What is the method of back cross?
Introduction to Backcross Breeding. A breeding method used to move one or a only a few desirable genes from an agronomically poor crop line to an elite line. This is done by crossing a donor parent to an elite line, and crossing offspring with the ‘desired gene(s)’ back to the elite parent.
What is Back cross in plant breeding?
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. The backcross is useful in genetics studies for isolating (separating out) certain characteristics in a related group of animals or plants.
Why backcross method is used?
Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, to achieve offspring with a genetic identity closer to that of the parent. It is used in horticulture, animal breeding, and production of gene knockout organisms.
What are requirements of back cross breeding?
Requirement of back cross breeding
- Suitable recurrent parent must be available which lacks in one or two characteristics.
- A suitable donor parent must be available, the character must be highly intense.
- Character to be transferred must have high heritability controlled by one or two genes.
What is the difference between test cross and back cross?
Zygosity refers to the proportion of individuals that can be either homozygous or heterozygous. A heterozygous genotype has a dominant and a recessive allele….Differentiate between back cross and test cross.
| Test cross | Back cross |
|---|---|
| All test crosses are backcrosses. | A backcross can be said as a test cross if the parent is recessive. |
Who proposed back cross method?
Borlaug
In 1954, Borlaug suggested that several purelines with different resistance genes should be developed through back cross programmes using one recurrent parent. This is done by transferring disease resistance genes from several donor parents carrying different resistant genes to a single recurrent parent.
What is the difference between test cross and backcross?
Does backcross breeding widely used?
Backcrossing is the plant breeding method most widely used to incorporate one or a few genes into an elite or adapted variety. In this method, the parent used for backcrossing has a large number of desirable attributes but lacks a few characteristics.
How backcross breeding method is different from pedigree method?
Hybridization with the recurrent parent is done in every back-cross generation. The progeny of back-cross generations are smaller than pedigree method. 8. This method is different for transferring dominant and recessive gene controlled character.
Why test cross is a type of back cross?
Test cross is a kind of back cross. All the test crosses are back crosses because in the test cross F1 generation having dominant phenotype is crossed to the parent plant having homozygous recessive genotype or recessive phenotype.
Why test cross is called back cross?
Why test cross are backcross but backcross is not test cross?
Thus, in the back cross, if F1 generation is crossed with a recessive parent it will be a test cross, but if F1 generation is crossed with a dominant parent it will not be a test cross. Therefore, the test cross is a back cross but the back cross is not necessarily a test cross.
What are the uses of backcrossing in agriculture?
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.
What is the backcross method used for?
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.
What is the difference between pedigree method and backcross method of resistance?
The pedigree method is used when the resistance is governed by polygene and the resistant variety is an adapted one which also contributes some desirable agronomic traits. The backcross method is used when resistance to governed by oligogenes. Induced mutations are also use for disease resistance.
How to identify resistant homozygous recessive plants after each backcross?
In such case, the progeny of each backcross will segregate into two genotypes (RR and Rr) which cannot be identified. Therefore, it is necessary to self the population after each backcross to obtain resistant homozygous recessive plants (rr). The resistant plants are identified by growing the F 2 material in wilt sick plot.