Strategy for exploiting exotic germplasm using genetic, morphological, and environmental diversity: the Aegilops...

Area of Science:

• Plant genetics
• Crop science
• Evolutionary biology

Background:

• Hexaploid bread wheat (Triticum aestivum) experienced genetic diversity loss in its D-genome from its ancestor, Aegilops tauschii.
• Limited information on Aegilops tauschii accessions hinders the selection process for wheat re-synthesis programs.
• Recreating hybridization offers a path to introduce novel genetic variation into modern wheat.

Purpose of the Study:

• To develop and evaluate methodologies for identifying novel genetic diversity within Aegilops tauschii accessions.
• To compare diversity levels among Aegilops tauschii accessions, modern bread wheat, and synthetic hexaploid wheat lines.
• To inform rational selection strategies for incorporating wild relatives into wheat breeding programs.

Main Methods:

• Bayesian analysis of genotypic data.
• Assessment of subspecies diversity.
• Integration of geographic information, including climate and habitat data at collection points.
• Comparative analysis of diversity across different wheat populations.

Main Results:

• Methodologies combining genotypic, subspecies, and geographic data effectively identified novel diversity in Aegilops tauschii.
• The approach used to select Aegilops tauschii accessions significantly impacted the diversity within the resulting sets.
• Diversity levels varied considerably between Aegilops tauschii accessions, bread wheat varieties, and synthetic hexaploid wheat lines.

Conclusions:

• A multi-criteria strategy is most effective for maximizing sampled variation across diverse parameters.
• Analyzing multiple layers of variation in ex situ collections of Aegilops tauschii enables informed selection for crop breeding.
• This approach facilitates the rational inclusion of wild relatives to enhance modern wheat genetic diversity.