Domestication of perennial flax using an ideotype approach for oilseed, cut flower, and garden performance

Flaxseed (Linum usitatissimum) has recently grown in popularity as a health food due to its high levels of omega-3 fatty acids. Many undomesticated Linum species possess a similar oil profile, in addition to perenniality, and could, therefore, provide similar products in addition to ecosystem services such as soil retention, improvements in water quality, and pollinator services. Many Linum species also possess ornamental qualities, e.g., blue flowers, which could provide added value as a new cut flower crop or garden herbaceous perennial. A perennial flax breeding program will be initiated by screening of Linum accessions for key agronomic and horticultural traits. Herein, we outline an ideotype approach which will enable identification of top herbaceous perennial candidates for domestication based on qualities relevant to oilseed, cut flower, and garden herbaceous perennial crop uses. In this review, we summarize the concept of ideotype breeding as it relates to perennial crop domestication and outline considerations for ideotype design. The tools outlined herein should prove useful to other breeders and especially for undomesticated crops. Whether the ideotype concept is applied as a framework for selection or simply as a means of generating hypotheses, applying this approach can provide structure to breeding programs with complex objectives.