Enzymatic properties of cyperus difformis ALS enzyme and mechanism resistance of the species to pyrazosulfuron-ethyl herbicide [Propriedades enzimáticas da enzima ALS de cyperus difformis e mecanismo de resistência da espécie ao herbicida pyrazosulfuron-ethyl]
Dal Magro T.,Federal University of Pelotas |
Dal Magro T.,University of Caxias do Sul |
de Rezende S.T.,Federal University of Viçosa |
Agostinetto D.,Federal University of Pelotas |
And 2 more authors.
Ciencia Rural | Year: 2010
Cyperus difformis L. is a weed that occurs in flooded rice, which has presented difficulty in controlling due to the resistance to ALS inhibiting herbicides. The objectives of this research were to investigate kinetic characteristics of ALS enzyme from C. difformis biotypes and to determine the biochemical bases of resistance from the species to pyrazosulfuron-ethyl herbicide. For that, experiments were conducted at the BIOAGRO/UFV laboratory. The method used was based on the methodology used by CAREY et al. (1997) and adapted by VARGAS et al. (1999), with some modifications. It was evaluated substratum concentration (pyruvate) that provides initial velocity equal to half the speed reaction (KM) and maximum velocity of reaction (Vmáx), as well the activity of the ALS enzyme in the presence of the inhibitor (pyrazosulfuronethyl). According to the results, it is possible to observe that C. difformis resistance to pyrazosulfuron-ethyl is due to the insensibility of the ALS enzyme to the herbicide, however without penalty to KM and Vmáx kinetic parameters of the ALS enzyme.
Caierao E.,Embrapa Trigo CNPT |
Scheeren P.L.,Embrapa Trigo CNPT |
Silva M.S.,Embrapa Trigo CNPT |
Castro R.L.,Embrapa Trigo CNPT |
Cargnin A.,Embrapa Trigo CNPT
Ciencia Rural | Year: 2014
The wheat breeding program of Embrapa has an important role in the history of this cereal in Brazil, releasing more than one hundred new cultivars to different regions of the country in almost forty years of existence. However, is not possible assign its importance only to the number of cultivars, but also the impact of their germplasm in other brazilian wheat breeding programs. The objective of this study was to quantify the importance of Embrapa's germplasm in the brazilian wheat breeding programs. Were analyzed the genealogies of all wheat cultivars indicated for growth since 2005 and 2012, by institution. During the study period, the average participation of Embrapa's germplasm on cultivars of other institutions was 58.7%, with emphasis to Biotrigo Genética, CCGL TEC and OR Melhoramento de Sementes Ltda, respectively, in which use was 100%, 97.5% and 87.7%.