Articles
RECURSOS FITOGENÉTICOS RELACIONADOS CON EL CULTIVO Y EXPLOTACIÓN DE LA YERBA MATE (ILEX PARAGUARIENSIS ST. HIL., AQUIFOLIÁCEAS) EN EL CONO SUR DE AMÉRICA
Hil. (Aquifoliaceae), an evergreen holly.
It is either planted, or harvested from wild trees from the subtropical rainforests, at Brazil, Paraguay and Argentina.
In this last country, the world’s leading producer and consumer of maté, has been extensively planted since 1903, overcoming problems such as the natural low germination rates of its seeds.
From 1930’s onwards, overproduction of fresh maté for the yerba mate industry, has led to regulatory legislation and progressively better quality control procedures upon raw materials, thus restricting misuse of alternatives Ilex species, such as I. dumosa Reissek, I. theezans C. Martius ex Reissek, etc., then involved in the industrial preparation of maté.
On the other hand, market demands for uniformity concerning both quality and higher yields, have induced to start in 1974 several plant selection programmes, notably clonal propagation and interclonal breeding of selected superior progenitor trees.
This fact, which obviously restricts genetic variation of a given crop species, is accompanied by a high-scale deforestation process occurring in almost the whole of Ilex paraguariensis’ natural distribution area.
In spite that Ilex L. has about 220300 representatives in the rich South American native flora, hardly a dozen sympatric species occur within and/or the neighbourhood of Ilex paraguariensis‘ wild distribution area (i.e.
Southern Brazil, Eastern Paraguay and Northeastern Argentina). This region originally almost completely covered by subtropical rainforests, which housed not only Ilex paraguariensis and its relatives –Ilex brasiliensis (Spreng.) Loes., I. brevicuspis Reissek, I. dumosa Reissek, I. microdonta Loes., I. taubertiana Loes., I. theezans C. Martius ex Reissek, Ilex affinis Gardner, I. chamaedryfolia Reissek, I. integerrima (Vell.
Conc.) Loes. and I. pseudobuxus Reissek-, but also a great variety of beneficial animals such as insects involved on Ilex pollination and seed propagating birds, is nowadays a rich agroforestrial area.
Extensive crops, such as maize, soybean, wheat, Paraná pine, etc., and also cattle breeding, have replaced such original rainforests housing Ilex spp., thus enhancing a deep erosion process of the plant genetic resources for the maté crop.
Consequently, efforts have been done by the INTA (the governmental leading Argentinean Agricultural Research Institution) at the Cerro Azul Experimental center (province of Misiones, Argentina) in order to collect and preserve alive specimens, not only from different geographical origins of Ilex paraguariensis, but also of another wild Ilex species.
Although it has not yet been possible to find alive Ilex affinis Gardner individuals, Ilex argentina Lillo, a wild taxon from NW Argentina with an historical record as regional substitute of genuine maté, is also grown at Cerro Azul.