Plant genetics

Plant genetics is the study of genes, genetic variation, and heredity specifically in Plants. It is generally considered a field of biology and botany, but intersects frequently with many other life sciences and is strongly linked with the study of information systems. Plant genetics is similar in many ways to animal genetics but differs in a few key areas.Domingo, José L.; Bordonaba, Jordi Giné (2011). 'A literature review on the safety assessment of genetically modified plants' (PDF). Environment International. 37 (4): 734–742. doi:10.1016/j.envint.2011.01.003. PMID 21296423.Pinholster, Ginger (October 25, 2012). 'AAAS Board of Directors: Legally Mandating GM Food Labels Could 'Mislead and Falsely Alarm Consumers''. American Association for the Advancement of Science. Retrieved February 8, 2016. Plant genetics is the study of genes, genetic variation, and heredity specifically in Plants. It is generally considered a field of biology and botany, but intersects frequently with many other life sciences and is strongly linked with the study of information systems. Plant genetics is similar in many ways to animal genetics but differs in a few key areas. The discoverer of genetics was Gregor Mendel, a late 19th-century scientist and Augustinian friar. Mendel studied 'trait inheritance', patterns in the way traits are handed down from parents to offspring. He observed that organisms (most famously pea plants) inherit traits by way of discrete 'units of inheritance'. This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Much of Mendel's work with plants still forms the basis for modern plant genetics. Plants, like all known organisms, use DNA to pass on their traits. Animal genetics often focuses on parentage and lineage, but this can sometimes be difficult in plant genetics due to the fact that plants can, unlike most animals, be self-fertile. Speciation can be easier in many plants due to unique genetic abilities, such as being well adapted to polyploidy. Plants are unique in that they are able to produce energy-dense carbohydrates via photosynthesis, a process which is achieved by use of Chloroplast|chloroplasts]]. Chloroplasts, like the superficially similar mitochondria, possess their own DNA. Chloroplasts thus provide an additional reservoir for genes and genetic diversity, and an extra layer of genetic complexity not found in animals. The study of plant genetics has major economic impacts: many staple crops are genetically modified to increase yields, confer pest and disease resistance, provide resistance to herbicides, or to increase their nutritional value. The earliest evidence of plant domestication found has been dated to 11,000 years before present in ancestral wheat. While initially selection may have happened unintentionally, it is very likely that by 5,000 years ago farmers had a basic understanding of heredity and inheritance, the foundation of genetics. This selection over time gave rise to new crop species and varieties that are the basis of the crops we grow, eat and research today. The field of plant genetics began with the work of Gregor Johann Mendel, who is often called the 'father of genetics'. He was an Augustinian priest and scientist born on 20 July 1822 in Austria-Hungary. He worked at the Abbey of St. Thomas in Bruno , where his organism of choice for studying inheritance and traits was the pea plant. Mendel's work tracked many phenotypic traits of pea plants, such as their height, flower color, and seed characteristics. Mendel showed that the inheritance of these traits follows two particular laws, which were later named after him. His seminal work on genetics, “Versuche über Pflanzen-Hybriden” (Experiments on Plant Hybrids), was published in 1866, but went almost entirely unnoticed until 1900 when prominent botanists in the UK, like Sir Gavin de Beer, recognized its importance and re-published an English translation. Mendel died in 1884. The significance of Mendel's work was not recognized until the turn of the 20th century. Its rediscovery prompted the foundation of modern genetics. His discoveries, deduction of segregation ratios, and subsequent laws have not only been used in research to gain a better understanding of plant genetics, but also play a large role in plant breeding. Mendel's works along with the works of Charles Darwin and Alfred Wallace on selection provided the basis for much of genetics as a discipline. In the early 1900s, botanists and statisticians began to examine the segregation ratios put forth by Mendel. W.E. Castle discovered that while individual traits may segregate and change over time with selection, that when selection is stopped and environmental effects are taken into account, the genetic ratio stops changing and reach a sort of stasis, the foundation of Population Genetics. This was independently discovered by G.H. Hardy and W. Weinberg, which ultimately gave rise to the concept of Hardy-Weinberg equilibrium published in 1908. For a more thorough exploration of the history of population genetics, see History of Population Genetics by Bob Allard. Around this same time, genetic and plant breeding experiments in maize began. Maize that has been self-pollinated experiences a phenomena called inbreeding depression. Researchers, like Nils Heribert-Nilsson, recognized that by crossing plants and forming hybrids, they were not only able to combine traits from two desirable parents, but the crop also experienced heterosis or hybrid vigor. This was the beginning of identifying gene interactions or epistasis. By the early 1920's, Donald Forsha Jones had invented a method that led to the first hybrid maize seed that were available commercially. The large demand for hybrid seed in the U.S. Corn Belt by the mid 1930's led to a rapid growth in the seed production industry and ultimately seed research. The strict requirements for producing hybrid seed led to the development of careful population and inbred line maintenance, keeping plants isolated and unable to out-cross, which produced plants that better allowed researchers to tease out different genetic concepts. The structure of these populations allowed scientist such a T. Dobzhansky, S. Wright, and R.A. Fisher to develop evolutionary biology concepts as well as explore speciation over time and the statistics underlying plant genetics. Their work layed the foundations for future genetic discoveries such as linkage disequilibrium in 1960.