Marker Assisted Selection
- haley norlie
- Mar 8, 2016
- 5 min read
BACKGROUND
Agricultural Biotechnology is defined in the catagories of tools, such as breeding techniques that alter living organisms to make products, improve animals and use then for agricultural uses. Many farmers have had a point in there life where they need sustainable crops to overcome new environments and weather conditions. Since the 1920s biologists and scientists have worked with mutations and trying different methods to the solution of this problem. With that being said Marker assisted selection, one of the many breeding methods discovered, is a "short cut" for plant breeders with this problem. This section below will give you information about marker assisted selection.
Marker assisted selection is where a trait is selectivly chosen but not for the trait itself but for the marker inside of it. Since all traits are controlled by gnes scientist chose particular genes for their liking. This allows scientists to make is easier and faster to select important plant traits we want in our food and animals.. The nucleic acid string or sequence from the DNA forms the markers. Markers are located near the DNA segment of the desired gene. The first production of MAS (marker assisted selection) started back in the mid 1990s. Most scientist have tried over the years to create these plants that pertained the specific trait they wanted in it. Those scientist chose the genotype plants that fit well with the desirable trait they wanted to add to it. "By determining the allele of a DNA marker, plants that possess particular genes or quantitative trait loci (QTLs) may be indenified based on their genotype rather than their phenotype" (International Rice Research Institute, 2006). By using marker assisted selection scientisst are able to determine the genotype of the specific desirable trait they want in the plant and can over the years create a plant with future generations of great traits.
In the picture above the flags represent its self as the markers and the green section highlights the only trait that is desirable and well marked for that manner. Genetic markers are basically the red flags in DNA and represent much more than a tiny section. All the Gentic marker is, is just a fragment of DNA that holds a trait inside.
MAS uses gene mapping to conduct the specific genotypes the DNA has. QTL mapping (Quantitive trait locus) and Gene mapping is the process of locating and identifying genes locus along a chromosome. With these studies, scientist are able to locate specfic phenotypes through a series of maps and basically select it out. Through genetic mapping, scientist can prove whether the trait of interest will be passed down from mother to child. Scientists do this by collecting data such as blood, DNA, or tissue of the plant or animal. This process links the desease or illness to a members of the family who have that certain desease. Using this formula helps scientists pick the best ones out of the group of animals to use in MAS.
MOLECULAR MARKERS
Markers are found in genes that have the specfic traits we want in our animals and food. They can be used to study certain genotypes and phenotypes of an organisum. By usig this tenchique, reseachers and scientists can make judgements on breeding methods used with the certain animal or plant. One of the best molecular markers are ones that inherrit multiple alleles which can all be seen. Markers are abundant throughout the entire genome. "Markers can aid selection for target alleles that are not easily assayed in individual plants, minimize linkage drag around the target gene, and reduce the number of generations required to recover a very high percentage of the recurrent parent genetic background" (Ashwani Kumar). Many markers have been discovered over the years and the number is still continuing to grow. Markers have and carry traits that can be both harmful and harmless. Scientists find these traits and use them to make the desirable animal & plant they want. There are many pros and cons to this specific range of molecular markers.
CASE STUDY: MARKER ASSISTED SELECTION COST -EFFECTIVE?
This case study of MAS is on crops and how they can be more efficient with the desirable traits enlisted in their DNA. Crops are a good example, scientists can make and improve them to supply winters cold frost, and insects potentially killing the crops. With the new improved crops we can create more food for us and all in all better and stronger crops who can face the challenges coming. The main problem for these reseachers and scientist here is whether this plant-breeding method was cost effective. There are many breeding methods in the scientific world to chose from, but would MAS be cost beneficial for them? This case study was conducted in Mexico for the International Maize and Wheat Immprovement Center. Maize is commonly known as corn, but a tad bit larger.
The study was mainly focused on transfering the Maize phenotype protein to the F1 generation and so on. "Maize varieties tend to be low in two essential amino acids, lysine and tryptophan. Over the past 30 years, scientists at CIMMYT have developed high yielding maize lines with enhanced levels ofthese amino acids together with dramatically higher total protein levels. This advance has recently been awarded the World Food Prize for 2000. The demand for transferring the quality protein trait into new elite locally adapted lines o f maize is likely to be very high" (Jonathan Couch, 7). Goals accumulated from this case study was to see if the costing range of MAS was high and demanding. The case study have mainly three objectives:
"1. Generate detailed information about the cost of carrying out conventional breeding operations as well as cost of implementing MAS procedures at CIMMYT's reseach facilities in Mexico.
2. To determine the cost-effectiveness of using MAS for a particular breeding application, namely QPM line conversation and,
3. To provide insights into the likely cost-effectiveness of potential future applications of MAS whose costs and benefits are not known yet" (David Zilberman, 204).
The case study mostly resulting in cost and production of crops based on MAS. Reseachers discovered MAS growth in Maize would work to support the cereal demand in countries. The cost effecting MAS is still being reseached into further studies. MAS was effective and the cost was decent but really should go on into further conclusions.
Book and website Citations:
Zilberman, David NA. "Economic and Social Issues in Agricultural Biotechnology." Google Books. Robert E. Evenson, na. Web. 10 Mar. 2016. https://books.google.com/books?id=11ssEVh-ydoC&pg=PA251&lpg=PA251&dq=Economic+and+Social+Issues+in+Agricultural+Biotechnology&source=bl&ots=Dt22wy0yGS&sig=jGWCJgA6D6V5N-YaKsZsE7eT9BI&hl=en&sa=X&ved=0ahUKEwiDo-XXo77LAhWJKGMKHZ26A8AQ6AEITDAH#v=onepage&q=Economic%20and%20Social%20Issues%20in%20Agricultural%20Biotechnology&f=false
Kumar, Ashwani. "Molecular Markers." Science 2.0. n/a, 1 Nov. 2009. Web. 11 Mar. 2016.
"Molecular Breeding." 5.1 Marker Assisted Breeding. International Rice Research Institute, 2006. Web. 13 Mar. 2016.
Crouch, Jonathan H. Molecular Marker-Assisted Breeding (n.d.): n. pag. Molecular Marker-Assisted Breeding. Web. 14 Mar. 2016.
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