A random collection of 700 plants of a seed-raised population of Artem
isia annua cv. Asha were screened for morphology and artemisinin and e
ssential oil contents. Four morphologically distinct plant types were
detected: short and early flowering, tall and early flowering, tall, a
nd late flowering, and dwarf and very late flowering. The artemisinin
and essential oil were largely present in the inflorescence of all the
types of plants. The artemisinin and the essential oil content in the
dried herb (inflorescence + leaves) of these plant types ranged from
0.001 to 0.11% and 0.14 to 0.60%, respectively; the late flowering pla
nts were generally richer in both artemisinin and the essential oil. E
leven individual adult plants were selected on the basis of their high
artemisinin yield and in vitro regeneration response to a micropropag
ation procedure using young inflorescence segments as explants. The mi
cro-cloned progenies of the selected plants were tested for their grow
th, morphology and artemisinin yield and homology in respect to these
characters with the respective parent selections. The parent-microprop
agated progeny characteristics were observed to be largely congruent.
The artemisinin profiles of the micropropagated progenies at vegetativ
e, preflowering and full bloom stages indicated that while highest art
emisinin accumulation occurred at full bloom stage, the artemisinin co
ntent at preflowering stage was positively correlated with that at ful
l bloom stage. Among the material cloned in vitro and tested in the fi
eld, clone numbers 166 and 187 yield 3.2- and 2.5-fold more artemisini
n per plant as compared to the parent cultivar Asha, the former due to
high herb yield and latter due to high artemisinin content per se. Co
pyright (C) 1996 Elsevier Science Ltd