Investigating the efficiency of the single backcrossing breeding strategy through computer simulation

Area of Science:

• Plant breeding
• Genetics
• Agricultural science

Background:

• Introgression of rust resistance genes is crucial for wheat improvement.
• CIMMYT has successfully used single backcrossing with bulk breeding for gene transfer.
• Evaluating breeding strategy efficiency requires comparative analysis.

Purpose of the Study:

• To compare the efficiency of single backcrossing breeding strategy (SBBS) against other methods.
• To assess SBBS's effectiveness in gene introgression and adaptation maintenance.
• To identify optimal conditions for implementing SBBS in wheat breeding.

Main Methods:

• Computer simulation of various crossing and selection strategies.
• Modeling gene introgression from donor to elite adapted wheat cultivars.
• Analysis of adaptation and gene transfer under different scenarios.

Main Results:

• SBBS demonstrates advantages in retaining/improving recurrent parent adaptation.
• SBBS efficiently transfers desired donor genes across diverse scenarios.
• Two backcrosses are beneficial when donor adaptation is poor; three offer minimal additional advantage.

Conclusions:

• SBBS is recommended when multiple genes control traits, donors offer adaptive benefits, and phenotypic selection is used.
• SBBS is widely applicable in modern breeding programs under these conditions.
• Repeated backcrossing may be useful only if genes are identifiable via molecular markers and donors have very poor adaptation.