Gardening

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Sowing seeds of change

It is spring and a gardener’s thoughts are on the soil and what to plant.  Vegetable gardeners may be planning their garden, what to sow indoors now, direct sow into the garden later, and what to plant as transplants.  There is a lot to consider, but it all comes back to the seeds: those tiny self-contained units of possibility. The subject of seeds is a complex one for today’s gardener, but it’s not really new as people have been manipulating seeds for thousands of years by selecting plants for their desirable qualities. Through careful saving of seed, new plants developed as the ancestors of what we have today as a wide array of vegetables.

Until the early 20th century, farmers allowed the wind and insects to do the pollinating (called open-pollination). The results were often variable, but since farming was still small scale, that was not the important point it was about to become.  In the early 1900s a scientist named George Harrison Shull began to study open-pollination and found that when the resulting plants were healthier, taller and more productive than the parent plants, these plants could be cross-pollinated in a controlled environment with similar exceptional plants and the offspring would exhibit exceptional qualities that Shull termed “hybrid vigor.”  This was a huge discovery for farmers as it meant that plants were uniform in size, health and yield and it came at a time when farm machinery was becoming commonplace so farmers could easily grow more crops to feed an increasing population. Agriculture was changing.

In the 1920s scientists were interested in affecting change in plants by exposing them to radiation or chemicals that would cause genetic mutations resulting in resistance to disease, sweeter fruit or growth habits that improved the quality of the crop.  Many of the fruits, grains and vegetables that we find at our markets today are the result of “mutation breeding,” but scientists have long since moved on to other techniques.

Perhaps the most debated technique came about in the 1980s with the dawn of genetic engineering. Scientists developed sophisticated tools to change the plants’ DNA by adding, removing or altering genes.  Food engineered this way is called a genetically modified organism or GMO. By the 1990s the first crops were on the market and today they include corn, soybeans, hay, wheat, rice and cotton.  Many of these crops are used in the production of processed food, so profit is a large factor. 

Fruits and vegetables are less likely to become GMO’s as the profit margin is not big enough to be interesting to large seed companies who would have to pay for safety tests and federal regulatory procedures mandatory for sale approval. 

There has been much discussion about GMO’s and their health effects over time; and while the public is cautious about the technology, all plant breeding technologies have pros and cons.  From the farmer’s perspective there are cost and environmental savings to plant GMO corn seed that is resistant to the herbicide Roundup. A farmer plants corn seed and several weeks later he applies the weed killer and he is done. Thus, fewer dollars spent on chemicals and far less chemical exposure for the farmer and the environment, and no labor for weeding.

The use of GMO rice seed in third world countries could combat vitamin A deficiencies, but can farmers in those countries afford the higher cost of the seed?  While the health organizations of the world and scientists are saying that GMO crops bear no ill health effects to humans, the public is not entirely convinced. Fortunately, there is some encouraging news on the horizon.

The newest generations of plant breeders blend traditional farming and genetic analysis to help shape new plants.  Harry Klee, a tomato breeder at the University of Florida, has been working to develop tomatoes that meet everyone’s criteria for yield, shipping, shelf life and taste.  Using the latest technologies that employ genetic analysis and genome sequencing, Klee is breeding heirloom tomatoes with modern tomatoes so he is using the current technologies and older methodologies to create crossbreeds with superior qualities.  Two varieties have been released by the University: ‘Garden Gem’ and ‘Garden Treasure’ and they are waiting for licensing to a seed company for large scale distribution.

Cornell University professor Thomas Bjorkman and colleagues have been working to develop a broccoli that grows well in warmer climates.  Broccoli is a cool weather crop and most nutritious when eaten soon after harvest so getting a summer crop of broccoli from farm to table quickly is a challenge for farmers.  While the technologies are improving and getting cheaper, the capital investment needed to produce large quantities of seed and marketing them is very expensive. 

Also from Cornell is plant breeder Michael Mazourek who works with peppers.  His method is not genetic engineering as there is no direct manipulation of DNA.  Genomes are sequenced and the data analyzed to build databases that link various genes and traits.  As young plants develop, their genes are analyzed and some are chosen to grow out in the field and others used for breeding purposes. To the average person this is far less “franken” then GMO’s, and while in many ways this is a “brave new world” that might surpass Aldous Huxley’s wildest dreams, it may also hold the key to newer versions of fruits and vegetables that will be extraordinarily nutritious and may help those who eat them to fend off illness and disease. A real twist on the old adage “you are what you eat” that simply starts with a seed.
 

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