An alternative to recurrent backcrossing known as congruity backcrossing that uses multiple backcrosses alternating between the tepary and common bean parents to overcome the interspecific hybridization barrier of hybrid sterility, genotype incompatibility, and embryo abortion found in simple interspecific crosses, was proposed by Haghighi and Ascher (1988).
The number of tepary bean AFLP bands introgressed into the congruity backcross lines was compared with the number of tepary bean AFLP bands found in a group of cultivars and lines developed from recurrent backcrossing.
The interspecific genotypes included 34 lines from congruity backcrosses between ICA Pijao (common bean) and G40001 (tepary bean), four lines from single backcrosses with the same parents and 14 interspecific cultivars and advanced lines from recurrent backcrossing involving other parents.
A third set of genotypes included interspecific lines and cultivars derived from standard recurrent backcrossing and selection.
The first group contained all cultivars or advanced lines without tepary bean parentage (ICA Pijao and BAT41) and all the interspecific hybrids from a single or multiple recurrent backcrossing.
To reach this goal, hexaploids can be used either directly through recurrent backcrossing
to the tetraploid parent (Brown and Menzel, 1950) or indirectly through the development of trispecific allotetraploid hybrids with A- or D-genome diploid bridging species (Deodikar, 1949).
The simultaneous introgression of two genes from different sources into the genetic background of one recipient genotype by recurrent backcrossing
is a common task, for example, in the development of inbred lines for hybrid varieties or line cultivars in autogamous species.
Marker-assisted foreground selection was proposed by Tanksley (1983) and investigated in the context of introgression of resistance genes by Melchinger (1990), who presented an a priori approach for calculating the minimum number of individuals and family size required in recurrent backcrossing
The Xa21 gene was introgressed into Minghui 63 following a recurrent backcrossing
procedure, combined with tandem selection using molecular markers.
RECURRENT BACKCROSSING is a breeding method commonly employed to transfer alleles at one or more loci from a donor to a recurrent parent (Allard, 1960).
Molecular markers are used in recurrent backcrossing for two purposes: (i) as a diagnostic tool for tracing the presence of a target allele, for which direct selection is difficult or impossible (e.
Complete expression of tolerance from Atlas 66 was not achieved via recurrent backcrossing