Markerassisted introgression in backcross breeding programs peter m. For the successful development of a new variety through the backcross method, the following requirements must be fulfilled. In this cross 50% plants will be red and 50% will be white b. Weaber department of animal science and industry kansas state university introduction the dramatic changes and volatility cowcalf production system input costs and calf values have many producers wondering about the value of heterosis in todays beef. Backcrossing is a wellknown and long established breeding scheme where a characteristic is introgressed from a donor parent into the genomic background of a recurrent parent. Its efficiency depends on the experimental design, most notably on the marker density and position, population size, and selection strategy. After initial eight generations of backcross breeding f1 to f8 or during directional selection stage f9 to f32, the selection pressure was applied at all the four stages of development viz. Sep 26, 2010 test cross and a back cross are the same use a double recessive in the cross. You may get dogs with the right behaviors, and the wrong look, the genes may nick wrong and youll get a whole litter that is useless, you may not get what you want out of the backcross and have to try another one. Microsatelliteassisted backcross selection in maize scielo. Backcrossing backcross breeding is a wellknown procedure for the introgression of a target gene from a donor line into the genomic background of a recipient line. Pdf modified backcross breeding method for rapid conversion of. Markerassisted backcross breeding to combine multiple. If the trait of interest is produced by a dominant gene, this process involves four rounds of backcrossing within seven seasons.
Rather, it is the systematic use of breed resources to produce offspring of a specific type. Backcross breeding mab is a wellknown procedure for the introgression of a target gene from a donor line into the genomic background of a recipient line. The below mentioned article will highlight the two types of experiment performed by mendel. This is the planting program that is the most rewarding and the one we need the most. Backcross breeding is a traditional plant breeding method used by modern plant breeding programs to incorporate transgenes into elite lines. First, determine your production conditions including climatic, forage and marketing and the levels of animal performance that fit those conditions. Analytical and decision support tools for genomicsassisted. Combining ability analysis in complete diallel cross of. Continue to develop and release high yielding, spring, tworow feed barley varieties with improved disease resistance, high protein and test weight. Ppt plant breeding methods powerpoint presentation free. The purpose of this discussion paper is to facilitate a broad discussion with organic farmers and other stakeholders, such as breeding companies, interest groups and policymakers. Reciprocal cross is different a pair of crosses in which the male or. Marker assisted backcross breeding approach to improve. How introduce traits in maize by back cross breeding youtube.
Pdf backcrossing is a wellknown and long established breeding scheme. Crossbreeding is the recommended breeding strategy for commercial meat sheep and meat goat production. Merging backcross breeding and transgenic blight resistance to. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Yorkshires have acceptable rates of gain in muscle. Markerassisted backcross breeding to combine multiple rust resistance in wheat article in plant breeding 42. F1 hybrids and f2 backcross hybrids were raised and used as parental broodstock in 2 cycles of backcrossing. The outcrossing breeder intends to remove the traits by using new blood. With dominant traits, one can still see the expression of the traits and can remove those traits whether one outcrosses, line breeds or inbreeds.
Optimized breeding strategies for multiple trait integration. Users can directly access and browse specific projects, create new projects, administer programme members, breeding locations. Backcross method is the one whose main objective is to incorporate desired gene, either dominant or recessive, to the highly productive, commercially successful variety which lacks that specific gene. You may get dogs with the right behaviors, and the wrong look, the. Background genotypes were simulated assuming that a genetic model of many genes of small effects in coupling phase explains the observed breed difference and variance in backcross populations.
Sponenberg is a dvm, phd, professor, pathology and genetics at virginia maryland regional college of veterinary medicine, virginia tech, blacksburg, va. The american chestnut foundations breeding program is approaching major milestones. Markerassisted introgression in backcross breeding programs. Site selection growing trees in oldham county, shelby county and jefferson county.
Winner of the standing ovation award for best powerpoint templates from presentations magazine. Recurrent parentan elite line that can be made better by adding the gene of interest. Chestnut was present in pockets in these counties, as shown by some surviving old log cabins with chestnut in the logs. Merging backcross breeding and transgenic blight resistance to accelerate restoration of the american chestnut the american chestnut foundations breeding and selection plan 2015 2025 jared westbrook director of science, tacf national office, asheville, nc revised february 12th 2018. This is the practice of introducing unrelated genetic material into a breeding line. We use cookies to offer you a better experience, personalize content, tailor advertising, provide social media features, and better understand the use of our services. Unesco eolss sample chapters soils, plant growth and crop production vol. Backcross method for dominant and recessive gene transfer. Ppt plant breeding methods powerpoint presentation. At the american chestnut foundation tacf, however, the primary approach is to continually cross back to the american parent, not to the chinese and japanese species. Assisted backcrossing for simultaneous introgression of. Pdf selection in backcross programmes researchgate.
