ABSTRACT. The elucidation of the resistance mechanism of weeds to herbicides is important for management practices. The objective of this work was to investigate the resistance mechanism of glyphosate-resistant C. sumatrensis biotypes by determining the expression levels of the constitutive gene epsps and two ABC transport protein-coding genes designated m7 and m11 with RT-qPCR. Two biotypes of C. sumatrensis were evaluated: one resistant and one susceptible to glyphosate. The treatments consisted of the absence or application of two doses of glyphosate (1,080 and 8,640 g a.e. ha-1). Plant leaves were collected at 1 and 4 days after herbicide application. No difference was observed in epsps gene expression between the studied biotypes. The expression of the m7 and m11 genes revealed that both genes had higher relative expression in the resistant biotype with the application of glyphosate at both doses. The overexpression of the m7 and m11 genes in the resistant biotype treated with glyphosate reveals that these genes play a role in herbicide resistance. These genes may be involved in the sequestration of glyphosate into the vacuole lumen in the resistant C. sumatrensis biotype studied.

RESUMO Avaliaram-se as doses de nitrogênio 0, 60, 120 e 240kg ha-1 sobre a composição bromatológica e os parâmetros da cinética de degradação ruminal da aveia branca obtida de dois anos de cultivo (2013-2014). Foram realizadas as análises de matéria seca, matéria mineral (MM), proteína bruta (PB), extrato etéreo, fibra em detergente neutro (aFDNmo), lignina, carboidratos solúveis (CHOs) e proteína insolúvel em detergente ácido (PIDA). Não foi observado efeito da adubação nitrogenada sobre as variáveis em nenhum dos anos de cultivo. As variáveis bromatológicas foram influenciadas pelos fatores ambientais. A cinética de degradação ruminal foi correspondente à composição bromatológica. No ano de 2013, foram observados valores superiores para as variáveis PB, MM, PIDA, CHOs e carboidratos não fibrosos, o que influenciou positivamente nos parâmetros da cinética de produção de gás in vitro, Vf 1 e k 2. A composição da cultivar em 2014 tendeu a maiores teores de aFDNmo, lignina e carboidratos totais e a valores superiores para os parâmetros Vf 2 e L. O parâmetro k 1 não foi significativo nos períodos avaliados. Em 2014 o valor nutritivo foi negativamente influenciado pelo atraso na semeadura e pela soma de períodos de restrição hídrica combinados com a elevação da temperatura.

ABSTRACT Doses of Nitrogen were evaluated: 0, 60, 120 and 240kg ha-1 on the chemical composition and rumen degradation kinetics of white oats obtained from two consecutive years (2013-2014). For nutritional characterization the following parameters were analyzed: dry matter; ash, crude protein, ethereal extract, neutral detergent fiber, lignin, soluble carbohydrates and insoluble acid detergent protein. No effect of nitrogen fertilization was observed on the variables analyzed in any of the growing years. The nutritional variables were influenced by environmental factors that occurred in the respective experimental periods and the parameters of ruminal degradation kinetics corresponded to the effects in these compounds. In year 2013, higher values were observed for the variables crude protein, ash, insoluble acid detergent protein, soluble CHO and no fibrous carbohydrates, resulting in higher values also for the in vitro gas production kinetics, Vf1 and k2. Nutritional contents in 2014 tended to higher levels of NDF, lignin and total carbohydrates, and higher values for the parameters Vf2 and L. The parameter k1 was not significant in any of the experimental periods evaluated. In 2014 the forage has its nutritive value negatively influenced by the delay in sowing and the periods of water restriction combined with higher temperatures.

Determinaram-se as exigências nutricionais de metionina+cistina digestível para poedeiras de linhagem comercial no segundo ciclo de produção de 75 a 91 semanas de idade, utilizando-se 150 aves semipesadas em delineamento inteiramente ao acaso. Estas foram distribuídas em cinco tratamentos, seis repetições e cinco aves por unidade experimental, alimentadas com uma dieta basal contendo 2.859kcal/kg de energia metabolizável e 16,30% de proteína bruta, suplementada com 0,132; 0,173; 0,215; 0,256 e 0,298% de DL-metionina (98%), de forma a proporcionar 0,588; 0,628; 0,669; 0,709 e 0,750% de metionina+cistina digestível na dieta. A inclusão de metionina+cistina obedeceu, respectivamente, às proporções de 67, 72, 77, 81 e 86% com a lisina fixada em 0,872%. Avaliaram-se os consumos de ração e de metionina+cistina, a conversão alimentar por dúzia e por massa de ovos, a taxa de postura, o peso e a massa de ovos, a porcentagem dos componentes dos ovos e a qualidade interna dos ovos e o ganho de peso. A inclusão de metionina+cistina digestível nas quantidades indicadas não exerceu efeito (P>0,05) sobre as características de produção e qualidade interna e externa dos ovos. A exigência estimada foi de 0,588% de metionina+cistina digestível, correspondendo ao consumo de 654,73mg/ave/dia.

This work determined the nutritional requirements for methionine + cystine for commercial hens in the second production cycle from 75 to 91 weeks of age, using 150 brown-egg layer hens in a completely randomized design, distributed in five treatments, six replicates of five hens each and fed a basal diet containing 2859kcal/kg of metobolizable energy, 16.30% crude protein supplemented with 0.132, 0.173, 0.215, 0.256 and 0.298% DL-methionine (98%), in order to provide 0.588, 0.628, 0.669, 0.709 and 0.750% methionine + cystine in the diet. The inclusion of methionine + cystine followed, respectively, the proportions of 67, 72, 77, 81 and 86% with lysine fixed at 0.872%. The feed intake, methionine + cystine intake, feed conversion per dozen eggs and egg mass, percentage of the eggs, egg weight, egg mass, percentage of egg components and internal quality of eggs and weight gain were evaluated. The inclusion methionine + cystine in the amounts indicated had no effect (P> 0.05) on the production characteristics and internal and external quality of eggs. The requirement was estimated at 0.588% methionine + cystine intake corresponding to 654.73mg/hen/day.