An Improved 2-step Liquid Culture System for Efficient In Vitro Shoot Proliferation of Sundew (Drosera rotundifolia L.)

An efficient procedure for in vitro shoot production of the medicinal plant sundew (Drosera rotundifolia L.) was developed. Of three cytokinins tested, zeatin (ZEA) at a concentration of 2 μM resulted in the formation of large numbers of adventitious shoots on leaf explants. A larger size of the small shoots was achieved by combining a 2-weeks preculture with ZEA (step 1: shoot induction) with a 5-weeks main culture without plant growth regulators (step 2: shoot elongation). Liquid media were superior to semisolid media: An average of 27.4 shoots per leaf explant, and 53.3 shoots per shoot explant were achieved. The 2-step culture system with liquid media permits a comparatively cheap micropropagation of sundew as well as in vitro biomass production, with potential for scale-up

Variations of Naphthoquinone Levels in Micropropaaated Drosera Species In Vitro, under Qreenhouse and Outdoor Growth Conditions

The naphthoquinone levels in clones of the sundew species Drosera communis, D. madagascariensis, D. peltata and D. rotundifolia were determined under in vitro, green house, and outdoor growth conditions. D. rotundifolia revealed a lower naphthoquinone content in vitro which rose upon transfer ex vitro. D. communis and D. madagascariensis exhibited higher levels in vitro which decreased in the greenhouse and further under outdoors conditions. Decreased naphthoquinone levels were found in D. peltata when in vitro cultures were moved to the greenhouse, which increased again when the plants were cultivated outdoors. The results underline that in the cultivation of the medicinally useful carnivorous genus Drosera species-specific differences in the biosynthesis of secondary metabolites under different environmental conditions have to be taken into consideration

Lignan formation in hairy root cultures of Edelweiss (Leontopodium nivale ssp. alpinum (Cass.) Greuter)

AbstractA hairy root line of Edelweiss (Leontopodium nivale ssp. alpinum (Cass.) Greuter) was obtained upon transformation with Agrobacterium rhizogenes strain ATCC15834. Elicitation of this line with silver nitrate, sucrose, methyl jasmonate and yeast extract at various concentrations in most cases resulted in a stimulation of lignan biosynthesis. Through elicitation with 6% sucrose the roots accumulated the pharmacologically active lignans leoligin and 5-methoxy-leoligin at levels of 0.0678% and 0.0372%, respectively, without significant growth inhibition. These lignan levels were comparable to those found in intact roots of cultivated Edelweiss. The biotechnological production of leoligin could be an attractive option for the continuous, field culture-independent production of the valuable secondary metabolites leoligin and 5-methoxy-leoligin

Swertia Chirata Buch.-Ham. ex Wall. (Gentianaceae), an Endanaered Himalavan Medicinal Plant: Comparative Study of the Secondary Compound Patterns in Market Drua. In Vitro-Cultivated, and Micropropaaated Field Qrown Samples

Samples of the Himalayan medicinal plant Swertia chirata obtained from a local market in Nepal, from a micropropagated field cultivated clone, and from two in vitro-clones were compared by means of HPLC. The substance patterns of methanolic and dichloromethane extracts of the in vivo grown materials showed good conformity while in the samples from tissue culture major compounds were missing. Our findings confirm that the secondary metabolism of in vitro-cultivated plants normally differs from that of plants in their natural environment. Furthermore, the compound pattern of plants produced through micropropagation and subsequently cultivated in the field is comparable to that of plants collected from the wild. As an alternative to the uncontrolled depletion of the natural resources a sustainable use of Swertia chirata could hence be achieved by controlled field culture of micropropagated plants