Selection of material for cultivation in Aloysia polystachya (Gris.) Mold.

Aloysia polystachya,a (Gris.) Mold., local name "te de burro" (Spanish), is an aromatic native plant which is being wiped out from wild environments, whose culture has been started. In order to select material for growing, se eds were collected from two wild populations, one of them near Canada Luque in the north of Cordoba province (labeled B) and the other near Patquia, L a Rioja province (labeled N). Specimens of both populations were identified in the Botanical Museum of Facultad de Ciencias Exactas, Fisicas y Natural es of Universidad Nacional de Cordoba. Starting from those seeds, 250 plant s of each population were obtained and then grown in field conditions in Ri o Primero, Cordoba province (Llao Llao nursery garden), in thoroughly sandy soil, with 500 mm of additional irrigation and 210 kg/ha of urea fertiliza tion applied in spring-summer. From each population, clones were selected according to growth habit and dr y leaf production. Up to date, 6 clones of B population and 5 of N populati on have been isolated. Essential oil was extracted from each clone and the following yields, expressed as mi of essential oil per 100 g of dry leaves, were obtained: B-1 = 4.58%, B-3 = 3.93%; B-4 = 4.35%; B-5 = 4.40%; B-6 = 4 .84%; B-7 = 3.46%; N-1 = 2.28%; N-2 = 1.55%; N-3 = 3.58%; N-4 = 2.20% and N -5 = 2.17%. A qualitative and quantitative analysis by gas chromatography ( GC) and mass spectroscopy (GC-MS) was performed over each essential oil. Ac cording to this result, the main component in B clones is carvone (7478%) w hile the main component in N clones is alpha-thujone (60-74%). A remarkable difference between both populations is observed as much in essential oil y ield as in main components. The leaf yield is about 3,000 kg/ha in dry leav es for each population. Studies to quantify the dry leaf production of each clone are underway.