1/5/12, 11:34

Acetolactate synthase proline (197) mutations confer tribenuron-methyl resistance in Capsella bursa-pastoris populations from China

El propósito de esta investigaicón fue elucidar el mecanismo de resistencia que confiere resistencia a herbicidas inhibidores de la ALS en la maleza bolsa de pastor. Tal mecanismo de resistencia obedece a una mutación puntual en la secuencia nucleotídica del gen codificante de la enzima blanco.

Hai lan Cui, Xiangju Li, Guiqi Wang, Jianping Wang, Shouhui Wei, Hongyu Cao

Pesticide Biochemistry and Physiology, 102: 229–232 (2012)

The increasing use of AHAS-inhibiting herbicides has resulted in evolved resistance in key dicot weeds infesting cereal cropping systems worldwide. Shepherd’s purse (Capsella bursa-pastoris) is a common dicot weed species in wheat in China with populations that have evolved resistance to the AHAS herbicide tribenuron-methyl. The seeds of eight resistant populations were collected from wheat fields and one susceptible population from road side in Hebei province of China. All eight populations showed high level resistance to tribenuron-methyl with resistance indices of over 100 fold based on whole plant dose response assays in the greenhouse. Comparison of the AHAS gene sequences of the susceptible and resistant populations with Arabidopsis revealed that proline at position 197 of the AHAS gene was substituted by threonine in population CAPBU-HB-2, serine in populations CAPBU-HB-3, CAPBU-HB-4, CAPBU-HB-5, and CAPBU-HB-6, leucine in population CAPBU-HB-7 and CAPBU-HB-8, histidine in population CAPBUHB- 9. The study confirmed tribenuron-methyl resistance in shepherd’s purse in Hebei province of China due to target site mutations at AHAS codon position 197.