New variety cannot be superior to recurrent parent except for the character transferred 2. The usefulness of the paper is obvious: it allows other researchers in the field of education see the benefits of using such a research method. ..... 29 Table 3. IBC breeding ha… HOR204: Backcross Method – Definition Backcrossing - an overview | ScienceDirect Topics 8 Discuss the method of breeding composites. Explain the advantages and disadvantages of using selectable markers, ELISA, and PCR in screening for transgenic plants. Hybridization has to be done for each General Considerations. Predict the amount of time it would take for a specific back-crossing program to … Advanced Backcross Breeding. Lower “vigor” Birth defects. In a backcross system, all male calves produced from the first cross are sold for slaughter. 2. Answer (1 of 4): Back crossing 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. Briefly describe the steps involved for backcross breeding for a dominant gene to be transferred from the donor parent to the recurrent parent. Disadvantages of Backcross Method. Genetic Basis for the Backcross Method. Inbreeding and outbreeding are two methods of breeding, classified based on the relativity of the animals used in the breed. 3. Varieties with Individual Major Gene: In this method an individual major gene is referred for the prevalent race of pest info well adapted cultivar through backcrossing. Homozygous recombinant line can be developed in one generation instead of after numerous backcross generations. Topic 25. In such a cross 100% plants will be red flowered. Female F1 crossbred progeny are mated to males of one of the parental breeds and all progeny are sold for slaughter. But in Texas, U.S.A. the plastic bag emasculation. First cross females are joined with bulls of a third unrelated breed, instead of with one of the parent breeds as in the backcross. So, let’s look at the disadvantages [i] of line breeding and inbreeding: Lower fertility. The third level of MAB involves selecting backcross progeny (that have already been selected for the target trait) with ‘background’ markers. Improvement of More Than One Character. Plant Breeding involves different types or methods that are as follows: 1. It requires lot of time and money. Crop Improvement Method # 1. Multiple QTL methods Why consider multiple QTLs at once? Methods of Plant Breeding. 3. Backcross Method 39 Main features of backcross method 41 Requirements for backcross programme 41 Advantages of backcross method 41 … Use: best when inbred lines are available TYPE OF MAPPING POPULATIONS 8. • If the recurrent parent is an elite genotype, at the end of the backcrossing programme, an elite genotype is recovered. Backcross Method Backcross Method • Number of back-cross generation depends on the relationship between donor parent and recipient parent: • Closely related: less back-cross generation • Distant relation (if donor parent is wild species)-need more back-cross generation to eliminate the undesirable traits from the wild species. Procedure: The general procedure of … which is the backcross (Fig. Varieties with Individual Major Gene: In this method an individual major gene is referred for the prevalent race of pest info well adapted cultivar through backcrossing. The disadvantages of hybrids are that they add an extra step to the breeding process, and increase the cost of seeds since they are produced by hand pollination rather than by bee pollination. 3. The present study focuses on estimating the variation present in backcross inbred lines derived from O. sativa cv. 3 Pedigree selection. Topic 21. Backcross method is mostly followed to improve specific traits in otherwise improved cultivated variety defective for one or few traits such as disease resistance, quality traits, etc. Disadvantages of Plant Introduction. The inbred backcross (IBC) population was proposed by Wehrhahn and Allard (1965) as a way of identifying genes or quantitative trait loci (QTL) that contribute to a quantitatively inherited trait. Lesson home. Advantages and Disadvantages of Experimental Research: Quick Reference List. 5 Single-seed descent. Methods for Mapping QTls Analysis of Variance The simplest method for QTL mapping is analysis of variance (ANOVA, sometimes called "marker regression") at the marker loci4• At each typed marker, one splits the backcross progeny into two groups, according to their genotypes at the marker, and com­ Exploitation of Vertical Resistance 1. Topic 24. 1 FGD: Topics and evaluation methods. But, new genetic variability is not created; only the present one is used just to improve base population performance. This lesson discusses the final stage of developing genetically engineered crops. Experimental and quasi-experimental research can be summarized in terms of their advantages and disadvantages. Topic 20. The trait should be However, the application of molecular markers is helping to change the application of backcrossing to improving quantitative traits. Academia.edu is a platform for academics to share research papers. For example, ELISA detects the presence of a gene product (protein) and thus requires an expressing gene. The variety which receives gene is ‘recipient parent’ and variety which is the source of gene is called as ‘donor parent’ Recipient parent is used repeatedly hence also named as ‘recurrent parent’. The backcross method involves the crossing of hybrid (F 1 or its progenies) of two parents to either parent, with an aim to improve an elite line by adding one or few genes from the donor parent. By the methods of haploid production, time can be redued for a variety development, e.g. methods that can incorporate resistance in crop in plants – backcross breeding, pedigree breeding, genetic basis of backcross breeding, advantages/disadvantages of both. Topic 27. Results show that there is no agreement yet on the advantages and disadvantages of this method. Sometime undesirable gene linked with desirable also may be transferred. Mass selection increases frequencies of desirable genes. Mass Selection: Mass selection is a simplest , common and oldest method of crop improvement, in which large number of plants of similar phenotype are selected and their seeds are harvested and mixed together to constitute the new variety. 