A is a merged image, b is a telomere repeat which has homology to bspecific repeat. Sep 14, 2016 backcrossing backcross breeding is a wellknown procedure for the introgression of a target gene from a donor line into the genomic background of a recipient line. A free powerpoint ppt presentation displayed as a flash slide show on id. This method, called backcross breeding, is the standard method for transferring a single trait into an otherwise acceptable plant. Backcross breeding method 410 hort 407 2 backcross breeding at the end, all genes will be homozygous except the genes transferred from the donor parent one or few generation of selfing will result in a variety homozygous at all loci, including newly transferred genes the new variety would have all the adaptability of the recurrent parent in addition to the good characteristics of the.
Outcrossing is now the norm of most purposeful animal breeding, contrary to what is commonly believed. Markerassisted backcrossing is routinely applied in breeding programs for. The objective is to reduce the donor genome content dgc of the progenies by repeated backcrosses. Moving south towards the knobs, there are rare old chestnut ghosts still standing.
An example is the crossbreeding of yorkshire and duroc breeds of pigs. Pdf marker assisted backcross breeding approach to improve. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. The american chestnut foundations scientific approach. First, determine your production conditions including climatic, for. Gama eeg, vianna rt and moro jr 1981 general and specific combining. Although the transgene is put into a soybean plant in the plant transformation process. Normally, breeds are chosen that have complementary traits that will enhance the offsprings economic value. Haley and robin thompson roslin institute edinburgh, roslin, midlothian eh25 sps, scotland manuscript received december 12, 1995 accepted for publication august 28, 1996 abstract. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Goals objectives barley breeding is an ongoing research project that addresses the changing needs of the washington barley industry through the continued release of varieties with improved agronomic traits and enduse quality. Markerassisted backcrossing is routinely applied in breeding programs for gene introgression. Although the transgene is put into a soybean plant in the plant transformation process, the variety used for transformation is not the latest and greatest.
Backcrossing flowchart genetically engineered murine. Explain the advantages and disadvantages of using selectable markers, elisa, and pcr in screening for transgenic plants during the backcrossing process. Share your knowledge share your word file share your pdf file. It is a commitment of an acre of welldrained soil, and of 8 to 10. The backcross breeding orchards, purpose and implementation. The symbols and definitions for mouse generation numbers used by the jackson laboratory are. To successfully implement genomicsassisted breeding gab in crop. The sequence alignment files from all of the bils were merged together and. At this point of the backcrossing, the offspring will be the progenitors of the desired congenic strain. Backcross breeding method 410 hort 407 4 backcross breeding at the end, all genes will be homozygous except the genes transferred from the donor parent one or few generation of selfing will result in a variety homozygous at all loci, including newly transferred genes the new variety would have all the adaptability of the recurrent parent in addition to the good characteristics of the. After that point the plant breeder can work with the genetically engineered line in the same manner they work with other parents in their breeding program. List reasons why backcross breeding is necessary in developing genetically engineered lines.
If an individual is homozygous for the horned condition, it is horned, regardless of any presence or absence of the scur gene. Oct 11, 2012 the back cross method is used to introduce he desirable traits in the elite lines from the donor lines. If the trait of interest is produced by a dominant gene, this process involves four rounds of. In vegetatively propagated crops like sugarcane and potato this method is rarely used and that too with some modifications. If the trait of interest is produced by a dominant gene, this process involves four rounds of backcrossing. Marker assisted selection or marker aided selection mas is an indirect selection process where a trait of interest is selected based on a marker morphological, biochemical or dnarna variation linked to a trait of interest e. The backcross method of breeding is commonly used in self and cross pollinated species. Backcross breeding enables breeders to transfer a desired trait such as a transgene from one variety donor parent, dp into the favored genetic background of another recurrent parent, rp. It increases genetic diversity, thus reducing the probability of an individual being subject to disease or genetic abnormalities outcrossing is now the norm of most purposeful animal breeding. Dec 22, 2015 backcross method for dominant and recessive gene transfer. The back cross method is used to introduce he desirable traits in the elite lines from the donor lines. Backcross, the mating of a hybrid organism offspring of genetically unlike parents with one of its parents or with an organism genetically similar to the parent.
