Germplasm release of four high-artemisinin clones of Artemisia annua L.

Authors: WETZSTEIN, HAZEL - Purdue University; JANICK, JULES - (NCE, CECR)networks Of Centres Of Exellence Of Canada, Centres Of Excellence For Commercilization A; Ferreira, Jorge

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2019
Publication Date: 11/12/2019
Citation: Wetzstein, H.Y., Janick, J., Ferreira, J.F. 2019. Germplasm release of four high-artemisinin clones of Artemisia annua L. HortScience. 54(11):2081-2082. https://doi.org/10.21273/HORTSCI14385-19.
DOI: https://doi.org/10.21273/HORTSCI14385-19

Interpretive Summary: Malaria kills millions worldwide, victimizing approximately 3,000 children/day, mainly under the age of five, and causing billions of dollars in lost wages by debilitating working adults in afflicted countries who eventually die if left untreated. Eliminating malaria is critical to achieve sustainable development in those countries and would allow their participation in global development projects. As most people in developing countries cannot afford antimalarial drugs, subsidized antimalarial medicine is vital to keep the disease under control and reduce morbidity and mortality in the population. One of these subsidized medicines is artemisinin-combination therapy (ACT), sanctioned by WHO since 2004, in which an artemisinin-derived drug is combined with a second (sister) drug that increases efficacy of ACT and reduces the risk of resistance by the malarial parasite. The only commercial source of artemisinin is the plant Artemisia annua, which has been cultivated in Africa and Asia to provide artemisinin as raw material for the manufacture of ACT. Because the plant reproduces through seeds from wind-pollinated plants or from artificially-pollinated parents, both commercial crops and wild-harvested crops produce plants with a large variation in leaf-artemisinin concentration (average 0.8% artemisinin as leaf dry weight). Our work involved plants from Brazilian and Chinese origin that were tested under field, greenhouse and tissue culture conditions and field-selected to produce high artemisinin (2.0% of leaf dry weight). These plants can more than double commercial artemisinin production when used as vegetatively propagated clones and can reduce the market price of artemisinin and of artemisinin-derived ACT. We hereby release our high-artemisinin clones to be used as parents in breeding programs that will result in new lines with higher artemisinin concentration than the ones currently available. The high-artemisinin clones can be an asset in both breeding and research programs destined to produce elite Artemisia germplasm to be distributed among farmers engaged in producing artemisinin as the raw material for antimalaria drugs such as ACT.

Technical Abstract: Malaria morbidity is currently on rise and artemisinin combination therapy (ACT) is still the only reliable line of treatment to cure quinine-resistant malaria and the only natural medicine to have a drastic impact on malaria control worldwide. However, commercial cultivars of Artemisia annua (the only commercial source of artemisinin) are only available from a couple of producers in the world and the price is steep for farmers in developing countries afflicted by malaria. Artemisia annua is the only commercial source of artemisinin and produces other compounds that are reported to enhance the antimalarial effect of artemisinin. Although China produces the most artemisinin for the manufacture of ACT, Africa has expanded the cultivation of annual wormwood since 2004. However, high-artemisinin cultivars are not easily available, and it is paramount that countries afflicted by malaria have access to high-artemisinin genotypes of A. annua. During several years, we have selected high-artemisinin genotypes of A. annua, among Brazilian and Chinese genotypes, that can produce from 1.6-2.0% artemisinin on a dry weight basis and high shoot biomass. One of the genotypes (C1) produced 2.16% artemisinin and 3.22 tons of dry leaves·ha-1, based on one plant·m2. Both shoot dry mass/ha and artemisinin can be significantly increased as more plants are used per m2, to a point. Our yield based on 1.0 plant.m2 was twice the average concentration of artemisinin currently reported for commercial cultivars and with estimated potential to produce 70.7 kg artemisinin·ha-1. Our selections were tested under field, greenhouse and tissue culture conditions, and field-selected for high artemisinin. These plants can more than double commercial artemisinin production when used as vegetatively-propagated clones and can reduce both the current market price of artemisinin and of artemisinin-derived ACT. We hereby release our high-artemisinin clones to be used as parents in breeding programs that will result in new lines with higher artemisinin concentration than the ones currently available. The high-artemisinin clones can be an asset in both breeding and research programs destined to produce elite Artemisia germplasm to be distributed among farmers engaged in producing artemisinin as the raw material for antimalaria drugs such as ACT.