Effect of aluminum concentration on growth and secondary metabolites production in three chemotypes of Cunila galioides Benth. medicinal plant

Abstract

Medicine plants play an important role in public health, especially in developing countries, and among them Cunila galioides Benth. is a naturally occurring medicinal and aromatic plant native from south Brazil. Flavonoids, present in significant amounts in some species of Cunila sp., possess several properties and its content may be affected by aluminum stress. In this context, the aim of this work was to assess the influence of different levels of aluminum in nutrient solution on the growth and content of essential oils and flavonoids in three chemotypes of Cunila galioides. The plant parameters evaluated were aerial dry matter, dry root matter, root length, root score, calcium and aluminum concentrations in the vegetable tissue, flavonoids content as well as essential oil yield and its major components concentration. Results showed that the addition of 30.0 mg.L--1 of Al3+ to the nutrient solution leads to a decrease of all agronomic parameters evaluated with losses in the cultivation yield for the greatest concentration studied. The André da Rocha population was found to be the most tolerant to aluminum while Bom Jardim da Serra was the most sensitive. The aluminum concentration did not influence the extraction yield as well as the content of major components in the oils. The concentration of flavonoids increased significantly for the populations tolerant to aluminum concentration in the nutrient solution, thus indicating a relationship between tolerance and flavonoids production, which may be an interesting characteristic from the medicinal point of view.