2. Plant Introduction 2. Handling of segregating generations– bulk method procedure merits, demerits and achievements of bulk method– comparison between pedigree and bulk method – single seed descent method 15. Artificial production of doubled haploids is important in plant breeding.. Haploid cells are produced from pollen or egg cells or from other cells of the gametophyte, then by induced or spontaneous chromosome doubling, a doubled haploid cell is produced, which can be grown into a doubled … Backcross method is named as “Backcross breeding”. Quantitative trait locus (QTL) analysis is a statistical method that links two types of information— phenotypic data (trait measurements) and genotypic data (usually molecular markers)—in an attempt to explain the genetic basis of variation in complex traits (Falconer & Mackay, 1996; 1. It is a conservative breeding method, 2. a yield ceiling is imposed which equals that of the recurrent parent, 3. it may be outdated as a useful cultivar, and 4. It is not effective for use as the only breeding method. 1. most programs use backcross breeding only on a limited basis, 2. Varieties with Individual Major Gene: In this method an individual major gene is referred for the prevalent race of pest info well adapted cultivar through backcrossing. DNA markers, including RFLP and RAPD analyses, are reliable methods that are widely used. Disadvantages of Backcross Method 1. Mahfuz Ur Rahman Email: 12109085@iubat.edu fGenetics Genetics can be defined as the study of heredity, the process in which a parent passes certain genes onto their offspring. Introduction of insects, pests to the new area, not present earlier. This is a simple, convenient, less expensive and time saving method. The research limitation is that there is almost no Romanian literature on focus group as a method. Tissue Culture 6. However, transfer of polygenic characters is somewhat difficult due to low heritability of such characters and more influence of environment in the expression of polygenic characters. The backcross method is also being used for producing disease-resistant inbred lines to be used as parents in hybrid breeding programs for various crops. Marker-assisted selection is beginning to be used in breeding programs. Exploitation of Vertical Resistance 1. A doubled haploid (DH) is a genotype formed when haploid cells undergo chromosome doubling. Disadvantages: Difficult or impossible in species that are highly heterozygous and outcrossing. •Investigate interactions between QTLs (epistasis). Disadvantages of Backcross It is not necessary to test the variety developed by this method because the performance of recurrent parent is already known. 1. Plant Introduction: Plant introduction usually means the introduction of the plants from places outside the county, may be … (Backcross is a test cross also) (b) When pure dominant (CC) is crossed with a pure recessive (cc). Method 2. Disadvantages Backcrossing is not effective for transferring quantitative traits. Generally, 5-6 backcrosses are sufficient to retain the genotype of recurrent […] Merits and Demerits of Single Seed Descent Method: 1. by this method is not as wide as the pedigree method. (A Vintage Dog Books Breed Classic)An Evaluation of the Inbred-backcross Method for Estimation of Gene Number and for Practical Breeding in TomatoJournal of the Royal Agricultural Society of EnglandPlant BreedingPrinciples of Molecular MedicineGenetic Dissection of Complex TraitsAn Introduction to Plant Method of Plant Breeding in Self Pollinated Plants – Mass Selection. Explain the advantages and disadvantages of using selectable markers, ELISA, and PCR in screening for transgenic plants during the backcrossing process. Time consuming as it requires twelve years to raise an improved variety. PCR amplicons are resolved using standard agarose gel electrophoresis. The statistical methods used, and the statistical issues that arise, are largelythe same for the different types of crosses; however, the backcross has the ad-vantage of simplicity: at each locus in the genome, the back-cross progeny have one of only two possible genotypes (ge-netic composition). And to: 6 Describe the technique/method of backcrossing. Handling of segregating generations– backcross method of reeding – its requirements and b Backcross-Dominant gene transfer. Fewer offspring. The presence of undesirable linkages may prevent the cultivar being improved from This lesson discusses the final stage of developing genetically engineered crops. Predict the amount of time it would take for a specific backcrossing program to be completed. Genetic Engineering. Applications of Back Cross Method. Advantages and disadvantages of the backcross breeding method. Heredity describes how some traits are passed from parents to their children. Themain difference between inbreeding and outbreeding is that inbreeding is a breeding method that involves more closely-related individuals whereas outbreeding is a breeding method that involves unrelated animals. QTLs are mapped by identifying which molecular markers (such as SNPs or AFLPs) correlate with an observed trait.This is often an early step in identifying and sequencing the actual genes that cause the trait variation. All progeny of F1 dams are sold for slaughter (55). Several different populations may be utilized for mapping within a given plant species, with each population type possessing advantages and disadvantages 5 . Backcross Method – Definition. Demerits of the method can be listed as follows. Selection methods. The two basic methods to detect the presence of a gene/transgene are ELISA and PCR amplification. sizes compared to pedigree method There is no need of keeping much record in this method. 