%0 Journal Article
%T Glyphosate translocation in herbicide tolerant plants Transloca  o do glyphosate em plantas tolerantes ao herbicida
%A L Galon
%A E.A Ferreira
%A I Aspiaz¨²
%A G Concen£¿o
%J Planta Daninha
%D 2013
%I Sociedade Brasileira da Ci¨ºncia das Plantas Daninhas
%R 10.1590/s0100-83582013000100021
%X The objective of this study was to evaluate glyphosate translocation in glyphosate-tolerant weed species (I. nil, T. procumbens and S. latifolia) compared to glyphosate-susceptible species (B. pilosa). The evaluations of 14C-glyphosate absorption and translocation were performed at 6, 12, 36 and 72 hours after treatment (HAT) in I. nil and B. pilosa, and only at 72 HAT in the species T. procumbens and S. latifolia. The plants were collected and fractionated into application leaf, other leaves, stems, and roots. In S. latifolia, approximately 88% of the glyphosate remained in the application leaf and a small amount was translocated to roots at 72 HAT. However, 75% of the herbicide applied on T. procumbens remained in the leaf that had received the treatment, with greater glyphosate translocation to the floral bud. It was concluded that the smaller amount of glyphosate observed in S. latifolia and T. procumbens may partly account for their higher tolerance to glyphosate. However, I. nil tolerance to glyphosate may be associated with other factors such as metabolization, root exudation or compartmentalization, because a large amount of the herbicide reached the roots of this species. Objetivou-se neste estudo avaliar a transloca  o de glyphosate em plantas tolerantes (Ipomoea nil, Tridax procumbens e Spermacoce latifolia) e suscet¨ªvel (Bidens pilosa) a esse herbicida. As avalia  es de absor  o e transloca  o do 14C-glyphosate em I. nil e B. pilosa foram efetuadas ¨¤s 6, 12, 36 e 72 horas ap¨®s a aplica  o do herbicida (HAT), e em T. procumbens e S. latifolia, ¨¤s 72 HAT. As plantas foram coletadas e fracionadas em: folha de aplica  o, demais folhas, caules e ra¨ªzes; em T. procumbens e S. latifolia, avaliou-se a presen a do produto na infloresc¨ºncia da planta. Em S. latifolia, aproximadamente 88% do glyphosate permaneceu na folha de aplica  o, e pequena quantidade translocou para as ra¨ªzes. Todavia, em T. procumbens, 75% do herbicida permaneceu na folha que recebeu a aplica  o, observando-se maior transloca  o na infloresc¨ºncia em rela  o ¨¤s ra¨ªzes. Conclui-se que a menor transloca  o do glyphosate observada em S. latifolia e T. procumbens pode ser um dos fatores respons¨¢veis pela maior tolerancia dessas esp¨¦cies ao herbicida, ao passo que em I. nil a metaboliza  o, a exsuda  o radicular ou a compartimentaliza  o podem favorecer a tolerancia, j¨¢ que grande quantidade do produto atingiu as ra¨ªzes da esp¨¦cie.
%K Ipomoea nil
%K Tridax procumbens
%K Spermacoce latifolia
%K Bidens pilosa
%K Ipomoea nil
%K Tridax procumbens
%K Spermacoce latifolia
%K Bidens pilosa
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000100021