Pdf marker assisted backcross breeding approach to. Investigations view this article with lens email print alerts view pdf. A suitable recurrent parent must be available, which lacks one or two characteristics. Ppt backcross breeding powerpoint presentation free to. Alabama scientists and activists helping to rehabilitate. Backcrossing flowchart genetically engineered murine model. Hammack a logical genetic strategy for a beef cow herd should include four steps. Breeding strategies article from the goat farmer mayjune 2000 by d. Mouse strain generation numbers provide additional information on the genetic background and breeding history of mouse strains that cannot be captured in the mouse strain names.
Only plants from rr bc2 plants are crossed to rp single recessive allele progeny test in same season each bc4f1 plant is progeny tested. The efficiency of markerassisted introgression in backcross populations derived from inbred lines was investigated by simulation. Here, we report on a new advanced backcross qtl mapping resource for tomato, derived. You will need to backcross, and you will need to keep more than one or two puppies to choose from for that backcross. Main screen that gives an overview of all projects and their contents. In breeding programs with three backcross generations, the least mdp. Backcross article about backcross by the free dictionary. May 27, 2014 marker assisted backcrossing breeding has become one of the essential tools in transferring novel genes to adapted varieties and was employed to pyramid three blast resistance genes pi1, pi2 and pi33 to a popular susceptible rice variety adt43. Selection theory for markerassisted backcrossing ncbi. Selection theory for markerassisted backcrossing genetics. The theory and application of the backcross technique in cotton. Improvement of early maturity in rice variety by marker assisted backcross. A new advanced backcross tomato population enables high.
Crossbreeding involves the mating of animals from two breeds. Markerassisted backcrossing is routinely applied for gene introgression in plant and animal breeding. Backcross definition of backcross by the free dictionary. The two types of experiment performed by mendel are. Kidwell encyclopedia of life support systems eolss dianthus herbatus and thus was more botanical in nature rather than aimed at the improvement of a crop population. Lua bc2 x akc dal backcross 3 bc3 4 3 1 3 26 16 30 3.
Linkage drag in backcross breeding in barley article pdf available in journal of heredity 803. The book markerassisted plant breeding is designed to provide uptodate information on. The backcross orchard is a basic unit of the tacf breeding program. Plant breeding and genetics encyclopedia of life support. Texas adapted genetic strategies for beef cattle iv. Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, in order to achieve offspring with a genetic identity which is closer to that of the parent. Analysis of recurrent parent genome recovery in markerassisted. It is used in horticulture, animal breeding and in production of gene knockout organisms. It takes the breeder at least two or three years to derive a backcross line that is the genetic equivalent of the elite line plus the event. How introduce traits in maize by back cross breeding genomics lab.
The backcross is useful in genetics studies for isolating separating out certain characteristics in a related group of animals or plants. From a breeding standpoint, multiple trait integration mti is a fourstep. Selection of the most blightresistant backcross trees in seed orchards. Cross breeding is the process of breeding with the intention to create offspring that share the traits of both parent lineages or to produce an animal with hybrid vigour the improved or increased function of any biological quality in a hybrid offspring.
As a breeding practice, crossbreeding does not denote the indiscriminate mixing of breeds. When f1 individuals are crossed with one of the two parents either ccred flowered or ccwhite flowered. The symbols and definitions for mouse generation numbers used by the jackson laboratory are listed below. Backcross is a test cross also b when pure dominant cc is crossed with a pure recessive cc. In order to get the transgene in the very best varieties that farmers want to grow, breeders must cross the. Marker assisted backcrossing breeding has become one of the essential tools in transferring novel genes to adapted varieties and was employed to pyramid three blast resistance genes pi1, pi2 and pi33 to a popular susceptible rice variety adt43. Gene pyramiding process was facilitated by marker aided selection for both foreground as well as background genotype. Outcrossing or outbreeding is the technique of crossing between different breeds with no common ancestors. Agriculture merged to become the national research institute for agriculture. If you continue browsing the site, you agree to the use of cookies on this website. Backcross breeding and directional selection of two.
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