Abstract
Using colchicine we induced tetraploidy in Artemisia
annua L. plants. During a vegetation period we monitored the time course
of the levels of artemisinin, its direct precursors, the biosynthetically
related sesquiterpenes and the essential oil content in the diploid (wild-type)
and tetraploid A. annua plants. The averaged
artemisinin level in tetraploids was 38 % higher than that of the wild-type
as measured over the whole vegetation period. In contrast, the averaged essential
oil content of the tetraploids over this period was 32 % lower. This
might suggest a reciprocal correlation between artemisinin (sesquiterpenes)
and the essential oil content (monoterpenes). The averaged biomass of the
leaves of the tetraploid plants was lower compared to the wild-type plants.
Therefore, the artemisinin yield per m2 tetraploids was decreased
by 25 %. Although the tetraploid plants were smaller than the wild-type
plants, certain individual organs like the leaves were considerably larger,
and seeds obtained by cross pollination between tetraploid
A. annua plants had a spectacular size. In principle, tetraploid A. annua can be a useful starting material for
a breeding program in order to obtain larger and faster growing plants, which
produce higher levels of artemisinin.
Key words:
Artemisia annuaL.
- Asteraceae - artemisinin - biosynthetic precursors - seasonal variation - sesquiterpenes - tetraploidy
