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Backcross-Advantages-Applications

Backcross breeding method has certain advantages and applications. Some of them are listed below.

Merits of back cross method are given here.

Gives predicted results. Extensive tests are not necessary as recurrent parent is usually a well established variety
We can obtain same results again and again
While eliminating defects of well established variety there is no much change in its adaptability, performance and genotypic background
Only method for interspecific gene transfer.
Independent of environment
This method offers considerable control over the genetic variation in the segregating population under consideration
Little record keeping
Requires small populations
Backcrossing is applicable for both – dominant gene transfer and recessive gene transfer.

Demerits of back cross method are given here.

Newly developed variety is superior to the recurrent parent only for the character which is transferred, not for others.
Ineffective for traits with low heritability means quantitative traits.
If undesirable genes are closely linked to the desired gene, the undesirable genes are probably transferred along with the desired gene to the new variety.
Little recombination
Its lengthy process, by the time we transfer a gene to the variety, that variety may have been replaced by other superior varieties.

Applications of back cross method are given here.

Intervarietal transfer of qualitative characters and quantitative characters with high heritability.
Interspecific transfer of traits with high heritability.
To improve well established variety with respect to one or few characters.
Isogenic lines production
Cytoplasm transfer esp. with cytoplasmic male sterility (CMS) involved, used to transfer male sterility into purelines, which is a prerequisite for many hybrid production breeding programs.
Production of transgressive segregants is possible by modification of the method.