3. or backcross method. A quantitative trait locus (QTL) is a locus (section of DNA) that correlates with variation of a quantitative trait in the phenotype of a population of organisms. • Requires smaller pop. Quiz. Smaller size. method – merits, demerits and achievements 14. Several different populations may be utilized for mapping within a given plant species, with each population type possessing advantages and disadvantages 5 . Topic 22. Mutant Breeding 4. The new variety is superior over the already available variety only in the transferred character. Yield lag, yield drag, and gene stacking are also discussed. In this method, the parent used for backcrossing has a large number of desirable attributes but lacks a few characteristics.50 Marker-assisted backcrossing is … The advantages of the backcross method are its rapidity, the small number of plants required, and the predictability of the outcome. 7 Discuss the method of multiline breeding. 4. •Separate linked QTLs. 10 to 6 years or less. Yield lag, yield drag, and gene stacking are also discussed. Table 2.1 Advantages and disadvantages of sorghum different crossing technics..... 19 Table 2. It involves lot of crossing work. 4 QTL mapping Data Phenotypes: y i = trait value for mouse i Genotype: x ij = 1/0 (i.e., A/H) of mousei at marker j (backcross); need two dummy variables for intercross Genetic map: Locations of markers Goals • Identify the (or at least one) genomic region, called Organic farming starts with breeding. Overview and Objectives - The Backcrossing Process This lesson discusses the final stage of developing genetically engineered crops. Generally, 5-6 backcrosses are sufficient to retain the genotype of … Pure line selection method is most applicable in hybridization programme, i.e., selection from segregat­ing generations of crosses. The backcross method was first proposed as an appropriate breeding method for cereal crops in 1922 by Harlan and pope . An Evaluation of the Inbred-backcross Method for Estimation of Gene Number and for Practical Breeding in … Along similar principles as with backcross, all first cross male progeny are sold. In vegetatively propagated crops like sugarcane and potato this method is rarely used and that too with some modifications. 1. Application: The backcross method is generally used to improve specific character of a well-adapted variety for which it is deficient such as resistance to a specific disease. Hybrid Breeding. Undesirable genes may also be transferred to the new variety. The pure lines in such cases may be selected using pedigree, bulk or backcross methods. Backcross method is generally used for transfer of monogenic or oilgogenic characters. Topic 23. In most cases, Plants that are cross breed tend to be more vigorous and faster growing than the parent plants. Resistant plants are selected from segregating population and backcrossed to the recurrent parent. Polyploidy 5. Breeding refers to the mating and production of offspring by animals. It is not affected by environmental conditions. Genetic consequences. to identify large numbers of markers dispersed throughout the assisted selection (MAS) methods in varies of crops David 2007. genetic material of any species of interest and use the markers to detect associations with traits of interest John & Andrea [2], thus allowing marker assisted selection (MAS) finally to become a reality. The advantages and disadvantages of the RGA method based on findings from multiple crops were reviewed by Jensen (1988). The major disadvantage of AFLP markers is that these are dominant markers. The backcross method takes four to five years for transfer of male sterility from one genotype to another. Resistant plants are selected from segregating population and backcrossed to the recurrent parent. Next Page. 662 686-5220 (office) 662 686-5218 (fax) This method provides the advantage of a straightforward calculation along with an intuitive parameter selection. Title: Development of trispecies backcross populations using a 2(ADD) hexaploid bridging line to introgress genes from A-genome diploids into upland cotton Discipline: Plant Breeding and Genetics Authors: Erik J. Sacks (corresponding author) USDA-ARS 141 Experiment Station Rd Stoneville, MS 38776 esacks@ars.usda.gov. The need for backcrossing, and the steps of this breeding method are described. The variety which receives gene is ‘ recipient parent ’ and variety which is the source of gene is called as ‘ … Selection of parents. It is a rapid method of developing male serile line. The majority of the genome of each line is from the recurrent parent, with a small portion from the donor parent. In this cross 50% plants will be red and 50% will be white B. Therefor, We did our research and found out what are the advantages and disadvantages of cross breeding ( Hybridization ) in plants and it will affect the way we look at gardening in the future. Acclimatization 3. Introduction of noxious weeds to the new area not present earlier. Backcross -Recessive gene transfer. 1). Organic plant breeding is defined by the IFOAM standard and bears a high potential to provide farms with varieties perfectly adapted to organic farming. 4 Bulk population. Three breed cross requires the input of three separate breeds (55). Sometimes undesirable genes are closely linked with desirable one and get transferred to the new variety. There can be two possibilities of such a cross: (a) When impure dominant (Cc) is crossed with the pure recessive. 1. ..... 23 Table 3. In India, hand emasculation. - Methods of improvements for cultivars of kinds _ Breeding methods for sexually propagated crops _ Breeding methods for asexually propagated crops LECTURE 4 - Selection methods in Plant Breeding based on mode of reproduction - Methods for breeding self pollinated crops - Mass selection: Applications, Advantages & Disadvantages The methods are: 1. The backcross method involves the crossing of hybrid (F 1 or its progenies) of two parents to either parent, with an aim to improve an elite line by adding one or few genes from the donor parent.