Speed breeding for multiple quantitative traits in durum wheat

Area of Science:

• Plant breeding and genetics
• Agricultural science
• Crop improvement

Background:

• Traditional plant breeding is a lengthy, multi-generational process.
• Speed breeding accelerates generation cycling in wheat, achieving six generations annually.
• This study pioneers speed breeding for multi-trait selection in durum wheat.

Purpose of the Study:

• To adapt and deploy speed breeding for simultaneous selection of multiple traits in durum wheat.
• To evaluate a novel multi-trait phenotyping approach for above and below-ground characteristics.
• To assess the efficiency of a weighted selection index for durum wheat improvement.

Main Methods:

• Phenotyped 1000 F2 individuals for seminal root angle (RA), root number (RN), crown rot (CR) tolerance, leaf rust (LR) resistance, and plant height (PH).
• Developed and applied a weighted selection index (SI) for simultaneous trait selection.
• Evaluated F3 progeny from selected and unselected F2 individuals to determine trait gain.

Main Results:

• Observed transgressive segregation for all assayed traits in the F2 population.
• The SI successfully shifted population means for CR tolerance, LR resistance, RA, and RN.
• No significant shift in plant height (PH) was observed, but other key traits showed improvement.

Conclusions:

• The multi-trait phenotyping method is effective for rapid selection in early filial generations and out-of-season characterization.
• Integrating speed breeding with multi-trait selection efficiently enriches breeding populations with desirable alleles.
• This approach significantly reduces the time and resources needed to develop improved durum wheat cultivars.