Characterization and evaluation of twelve oregano genotypes cultivated in the main areas of production of Argentina

TORRES, LORENA; BRUNETTI, PAULA; CHAVES, GUADALUPE; OCAÑO, SONIA; MASSUH, YAMILE; OJEDA, MARTA

Halifax

Congreso; Plant Canada - Plant Adaptation to Environmental Change; 2011

Canadian Society of Agronomy; Canadian Society of Horticultural Science; Canadian Society of Plant Physiologists; Canadian Botanical Association; Canadian Phytopathological Society and Canadian Weed Science Society.

In Argentina, oregano (Origanum spp.) is one of the most important aromatic species, which leaves and flowering tops are used as seasoning, targeting the retail consumer, industrial and less to export. Local production has low average yields due to the variability of cultivated material, the vegetative propagation methods used and the lack of knowledge and adaptative experimentation on advanced cultivation practices. In order to characterize the germplasm of oregano used in Argentina and to determinate the inter and intra-population variation existing for traits of agronomic importance, the collection of clones of oregano grown in the country was carry out. Conditions for the establishment of in vitro culture, sanitation by meristems culture and micropropagation for 19 clones of oregano were adjusted. It was possible to recover clones of oregano, which due to the successive cycles of vegetative propagation, were disappearing from the fields of production. It was also possible to generate a collection of germplasms in vitro consisting of 12 clones of oregano of different origins. Theses clones were field evaluated at three different locations, showing genotype x environment interaction for the most of the variables. Regardless of growing location, the quantitative variables with more discriminating value were essential oils yield, internode length, length of the longest branch, fresh weight, dry weight of leaf and stem, leaf/stem ratio and leaf area. With regard to qualitative variables, those with the largest discriminant value were leaves color, stem color, color of bracts, flower color, growth habits, flowering time and spike length. Depending on the variables analyzed oregano clones could be classified into four groups. Finally, it was determinate that the evaluated clones belong to three different taxa: Origanum vulgare ssp vulgare, Origanum vulgare ssp hirtum and Origanum x majoricum (hybrid). Within each group, the clones belong to the same taxon.