Enhancement of Artemisinin in Artemisia annua L. through Induced Mutation

Artemisia annua is the source of artemisinin, an antimalarial drug which is effective against multidrug-resistant strains of plasmodium, the malarial parasite. Malaria has serious effects on morbidity and mortality thus negatively impacting on agricultural production and food security. Although artemisinin has been found to be a useful medicine; its production is very low in comparison with what is actually needed to treat the worldwide threat of malaria. On the other hand, the lower content (0.01% - 0.8%, dry weight) of artemisinin found in leaves and flowers of A. annua has seriously limited its commercialization. Currently there are only two varieties of A. annua present in Kenya; hence there is a need to increase its diversity. The objective of the current study was to determine the effect of mutation on agronomical traits and artemisinin production by parents and mutant (M₂) A. annua plants in Kenya Agricultural and Livestock Research Organisation (KALRO) Njoro and the University of Eldoret (UoE). Seeds of two varieties of Artemesia annua varartemis and varanamed were sent to Vienna Austria for irradiation at the International Atomic Energy Agency (IAEA) at a dosage of 150 gray. The M₁ seeds were multiplied at the University of Eldoret farm. The harvested seeds were planted in replicate at the University of Eldoret and Njoro (KALRO). The results showed that mutation had significant effect on agronomical traits (P-value < 0.001). Mutant varieties and lines showed wide variation in terms of agronomical traits (crown length, stem length, plant height and stem diameter) and yield of artemisinin. The following lines showed superiority in artemisinin production; Artemis line 1, 2 and 9 with an average mean of 58.843, 58.393 and 69.192 μg/l, respectively while Anamed line 2, 3, 5 and 8 with an average of 56.268, 51.704, 53.557 and 54.448 μg/l, respectively. The effect of mutation on both agronomical traits and production of the artemisinin content appeared to occur randomly and was also dependent on environmental factors in the different ecological zones. Higher means in agronomical traits was observed in UoE while production of artemisinin content was enhanced in Njoro. The artemisinin yield in A. annua crops was negatively correlated with leaf traits, shoot and stem characteristics. Leaf traits had positive correlations with shoot and stem characteristics. It is recommended that superior lines be advanced in generations for further stability and evaluation of its efficacy in treatment of malaria.