Multiple resistance to atrazine and imazethapyr in hairy beggarticks (Bidens pilosa )

• Published in: Ciência e agrotecnologia 2016-10, Vol.40 (5), p.547-554
• Main Authors: Takano, Hudson Kagueyama, Oliveira Junior, Rubem Silvério de, Constantin, Jamil, Braz, Guilherme Braga Pereira, Franchini, Luiz Henrique Morais, Burgos, Nilda Roma
• Format: Article
• Language: English
• Subjects: AGRICULTURE, MULTIDISCIPLINARY; herbicide resistance; Photosystem II; resistance level
• ISSN: 1413-7054; 1981-1829; 1413-7054
• DOI: 10.1590/1413-70542016405022316

ABSTRACT Resistance to herbicides is a serious threat to crop production worldwide, especially in agronomic crops and cereals. This research evaluated the possible occurrence of Bidens pilosa resistant to imazethapyr and atrazine in Brazil. The resistant biotype was collected from an area with a history of repeated application of photosystem II (PSII) and ALS inhibitor herbicides. The susceptible biotype was collected from an area with no history of herbicide application. Resistance verification experiments were carried out in the greenhouse. The treatments were arranged in a 3 x 8 factorial scheme, where the first factor was populations [susceptible (S), parent resistant (PR), and resistant F1 (RF1)]; and the second factor was herbicide dose (0, 375, 750, 1500, 3000, 6000, 12000 and 24000 g ha-1 for atrazine; or 0, 12.5, 25, 50, 100, 200, 400 and 800 g ha-1 for imazethapyr). The resistance factor to atrazine was 2.83 for PR and 5.55 for RF1. This population was more resistant to imazethapyr (>21-fold) than it was to atrazine. The recommended maximum dose of the herbicides did not control this B. pilosa population adequately. The data support the claim that B. pilosa population from this field in Quarto Centenário, Parana is resistant to two herbicide modes of action - PSII inhibitor (i.e. atrazine) and ALS inhibitor (i.e. imazethapyr). This is the first report of such case for this species, globally. Cross-resistance to other ALS inhibitors and other PS II inhibitors as well as the respective mechanisms of resistance to each herbicide are being investigated. RESUMO A resistência de plantas daninhas à herbicidas constitui uma das principais ameaças para a agricultura no mundo, especialmente para a produção de grãos. O presente trabalho objetivou verificar a possível existência de Bidens pilosa resistente a imazethapyr e atrazina. Dois experimentos foram realizados em casa-de-vegetação, sendo um para cada herbicida. O biótipo resistente foi proveniente de área com histórico de aplicações de herbicidas inibidores do fotossistema II e da ALS, enquanto que o biótipo suscetível foi coletado em área sem histórico de aplicação de herbicidas. Os tratamentos foram dispostos em esquema fatorial 3 x 10, em que o primeiro fator foi composto por diferentes populações [suscetível (S), resistente parental (RP) e resistente F1 (RF1)], e o segundo fator constituiu de doses de cada herbicida (0, 375, 750, 1500, 3000, 6000, 12000 and 24000 g i.a. ha-1 para atrazina e 0; 12,5