9 research outputs found
Micropropagation of Pluchea sagittalis (Lam.) Cabrera
ABSTRACT:The objective of this study was to develop an in vitro protocol for the micropropagation of Pluchea sagittalis (Lam.) Cabrera. Plants were regenerated in vitro from stem segments. The procedure employed includes: 1) surface sterilization of shoots by immersion in 70% ethanol for 10 s followed by 1.0% NaOCl for 10 min, and subsequent immersion in 0.05% HgCl2 for 3 min and two washes with sterile distilled water; 2) induction of root and shoot by culture on hormone-free Murashige and Skoog medium (MS); 3) acclimatization of 60 day-old-plantlets in soil under ex vitro conditions. Minimum contamination was observed for apical shoot explants (10%). However, independently of the explant position in the stem, all explants regenerated new shoots. Various successive cultivations from stem explants every 60 days during more than 1 year have been shown to be a suitable method to propagate P. sagittalis in vitro. Low salt concentration (25% of the normal concentration) in the medium promoted greater growth of plantlets because the plants had a higher number of roots and longer roots in such an environment. Our protocol for the micropropagation of P. sagittalis can be accomplished as a two-step procedure within a short period of time (two months) before transplanting
Heterosis for meat quality and fatty acid profiles in crosses among Bos indicus and Bos taurus finished on pasture or grain
Articles in International JournalsPhysicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus× B. indicus bullocks (n=216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefitedwith crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner–Bratzler shear-force in fresh and aged meat was reduced due to heterosis
in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n−6 fatty acids and
PUFA/SFA ratio, and a decline in atherogenic index. The Δ9 desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism
Composição química e de ácidos graxos do músculo longissimus dorsi e da gordura subcutânea de tourinhos Red Norte e Nelore Chemical composition and of fatty acids of the muscle longissimus dorsi and backfat of Red Norte and young Nellore bulls
Objetivou-se com este trabalho avaliar a composição química e o perfil de ácidos graxos do músculo longissimus dorsi e da gordura subcutânea de tourinhos Red Norte e Nelore terminados em confinamento. Utilizaram-se 44 animais, sendo 22 Red Norte com peso vivo inicial médio de 367±30 kg e 22 do grupo Nelore com peso vivo inicial médio de 361±30 kg. Os animais receberam ração à vontade durante 112 dias e foram abatidos com 519 e 482 kg, respectivamente. Amostras do músculo longissimus dorsi e da gordura subcutânea foram coletadas 24 horas após abate entre a 12ª e 13ª costelas para análise da composição centesimal e do perfil de ácidos graxos. As análises de ácidos graxos foram realizadas por meio de cromatografia gasosa, em coluna capilar de 100 m. Não houve diferença na composição química da carne entre os grupos genéticos. Nos animais Red Norte, foram maiores os teores dos ácidos graxos pentadecanoico, palmítico, palmitoleico, linoleico e ácido linoleico conjugado (CLA), enquanto nos animais Nelore foi encontrado o maior teor de ácido oleico. O músculo longissimus dorsi apresentou maiores teores dos ácidos láurico, heptadecenoico, esteárico, linoleico, α-linolênico e araquidônico. Em comparação ao músculo longissimus dorsi, na gordura subcutânea foram maiores os teores dos ácidos mirístico, miristoleico, pentadecanoico, palmítico, palmitoleico, oleico e CLA. Os animais Red Norte apresentaram maiores teores de ácidos graxos saturados em comparação aos Nelore. Em bovinos, o perfil de ácidos graxos depositados no músculo é diferente do observado na gordura subcutânea. O perfil de ácidos graxos da carne de tourinhos difere entre grupos genéticos.<br>The objective of this study was to evaluate the chemical composition and the fatty acid profile of the longissimus dorsi muscle and the backfat thickness of Red Norte and Nellore young bulls finished in feedlot. Fourty-four animals (22 Red Norte with initial average weight of 367±30 kg and 22 Nellore at initial average weight of 361±30 kg) were used. The animals were fed ad libitum during 112 days, slaughtered at 519 and 482 kg, respectively. Samples of the longissimus dorsi muscle and backfat thickness were collected 24 hours after slaughter between the 12th and 13th ribs for analysis of the chemical composition and the fatty acids profile. Fatty acid analyses were performed by gas chromatography with a 100-m capillary column. There was no difference for the chemical composition of the meat between the genetic groups. Red Norte animals showed higher contents of pentadecanoic, palmitic, palmitoleic, linoleic and conjugated linoleic acid (CLA) fatty acids, while Nellore animals had the highest content of oleic acid. The muscle longissimus dorsi showed greater concentrations of lauric, heptadecenoic, stearic, linoleic, α-linoleic and arachidonic acids. Comparing the fatty acid deposited in the longissimus dorsi muscle with backfat thickness, the latter showed higher contents of miristic, miristoleic, pentadecanoic, palmitic, palmitoleic, oleic and CLA acids. Red Norte animals showed higher contents of saturated fatty acid than Nellore. In bovine, the profile of fatty acids deposited in the muscle is different than the that in the backfat thickness. The fatty acids profile of the meat from young bulls differs between genetic groups