Hexaploid Wheat: Evolution, Domestication, Dissemination, US commercialization, and Molecular characterization
Wheat is one of the major food crops in the world, which provides 532 kcal/capita/day (http://faostat.fao.org). World production of wheat is about 670 M tonnes, which is only behind maize (872 M tonnes) and rice (720 M tonnes) (http://faostat.fao.org) whereas the US is the third largest wheat producer in the world (http://faostat.fao.org). Wheat group comprise of 13 diploid and 18 allopolyploid species (12 tetra and 6 hexa) (Feldman et al. 2012), where hexaploid wheat is the most cultivated class throughout the world (Faris 2014). Hexaploid wheat (bread wheat) is known as the allohexaploid (2n=6x=42, BBAADD), because it is derived from the diploid species via convergent evolution (Faris 2014 and Feldman et al. 2012). Hexaploid wheat consist of winter and spring wheat, which mainly differed by vernalization governed by vrn (vrn1, vrn2) genes (Taiz and Zeiger 2002, Doebley et al. 2006).
Wheat has 21 pairs of homologous chromosomes and seven homoeologous chromosome group, which possess high level of similarity (Feldman et al. 2012). There are various genetic changes such as elimination of low or high copy DNA sequences, elimination
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2007; Peng et al. 2011). Tough glume do not allow free – threshing. However, two genes Tg22BTg12Dassociated with the tenacity of the glume has been reported (Faris 2014). Till now there is no Tg gene has been reported on the A genome. The single recessive gene sog has been reported, which confines the soft glume trait in the free- threshing mutant of domesticated einkorn wheat T.sinskajae (2AmS) (Taenzler et al. 2002; Sood et al. 2009; Faris 2014) .Exact relationship between the tg/ sog is not well defined yet (Faris 2014). Studies performed by Nalam et al. (2007) indicates that possibility of two paralogous regions on chromosome 2DS for
This diploid zygote, which undergoes meiosis, forms eight haploid ascospores. The ability of Sordaria to make 8 haploid ascospores is what makes it unique and important for the laboratory exercise done in the lab. The laboratory performed had as a purpose to determine the change in crossing-over frequency or the also called map distance under different environmental conditions in Sordaria sp. This paper has a purpose to analyze, with the help of scientific research, the results obtained in the laboratory exercise. To investigate the crossing over in Sordaria sp., a cross between two mutant strains was performed.
In a good year all or most of them will thrive and give you wheat. But in a bad year a spate of high winds may take down the tallest stalks and leave standing at the harvest time only, say, the 10 percent of the crop that had a “shortness” gene. And if that wheat comprises your winter’s supply of bread, plus the only seed you’ll have for next year’s crop, then you’ll be almighty glad to have that small, short harvest. Genetic diversity, in domestic populations as well as wild ones, is nature’s sole insurance policy. Environments change: Wet years are followed by droughts, lakes dry up, volcanoes rumble, ice ages dawn. It’s a big, bad world out there for a little strand of DNA. But a population will persist over time if, deep within the scattered genetics of its ranks, it is literally prepared for anything. When the windy years persist for a decade, the wheat population will be overtaken by a preponderance of shortness, but if the crop maintains its diversity, there will always be recessive aspirations [i.e., recessive genes] for height hiding in there somewhere, waiting to have their day (97-98).
Modern biotechnology was born at the hands of American scientists Herb Boyer and Stain Cohen, when they developed “recombinant deoxyribonucleotide, (rDNA), [1] for medicinal purposes. Subsequently, biotechnologists started genetically engineering agricultural plants using this technology. A single gene responsible for a certain trait, from one organism (usually a bacterium) is selected altered and then ‘spliced” into the DNA of a plant to create an agricultural crop consisting of that...
Food is an essential part of everyday life without it one could not survive. Every day we make choices on what we put in to our bodies. There are countless varieties of food to choose from to meet the diverse tastes of the increasing population. Almost all food requires a label explaining the ingredients and the nutritional value allowing consumers to make informed decisions on what they are consuming. However, many may not be considering where that food is coming from or how it has been produced. Unfortunately, there is more to food than meets the eye. Since 1992, “ the U.S. Food and Drug Administration ruled, based on woefully limited data, that genetically modified foods were ‘substantially equivalent’ to their non-GM counterparts” (Why to Support Labeling). GM food advocates have promised to create more nutritious food that will be able to grow in harsh climate conditions and eventually put an end to world hunger in anticipation of the growing population. There is very little evidence to support these claims and study after study has proven just the opposite. GM crops are not only unsafe to consume, but their growing practices are harmful to the environment, and multinational corporations are putting farmers out of business.
