Resumo

ROMAGNOLI, María V.; TUESCA, Daniel  e  PERMINGEAT, Hugo R.. Caracterización de la resistencia de Amaranthus quitensis a tres familias de herbicidas. Ecol. austral [online]. 2013, vol.23, n.2, pp.119-125. ISSN 1667-782X.

Characterization of Amaranthus quitensis resistance to three families of herbicides: Amaranthus quitensis is an annual species from South America that reproduces by seed. In Argentina its distribution covers central and northern country and is a major weed of summer crops (soybean, corn and sunflower) Pampa area. In the central region (Province of Cordoba and Santa Fe) flaws in its control were detected, when using different herbicide families (imidazolinone, sulfonylurea and triazolopyrimidines). Therefore, the aim of this study was to characterize the resistance at the biochemical and molecular level of biotypes of A. quitensis from four localities along this region. Specifically we used different herbicides inhibitors Aceto-Lactate Synthase (ALS), an enzyme involved in the synthesis of a group of aminoacids, and compared them with a susceptible biotype. Specific objectives were to determine the geographical origin of the resistance to each of these three herbicides and to assess the effect of different doses on ALS activity in vitro. Results, based on the observed genetic variability and on the sequences of the als genes, indicated that the analyzed populations were originated independently and not from a common mutation event that later dispersed to the different sites. These results allowed for a deeper knowledge at the biochemical and molecular levels of the resistance mechanisms of five ecotypes of A. quitensis to different herbicides that have the ALS enzyme as a target.

Palavras-chave : ALS; Acetolactate synthase resistance; Biodiversity; Agroecosystems.

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