn more, you might want to visit Karl, who works with sugary enhancer, over at Inoculated Mind.

The appearance of the ears is very important to the success of any particular sweet corn hybrid, because that’s what people first see at the farm stand. One part of appearance is color. People in some areas of the US, Latin America, and Africa prefer white corn. They associate yellow corn with animal feed. People in other areas prefer bi-color corn with white and yellow kernels.

Cuitlacoche by Monica Ortiz Uribe for NPR.

Another aspect of appearance is how the leaves envelop the ear. Ideally, the leaves will cover the end of the ear, which looks nice as well as being a deterrent to insects trying to get to the kernels. The leaves and silks must come off easily in shucking, and the leaves must have just the right length of “flags” at the tips. Susceptibility to insects and smut is another very important part of appearance. Nothing turns customers away more than worms in the ears.Smut can damage ears and is very unattractive as well (except in particular markets where smut, or cuitlacoche, is actually desired in its own right).

We also graded the tenderness and texture/creaminess of the corn. Tenderness includes how difficult it is to separate the kernels from the cob and how hard it is to bite into the pericarp, or outer layers, of the kernels. Texture includes the fat and water content of the kernels, which leads to a creamy or watery feeling as the kernels burst in your mouth. These traits can be affected by cooking but testing them raw still provides valuable information. Kevin tests many other traits on his own.

Yum! Here, I’m tasting my favorite of all of Kevin’s hybrids.

I was amazed at how different each ear could be, even within the same line. Differences within lines can be due to the age of each ear and the type of pollen that happened to fertilize a particular ear, among other factors.

All in all, tasting sweet corn with Kevin was a great experience, and not just because I got to have some delicious corn. This experience helped me to appreciate all the work and knowledge that goes into breeding a new crop line. I hope that reading this post helps you to appreciate it as well.

A few more incidental tidbits that came up (you never know what you’ll learn when you’re around a plant breeder):

Golden Cross Bantam, a hybrid resistant to Stewart’s wilt and containing the sugary mutation, has been around since the 1940s (but wasn’t part of the taste test). Illini super sweet was the first hybrid sweet corn to contain the shrunken mutation, and has been around since the early 1970s. Commercial sweet corn hybrids remain popular and in use for a long time, much longer than field corn hybrids, which last about 4 years before being replaced by hybrids with additional improvements. This may be because people, once they find a hybrid they love, will continue to seek out the same sweet corn year after year.

Each species has a different heirloom state, depending on their natural state of fertilization – open pollinated, obligate selfing, etc. Heirloom varieties of corn are open pollinated because that’s the natural state of the species. Inbred lines and the hybrids that are produced by crossing them remain constant, but open pollinated lines are always changing.

Talk of Kevin’s FACE (fall armyworm corn earworm) lines led to an interesting discussion of Bt. I need to research this a bit, but wanted to share the information and get comments. Instead of planting separate non-Bt refuges alongside Bt corn fields to guard against insect resistance, seed companies can mix the non-Bt seed right in. If there is one Bt gene in the seed, they are supposed to provide for 25% non-Bt seed. If there are two or more Bt genes in the seed, the seed companies argue that 5% is enough because it is less likely that insects could become resistant to two types of Bt. The problem is that seed with the Bt trait can get mixed into the non-Bt seed, so that the final percentage of non-Bt seed in the mix is lower than it should be. Seems to me that the solution is easy: conduct tests to see what is the lowest effective percentage, then mandate a slightly higher percentage, and conduct spot checks on lots of seed to be sure that seed companies comply.

In maize, % leaf area infected by fungus at mid silking = ½ % yield loss for grey leaf spot because damage is internal to the leaf. For example, if 20% of leaf area is infected at time when plants are at mid silk, the yield will be approximately 10% lower than if it was not infected. However, rust causes eruptions at the leaf surface, so there is water loss, thus a greater yield loss.

Many thanks to Kevin for the experience and for proofing this post, to Tina Paque for taking photos of the tasting, and to the other tasters for making this a fun and educational experience!