Folic acid is an important vitamin for human nutrition, obtained primarily from plant sources. However, important vegetables usually have a lower concentration of this vitamin. Therefore, tomatoes, an important vegetable, were developed to improve folate content by overexpressing mammalian synthetic cyclohydrolase I GTP (GTPCHI) and the aminodeoxychorismate synthase gene (ADCS) of Arabidopsis, thereby increasing folate content by 25-fold in tomato fruits (de la Garza et al, 2004; de la Garza et al, 2007). Later, rice seeds with high folate levels were biofortified by developing Arabidopsis, GTPCHI and ADCS genes with their seed-specific overexpression (Storozhenko et al., 2007). The socio-economic barrier has not yet approved the commercial release of folic acid-enriched CMGs for commercial cultivation (Blancquaert et al., 2014). Plants such as soybeans have also been experimented with a technique to increase the active α-tocopherol readily available in seeds due to the high edibility worldwide. Soybean was transformed by overexpressing the gamma-tocopherol methyltransferase gene isolated from Perilla frutescens with a 10.4-fold increase in α-tocopherol (Tavva et al., 2007). Previously, a similar Arabidopsis gene had also been developed in lettuce to increase tocopherol levels (Cho et al., 2005). However, results from field trials with CMGs with enhanced vitamin E supplements were not sufficiently consistent with non-GMCs (Harrigan and Harrison, 2012).
GM crops with improved vitamin A content in cereal crops, especially wheat, rice and maize, which are staple foods in several countries in Africa and South Asia, can significantly reduce mortality due to vitamin A deficiency. The introduction of Golden Rice in 2000 marked the new era of GMCs with better incorporation of nutrients. Since rice is the staple food worldwide, the incorporation of whole genes from the beta-carotene synthesis pathway into the rice endosperm was intended to solve the main problem of vitamin A deficiency in several underdeveloped and developing countries (Ye et al., 2000). The genes phytoene synthase (Psy) and lycopene beta-cyclase were fused into the rice genome by Narcissus pseudonarcissus with phytoene desaturase from Erwinia uredovora (Beyer et al., 2002). However, the introduction of Golden Rice, like all other GMCs, is blocked from being placed on the commercial market unless researchers have demonstrated its improved benefits for existing varieties and the safety of human consumption. However, before Golden Rice was marketed, another Golden Rice 2 variety from Paine et al. (2005). This strain could synthesize 23 times more beta-carotene by incorporating phytoene synthase from corn in addition to E.
Uredovora carotene desaturase gene from Golden Rice. Golden Rice has been approved by Australia, New Zealand, Canada and the United States (Lynas 2018). In addition, the Philippines also approved the use of GR2E Golden Rice for Food or Processing (www.irri.org) in 2019 (IRRI, 2019). Rice was also produced with iron biofortification. Goto et al. (1999) transformed the rice genome into improved iron (Fe) content in rice seeds. The improved transgenic rice was produced by fusing a soybean-derived ferritin gene soyferH1 with the rice endosperm-specific glutelin promoter to enhance Fe accumulation in rice seeds. The expression of the ferritin gene in rice seeds increased Fe accumulation as well as Zn concentration. Transgenic rice retained its nutritional properties even after grain polishing (Vasconcelos et al., 2003).
However, the global market launch of fortified rice is still in the process of placing on the global market due to the continued partial acceptance of golden rice worldwide (De-Xian Kok et al., 2018). Successful commercial plant breeding operations were established from the end of the 19th century. [clarification needed] Garton`s Agricultural Plant Breeders in England was founded in the 1890s by John Garton, who was one of the first to commercialize new varieties of agricultural crops produced by cross-pollination.  The company`s first introduction was Abundance Oat, one of the first agricultural cereals to be selected from controlled crossing and marketed in 1892.   With the slow pace of transgenes for insect and herbicide resistance, GMCs to improve nutritional quality can not only improve farmers` incomes, but also provide a sustainable food source without the need for additional supplements. However, unlike other GMCs, plants with improved nutrient content are adopted a little more slowly as they are produced for exclusive consumption. However, with the introduction of GM maize for a higher lysine content, it is hoped that other crops will soon enter commercial markets. In plant breeding, QTL analysis can be coupled to MAS, allowing breeders to better select not only offspring, but also potential parents carrying desirable genes for traits of interest. However, the marker density of many cards created in this way is not very high. In addition, since only two parents are involved in crossbreeding, it is possible that they still share many genetic alleles. This may be beneficial when creating the original map, as fewer markers (i.e. less confusion in mapping) would be needed to cover the genome, albeit at a lower resolution (i.e.
approximate mapping30). However, this can decrease the apparent length of the map and reduce the accuracy of mapping, especially minor QTLs, making it difficult to determine their exact genetic nature and increasing the possibility that coupling will introduce unwanted alleles into the harvest when QTLs are introduced. For this reason, it is considered useful to perform fine mapping once the approximate positions of QTL have been found. A graphical overview of the flow from QTL analysis to MAS is shown in Figure 2. Plant breeding has been practiced since man began growing crops. Over the past 100 years, the intensity of plant breeding has increased and is now recognized as a complex integration of science (or science) and practicality. Recently, the growing need to feed the world`s population, as well as the ever-increasing demand for a balanced and healthy diet, has led to continued pressure on the production of new and improved plant varieties. The strategies used to produce them are increasingly based on our knowledge of relevant science, especially genetics, but require a multidisciplinary understanding that optimizes the chosen approaches. Im frühen 20.
In the nineteenth century, plant breeders realized that Mendel`s findings about the non-random nature of heredity could be applied to seedling populations produced by deliberate pollination to predict the abundance of different species. Wheat hybrids were bred to increase Italy`s agricultural production during the so-called “grain battle” (1925-1940). Heterosis was explained by George Harrison Shull. It describes the tendency of the offspring of a particular cross to surpass both parents. The demonstration of the usefulness of heterosis for plant breeding has led to the development of inbred lines that have a heterotic yield advantage when crossed. Corn was the first variety in which heterosis was widely used to produce hybrids. The debate over GM foods in the 1990s reached its peak in 1999 in terms of media coverage and risk perception and continues to this day – for example: “Germany threw its weight behind a growing European mutiny on GM crops by banning the cultivation of a widespread pest-resistant maize variety.  The debate focuses on the environmental impact of GM crops, the safety of GM foods and approaches to safety assessment such as substantial equivalence.