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Home HortScience Selfheal Study: Medicinal Herb’s Genetics Evolving
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AMES, IA—Selfheal, an herb with a long history of use in traditional Chinese and European medicine as a remedy for sore throat, fever, and wounds, is emerging as important medicinal herb in the United States. As new studies reveal the medicinal herb’s anti-inflammatory, antiviral, and antibacterial properties, insiders predict increased commercial demand for the perennial, challenging scientists to find ways to optimize commercial production and genetically improve the species.

Previous studies of selfheal (Prunella vulgaris) have suggested substantial genetic variations among populations, at least in terms of phytochemical properties. In one study, for example, 11 accessions of the species were shown to differ more than 10-fold in their concentration of the bioactive compound rosmarinic acid. These variations translate to important differences in pharmacological efficacy of the herb.

According to Luping Qu and Mark Widrlechner from the United State Department of Agriculture–Agricultural Research Service at Iowa State University, necessary research on Prunella vulgaris cultivation and genetics has been limited. The team published a new study in HortScience that provides in-depth information about the herb's genetics and recommendations for developing breeding lines. Using accessions originally collected from different geographical regions, the team investigated the breeding system of Prunella vulgaris by observing variation in floral morphology, time of pollen release, and self-seed set in bagged flowers and isolated plants.

Microscopic observation of seven accessions, including ones with both exerted and inserted styles, revealed that they all release pollen to some degree before the flowers open. "Using bagged flowers, we found that self-seed set varied widely among eight accessions, ranging from 6% to 94%. However, bagging may underestimate seed set for some accessions," Qu and Widrlechner said. "The two accessions with the lowest rates when using bagged flowers increased in seed set by 350% and 158%, respectively, when we evaluated single, unbagged plants in isolation cages. The accession with 6% self-seed set when bagged also had exerted styles." They added that their results suggest that the mating system in P. vulgaris may be geographically structured or in the process of evolutionary change.

The study contains recommendations for development of pure breeding lines and creation of F1 hybrids. Qu and Widrlechner added that using observations of pollen-tube growth to evaluate possible mechanism(s) of self-incompatibility and artificial pollination to document outcrossing differences among accessions would produce more in depth knowledge of the breeding system of Prunella vulgaris and also be useful for genetic improvement efforts.


The complete study and abstract are available on the ASHS HortScience electronic journal web site:

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Original Article:

Variation in the Breeding System of Prunella vulgaris L.
Luping Qu and Mark P. Widrlechner
HortScience 46:688–692. [Abstract][Full Text][PDF]

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