Six weeks previous to the conductance of this lab, Biology 108 section,planted wheat and mustard plants according to table#1 on page 3 of the Principles of Biology 108 Lab Manual . This table depicts all of the total pots and number and type of seeds planted in the pots. It accounts for the experiments of the intraspecific competition and interspecific competition. Replicates of each pot were planted to add precision and more acceptable statistics. Therefore, there were 40 pots, that is, 20 treatments conducted twice(Ciara, 1993).
Genetic engineering or genetic modification of corn refers to using molecular techniques or other similar techniques of biotechnology to add slight quantities of chromosomal material to the atomic structure and composition of corn, to protect it against infestation by pests, harm caused by herbicides or to increase its quality 4. In general, genetically modified corn is wired to resist herbicides and to produce its own insecticide. The trait in corn which tolerates herbicides is produced using tissue culture selection and a chemical called mutagen ethyl methanesulfonate 1. The trait in genetically modified corn that produces insecticide has a certain protein that is poisonous to some insect pests called Bt Toxin, hence the reason why genetically modified corn is also called Bt corn 3.
Wheat likes to grow in 70 to 75 F temperatures. It needs lots of sunshine, low humidity and 12 to 15 inches of rain. “Moderate warming and more carbon dioxide in the atmosphere may help some plants to grow faster. However, more severe warming, floods, and drought may reduce yields” (Climate Impacts on Agriculture and Food Supply). This means crops can produce more wheat when there are good temperatures and carbon dioxide. Less wheat is produced when there is bad weather such as floods or very little rain. According to the website, “Dealing with drought could become a challenge in areas where rising summer temperatures cause soils to become drier.” (Climate Impacts on Agriculture and Food Supply). Dry soil destroys wheat crops. In summary, temperatures and water are very important to soil because it affects how much wheat is produced. So, without good temperatures, rain, and soil there wouldn’t be enough wheat to produce
For thousands of years 2, humans have been selecting the seeds of plants with certain desirable genetic traits to plant the following years crop. For years upon years, growers have identified and cultivated useful plant variants through selective breeding and environmental alterations. Corn, as it is known today, is nothing like it was a thousand years ago. Gregor Mendel, the "Father of Genetics", wrote his first major paper on genetics in 1865 where he puts into words wha...
Vitosh, M. L. "Wheat Fertility and Fertilization." Michigan State University Field Crop Team. Department of Crop and Soil Sciences, n.d. Web. http://fieldcrop.msu.edu/wheat/ 23 Jan. 2014.
Breeding for grain Fe and Zn enrichment requires sufficient genetic variability for grain micronutrient in the available germplasm as well as the information on genetic control of grain micronutrient content in the seed. Also reported significant positive association between two traits (Reddy et al., 2010) indicates the common genomic region or genes or biochemical pathway involved in expression of the trait. Hence the knowledge of phenotypic association between the traits gives basic idea for simultaneous improvement of the trait. Apart from this, understanding the environment is considered important in breeding for traits that depends on many factors (Campbell and Lafever, 1980; Ghaderi et al., 1980; Fox and Rosielle, 1982; Yau et al., 1991, Joshi et al., 2007). Proper characterizing and understanding of locations is very important for screening breeding lines of greater concentration of zinc and iron in the grain (Ortiz- Monasterio et al., 2007).
Barley is a very important grain in the world today. It is very versatile in every way. It has been well adapted through its evolution. It has a very mysterious and much debated beginning. Now however, barely has become well known and so have its many uses. Barley, which is of the genus Hordeum, is a cereal that belongs to the grass family Poaceae. Barley has many different varieties. The most common is Hordeum vulgare, which is a six-rowed type of barley that has a spike notched on opposite sides with three spikelets on each notch. At each notch there is a flower or floret that later develops into a kernel. Hordeum distichum is a two-rowed type of barley that has central florets producing kernels and it has lateral florets that are sterile. Lastly there is Hordeum irregulare which has fertile central florets and different arrangements of sterile and fertile lateral florets. This is the least cultivated species of the three main forms (2).
around the world will eventually suffer the consequences of this new and porly examined science. What should concern every
During prophase I, homologous chromosomes pair and form snynapses. The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic recombination becomes apparent. The bivalent has two chromosomes and four chromatids, with one chromosome coming from each parent.
Meiosis, or reductional division, is the process during which exchange of genetic material between the homolog chromosomes (crossing-over and recombination) takes place and such a division of the genetical material occurs the four daughercells.
Wheat, as a plant, has a long history of being a crop for food, but the technology for it has been behind soybeans and corn. Wheat, in the future, will be at the top of its production by 2020 with new hybrids coming from many of the major companies. With the growing population of the world, the wheat hybrids need to be more productive to keep up with the rapid growth rate of the world and the decreasing farmland acreage.