Selection and micropropagation of high artemisinin producing clones of Artemisia annua L.

Abstract

Abstract An in vitro micropropagation method has been used to clone Artemisia annua L. plants from axenic seedlings or field grown plants selected on the basis of morphological characteristics during the growing season. Clones were maintained in culture by continuous transfer every 4–6 weeks. The performance of the various clones in the field as well as their contents of artemisinin and related sesquiterpenes were compared with selected field grown plants. An internally standardized reverse‐phase HPLC method was developed for this evaluation. Artemisinic acid (III) was by far the major sesquiterpene for all clones tested, followed by arteannuin B (II) and then artemisinin (I). However, there was a high degree of variability between various clones for all sesquiterpenes tested. The high artemisinin producing clones are characterized as tall robust plants with long internodes, open branching, dense leaves and thick stems. Results from unorganized callus cultures initiated from the leaves of the corresponding clones did not indicate the formation of artemisinin or related sesquiterpenes in these cultures.