Pelargonium sidoides DC and Pelargonium reniforme curtis are important medicinal species, harvested predominantly in the Eastern Cape of South Africa. The tubers of these plants are a rich source of phenolic acids, proanthocyanidins and coumarins which play a vital role in their useful properties. Their uses include the treatment of diarrhoea, dysentery, colds and bronchitis. P. sidoides has also been used in the treatment of tuberculosis.
The majority of the tubers are harvested for the export market. Recent estimates indicate over 4 million tubers exported annually, with an ever growing global demand in countries such as the United Kingdom, United States, Europe and Australia.
Field cultivation is virtually negligible and there is an increasing demand on wild growing populations. This has resulted in a serious depletion of the wild growing species, presenting a biodiversity threat to such an extent that there is a move to place these plant species in national protected and endangered species list.
This innovation offers a cultivation method to alleviate the pressure on these populations and provide quality stock for the medicinal industry.
The method of Pelargonium propagation on this innovation offers an ideal alternative source of important phyto-pharmaceutical products derived from P. sidoides. This method equally produces material with similar coumarin profiles to that of non-propagated material.
Through this strategy chemo-elite types may be maintained in continuous cultivation, lifting pressure off wild populations and increasing accessibility of key compounds for commercial product formulation. The plants produced easily transplant and grow efficiently under greenhouse conditions and within six months new tubers (3-5 per plant) may be established in the greenhouse.
The strategy developed allows for exponential production of disease-free plantlets through tissue culture.
Phyto-pharmaceutical companies who are dependent on wild harvesting and agricultural production of their material
● Offers a guaranteed, continuous supply of material
● May be used to establish plantlets and shorten the time to harvest tubers
● Allow for industrialisation with potential mass production in automated systems
● Sustainable, year round production of Pelargonium material
● Maintenance of product chemo-types for application as a phyto-pharmaceutical
● Reduced burden on wild population harvesting – a practice which could become illegal in the future – protecting the plant material for the future
This technology has been patented.
Prof Nokwanda Makunga, Department of Botany and Zoology, Stellenbosch University.
Dr. Janine Colling, Vibrational Spectroscopy Unit (CAF), Stellenbosch University.