Semidwarf varieties of both wheat and rice helped turn entire countries once starving for food into leading exporters of food. Semidwarf varieties can also contribute toward sustainable agriculture.
A wheat variety that expresses some degree of height reduction directs precious resources, such as water and fertilizer, primarily to that part of the plant consumed by humans, and not to the vegetative parts. Very simply, most of the wheat storage protein genes can be found on different chromosomes than the Rht genes.
Thus the two traits are not inherited together, and, further, as already mentioned, many modern varieties of wheat grown today in the United States do not possess an Rht gene. On a final note, starch and protein contents in wheat occur in inverse proportions, and thus, as one fraction increases on a percentage basis, the other decreases. Depending on the end-use of wheat flour, some wheat varieties are higher in protein and thus gluten , while others are lower in protein.
The prevailing types of gluten molecules may vary depending on the end-use. For flour used in confectionery products, more mellow gluten and lower gluten content more starch are preferred, whereas, for certain types of bread and pasta, a stronger gluten and higher gluten content are preferred. The desired amount and type of gluten in a wheat crop is determined not only by the variety but also by the environmental conditions weather, soil, etc.
With such inherent variability and fluctuation in the amount, or kind, of gluten that enters our daily diet, and with no scientific evidence that gluten content has systematically shifted with wheat breeding Kasarda, D. Genetic engineering is often used in combination with traditional breeding to produce the genetically engineered plant varieties on the market today. For thousands of years, humans have been using traditional modification methods like selective breeding and cross-breeding to breed plants and animals with more desirable traits.
For example, early farmers developed cross-breeding methods to grow corn with a range of colors, sizes, and uses. Most of the foods we eat today were created through traditional breeding methods. But changing plants and animals through traditional breeding can take a long time, and it is difficult to make very specific changes.
After scientists developed genetic engineering in the s, they were able to make similar changes in a more specific way and in a shorter amount of time. PDF KB. Circa BCE Humans use traditional modification methods like selective breeding and cross-breeding to breed plants and animals with more desirable traits.
Some plants looked strong and healthy while others looked, well, pathetic. These few rows were the second season of an experiment. While on a trip to Latin America, our farmer friend had bought a handful of beans at a village market and stuffed them in his pocket.
He went on to explain that instead of eating those beans, he planted the handful from his pocket in the ground just to see what would happen. Low and behold, he had a few germinate and grow to produce new seed. Just a few. This crop we were looking at was the second season of growth, selected from those few beans that grew the first year. Now he had two full rows and greatly improved germination.
We were witnessing an ancient practice at work. His beans are adapting to the climate and soil with a little help from the farmer. The farmer selects the best and replants them the next season. Those seeds grow and the process begins again. When this is done repeatedly, successive generations of a particular plant can look very different from the plant's ancestors. That's what's happened with modern wheat, which is shorter, browner, and far higher-yielding than wheat crops were years ago.
Dwarf wheat and semi-dwarf wheat crops have replaced their taller cousins, and these wheat strains require less time and less fertilizer to produce a robust crop of wheat berries. However, a study published in the Journal of Agricultural and Food Chemistry reported that there's not really any more gluten in modern wheat than there was in s-era wheat.
Studies do show a significant increase in the incidence of celiac disease over the last several decades. However, it's not at all clear why the number of people affected by these two conditions might be rising. Donald D. Kasarda, the U. Department of Agriculture scientist who authored the study on s wheat, wonders whether it's possible that increased consumption of wheat in recent years—rather than increased gluten in the wheat actually consumed—might be in part to blame for increased incidence of celiac disease.
He also says the use of wheat gluten as an ingredient in processed foods might contribute. However, he says that much more research must be made to evaluate these other possible contributors.
However, no one really knows why celiac disease and possibly gluten sensitivity might be affecting more people. There's one thing that's certain, though: Genetically modified wheat can't be to blame.
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