The genetics of artemisinin content in Artemisia annua L. and the breedingof high yielding cultivars

Artemisinin, the endoperoxide sesquiterpene lactone produced by the Chinese medicinal herb Artemisia annua, is very difficult to synthesise. Moreover, its production by mean of cell, tissue or organ cultures is very low. Pres ently, only its extraction from cultivated plants is viable. A large variat ion in artemisinin content has been observed in the leaves of plants from d ifferent origins. The genetic basis of this variation has been assessed and evidence for a quantitative inheritance of the artemisinin concentration p resented. Additive genetic components were predominant, resulting in a high narrow-sense heritability estimate. Thus, goods results can be expected fr om mass selection for the breeding of lines of Artemisia annua rich in arte misinin. Yet, dominance variance is also present in the total genetic varia bility, indicating that crosses between selected genotypes should generate progenies with particularly high artemisinin content. As a matter of fact, selection and crossing, in wild populations, of genotypes with high artemis inin concentration resulted in hybrid lines containing up to 1.4 % artemisi nin (on dry leaves basis).