ABSTRACT
The objective of this work was to carry out the in vitro establishment of Echynochloa polystachya aiming at obtaining a micropropagation protocol for works involving the selection of superior genotypes and the cultivation of the species. E. polystachya stems were collected in the municipality of Manaus-AM. Explants were inoculated in test tubes containing Murashige and Skoog (MS) medium. Thirty days after in vitro establishment, the rate of sprouting and contamination were evaluated. Experiments were also carried out to assess the effects of sucrose and 6-benzylaminopurine (BAP) concentrations on the tillering rate of explants. It was found that during the successive subcultures there was a decrease in internodes and the consequent loss of vigor. There were responses in the multiplication rate at concentrations starting from 45 g L-1 sucrose. In addition, BAP and sucrose interfered the development and in vitro multiplication. Sucrose in conjunction with BAP was harmful and shortened internodes. The physiological state of the explants for the species under study was intrinsically linked to the concentrations of sucrose used for the culture medium and the concentrations of BAP. However, the sucrose and BAP concentrations suggested for in vitro cultivation of E. Polystachya must be adjusted during successive subcultures. Absence of contamination in the in vitro establishment occurred at concentrations 15, 30 and 60 g L-1 sucrose. The combination of 1.5 mg L-1 BAP and 30 g L-1 sucrose promoted greater induction of sprouts. In addition, the in vitro rooting of E. polystachya was 45%.
Subject(s)
In Vitro Techniques , Brachiaria , Tissue Culture TechniquesABSTRACT
Objetivou-se com o estudo avaliar o efeito de aditivo enzimo-bacteriano e de uréia sobre a degradabilidade ruminal e o fracionamento de carboidratos em silagens de grama estrela. Foram avaliadas silagens sem aditivo (SGE) e com aplicação de aditivo enzimo-bacteriano (SGE150 e SE300, respectivamente 150 e 300g aditivo/tonelada) e uréia (SGEU, 10 kg/tonelada). Para o ensaio de degradabilidade foram utilizados três bois da raça Holandesa distribuídos em blocos casualizados. A degradabilidade efetiva (DE) da MSe da FDN foram maiores para o tratamento SGE300 em todas as taxas de passagem. Para a DE da PB houve diferença (P<0,05) para o tratamento SGEU. Os carboidratos totais (CHT) tiveram os maiores valores para o tratamento SGE, enquanto que, para as frações A+B1 e B2 não houve efeito significativo entre os tratamentos. Para a fração C os menores valores foram para os tratamentos com inoculante. Conclui-se que a aplicação do inoculante ou uréia não melhoraram a degradabilidade potencial (DP) das silagens de grama estrela em relação ao tratamento isento da aplicação de inoculante.
It was aimed to evaluate in this trial the effect of additive and urea supplies on ruminal degradabilty andcarbohydrates fractioning of stargrass silages. There were evaluated silage without additive (SGE),silage with enzymatic-bacterial additive (SGE150 and SGE300 respectively, 150 and 300 g of additive/tonof silage) and silage with urea (SGEU, 10 kg/ton). Three Holstein steers were used in blocks randomizedsdesign for ruminal degradability assay. The effective degradability (ED) of DM and NDF were higher(P<0.05) for SGE300 treatment for all flow rates. There was difference (P<0.05) for ED of CP in silagesupplied with urea. Total carbohydrates presented the highest values for no additive treatment, whileA+B1 and B2 fractions didnt differ (P>0.05) among treatments. Silages with additive presented thelowest values (P<0.05) of C fraction. It was concluded that additive or urea supply in stargrass silagesdidnt improve the potential degradability (PD) when compared to the silage without additive.