Cross resistance to ALS-inhibiting herbicides in Euphorbia heterophylla L. biotypes resistant to imazethapyr.
Commun Agric Appl Biol Sci
; 68(4 Pt A): 335-9, 2003.
Article
em En
| MEDLINE
| ID: mdl-15149128
The effect of weeds on the diminution of agricultural production is considered to be between 30 and 50%. Imazethapyr is a herbicide which acts on the enzyme ALS, the first common enzyme in the biosynthetic pathway of valine, leucine and isoleucine. Euphorbia heterophylla is a common species in soybean fields in Brazil and different populations resistant to herbicides of the sulfonylurea and imidazolinone groups are currently being reported. The objectives of this work were: to determine the resistance of three different biotypes named RI, RII and RII to the herbicide imazethapyr: to establish the level of resistance to this herbicide, and to evaluate the behaviour of the biotypes to other herbicides with a similar mode of action. The response of plants treated with imazethapyr confirmed the existence of resistance in the biotypes denominated as RI, RII and RIII. The imazethapyr concentration required to reduce the activity of the enzyme ALS by 50% (I50) should be greater than 500 microM for biotypes RI, RII and RIII and 39.47 microM for the susceptible biotype. Applications made in the greenhouse at field doses of ALS inhibiting herbicides showed cross resistance in the case of imazamox and imazamethabenz but not in the cases of the other ALS inhibitor herbicides used. ALS activity results demonstrated that the imazethaphyr resistance in different biotypes of E. heterophylla is target site mediated.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Euphorbia
/
Herbicidas
/
Ácidos Nicotínicos
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Commun Agric Appl Biol Sci
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Colômbia
País de publicação:
Bélgica