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New Artemisia annua Hybrids with High Artemisinin Content
annual wormwood, breeding, cultivar, malaria
Artemisinin, a sesquiterpene lactone endoperoxide isolated from the herb
Artemisia annua L. (Asteraceae), is a highly potent antimalarial compound, which is
efficient against multidrug-resistant strains of Plasmodium falciparum. The promotion
of artemisinin-based combination therapies (ACTs) by the WHO during the past years
lead to a strong pressure on the world market of artemisinin. The scarcity of arte-
misinin caused a price increase that strongly renewed the interest for Artemisia annua
culture at a large scale. The use of varieties with high artemisinin content is a key
factor for the development of such cultures. The new hybrids recently obtained by
Mediplant, with artemisinin contents nearing 2%, are being presented.
Artemisinin, a sesquiterpene lactone endoperoxid isolated from the herb Artemisia
L. (Asteraceae), is a highly potent antimalarial compound, which is also efficient
against multidrug-resistant strains of Plasmodium falciparum
(Alin, 1997). With the
support of the WHO, in 2005 over 53 countries have officially adopted artemisinin-based
combination therapies (ACTs) as their first line of treatment against malaria (WHO,
2006). The global consumption of ACTs has increased from a few hundred thousands in
2001 and 2002 to tens of millions treatments in 2005. The rapid increase in demand
produced a global supply shortage of artemisinin and a price increase. Despite the
research of new technologies (Hentschel, 2005), the extraction from A. annua
remains the only source of artemisinin. Only the distribution of varieties with a high
artemisinin production potential allows making this new culture attractive and this way
answer an increasing demand for low cost artemisinin (Ferreira et al., 2005). Research
conducted for about 15 years by Médiplant on the biology of A. annua
and the breeding
on artemisinin allowed to develop cultivars with over 1% artemisinin in the leaves
(Delabays et al., 1993, 2001). The breeding work continues to get new cultivars rich in
artemisinin and well-suited to the inter-tropical zone. The present paper presents the
results obtained with the latest hybrids created.
MATERIALS AND METHODS
Creation of the Hybrids
Plants issued from our breeding program and preserved in vitro (Lê and Collet,
1991) are raised in greenhouses with controlled day lengths to ensure floral induction.
Since the auto-fertilization being insignificant (Delabays, 1997), the plants are isolated in
groups of 2 genotypes to ensure the production of hybrid seeds.
Seeds obtained from the controlled cross were sown in greenhouses during March,
the hybrid seedlings were transplanted on field about mid-May in Conthey, Switzerland
(46°13’N latitude, 7°17’E longitude and 485 m asl) according to an experimental system
with 3 replications of 20 plants per elementary plots (density 1.78 plants/m2). Six central
plants per elementary plot were harvested around September 20 at vegetative stage and
dried at 35°C. The leaves are then separated from the stems and reduced to powder
Proc. XXVII IHC-S2 Asian Plants with Unique Hort. Potential
The determination of artemisinin content from the dry leaves powder was realised
with HPLC at Agroscope Changins-Wädenswil Research Station ACW according to the
method described by Delabays (1997) and Zhao and Zeng (1986).
RESULTS AND DISCUSSION
The results obtained with our reference cultivar ‘Artemis’ during 5 consecutive
years are given in Table 1. The values are stable with an average artemisinin content of
the leaves of 1.3%. The mean annual production of artemisinin was about 32 kg/ha
For five new hybrids of A. annua
, the artemisinin contents in their leaves were
very high varying from 1.60 to 1.95% (Table 2). After 4 months of field cultivation in
Swiss climatic conditions with the density of 17,800 plants/ha, these hybrids produced 2.1
to 2.85 t/ha dry leaves and 40.5 to 52.0 kg/ha artemisinin. One of the most promising new
hybrid, the Hybrid 1, revealed a similar yield in dry leaves, showing 36% higher content
of artemisinin in the leaves and 37% higher production of artemisinin compared to the
cultivar ‘Artemis’ in 2001 (Table 3).
The breeding work had been conducted by Mediplant since 1989 and was judged
to be successful based on the creation of high-yielding clones' hybrids. During the past 9
years, about 45 new hybrids were tested. A continuous breeding for cultivars with a high
artemisinin production has allowed this progression of the artemisinin content in the
leaves. Although the artemisinin content is the first selection criterion retained, other
factors such as the aptitude for in vitro conservation, the strength, the leaves productivity,
the flowering earliness and the tolerance to pests and diseases are also considered.
In order to validate their production potential, these new promising hybrids will be
tested over several years in Switzerland as well as in other various areas of the inter-
tropical zone which appear to the main production sites for artemisinin.
After the registration in 1999 of a first cultivar ‘Artemis’ with 1.3% artemisinin
content in the leaves, the latest results obtained by the cultivar breeding program let fore-
see at short term the launching of a new cultivar with a productivity gain of more than
The analysis were realised by the chemistry laboratory of the research station
Alin, M.H. 1997. In vitro susceptibility of Tanzanian wild isolates of Plasmodium
to artemisinin, chloroquine, sulfadoxine/pyrimethamine and mefloquine.
Delabays, N., Benakis, A. and Collet, G. 1993. Selection and breeding for high
artemisinin (Qinghaosu) yielding strains of Artemisia annua
. Acta Hort. 330:203-207.
Delabays, N. 1997. Biologie de la reproduction chez l'Artemisia annua
et génétique de la
production en artémisinine. Thèse de doctorat: Uni. de Lausanne.
Delabays, N., Simonnet, X. and Gaudin, M. 2001. The genetics of artemisinin content in
L. and the breeding of high yielding cultivars. Current Medicinal
Ferreira, J.F.S., Laughlin J.C., Delabays, N. and Magalhaes, P.M. 2005. Cultivation and
genetics of Artemisia annua
L. for increased production of the antimalarial
artemisinin. Plant Genetic Resources 3:206-229.
Hentschel, C. 2005. ACT pipeline & synthetic artemisinins. Coartem Advisory Board
Meeting, 10-11 March 2005, Dakar, Senegal.
Lê, C.L. and Collet, G.F. 1991. The in vitro culture of Artemisia annua
Zhao, S.S. and Zeng, M.Y. 1986. Application of precolumn reaction to high-performance
liquid chromatography of Qinghaosu in animal plasma. Anal. Chem. 58:289-292.
WHO. World Health Organisation. 2006. www.who.int.
Table 1. Yield and artemisinin content in the leaves of ‘Artemis’ for 5 consecutive years
Year Planting Harvesting Dry leaf yield Artemisinin content Artemisinin yield
1Newman-Keuls test; 2 ns: not significant (P>0.05).
Table 2. Yield and artemisinin content in the leaves of 5 new hybrids of Artemisia annua
ns2 ns ns 1planting date 25.05.2005 and harvesting date 21.09.2005; 2ns: not significant (P>0.05).
Table 3. Yield and artemisinin content of the cultivar Artemis and the new reference
1planting date 16.05.2001 and harvesting date 20.09.2001; 2Newman-Keuls test; 3ns: not significant
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