Interação entre espécies forrageiras nativas e cultivadas em condições de semiárido: revisão / Interaction between native forage species and those cultivated under semi-arid conditions: a review / Interacción entre especies forrajeras nativas y cultivadas en condiciones de semiárido: revisión

O capim-aruana é uma nova opção de gramínea para implantação no semiárido. Ambiente que apresenta ocorrência natural de outras espécies como as espontâneas adaptadas as condições edafoclimáticas da região. É fato reconhecido a importância dessas plantas em meio as pastagens, pelo fato de aumentar a biomassa vegetal, servir de proteção do solo contra a erosão, aumentar a diversidade do pasto oferecendo opção de seletividade para o animal. Foi realizado um levantamento de informações disponíveis na literatura sobre a temática abordada, apresentando informações relevantes para melhor entendimento da temática. A identificação botânica ou citogenética das espécies que estão presentes na pastagem possibilita conhecer se determinada espécie possui potencial forrageiro ou pode causar algum dano à saúde animal como a intoxicação e permite escolher melhor a forma de manejo da área. Assim, conclui-se que o capim-aruana é uma alternativa interessante para ser adotada em sistemas de produção por aliar características adaptativas, agronômicas e nutricionais que visam incrementar a produção pecuária em sistemas de clima semiárido.(AU)

The Guinea grass is a new option for implantation in the Brazilian semi-arid region. That area presents the natural occurrence of other species such as the spontaneous ones already adapted to the edaphoclimatic conditions of the region. The importance of those plants amid the grazing land is recognized since they increase the offer of vegetal biomass, protect the soil against erosion, increase the grazing diversity by offering an option for the animals. A survey was performed seeking literature information on the addressed topic, presenting relevant information for its better understanding. The botanical or cytogenetic identification of the species present in the pasture allows determining if a given species has foraging potential or if it can cause harm to animal health, such as intoxication, and thus, provides better knowledge of choosing the best handling practices for the area. Therefore, it can be concluded that the Guinea grass is an interesting alternative to be adopted in production systems by combining adaptive, agronomic and nutritional characteristics that aim at increasing livestock production in semi-arid climate systems.(AU)

El capim-aruana es una nueva opción de gramínea para implantación en el semiárido. Ambiente que presenta ocurrencia natural de otras especies como las espontáneas adaptadas a las condiciones edáficas y climáticas de la región. Es un hecho reconocido la importancia de esas plantas en medio de los pastos, por el hecho de aumentar la biomasa vegetal, servir de protección del suelo contra la erosión, aumentar la diversidad del pasto ofreciendo opción de selectividad para el animal. Se realizó una investigación de informaciones disponibles en la literatura sobre el tema abordado, presentando informaciones relevantes para una mejor comprensión del tema. La identificación botánica o citogenética de las especies que están presentes en el pastoreo posibilita conocer si determinada especie posee potencial forrajero o puede causar algún daño a la salud animal, como la intoxicación, y permite escoger mejor la forma de manejo del área. Por lo tanto, concluimos que el capim-aruana es una alternativa interesante para ser adoptada en los sistemas de producción por combinar características adaptativas, agronómicas y nutricionales que apuntan a aumentar la producción ganadera en sistemas de clima semiárido.(AU)

Efficiency of water use and nitrogen for goat milk production in irrigated pasture to different management / Eficiência de uso de água e nitrogênio para produção de leite de cabra em pastagem irrigada sob diferentes manejos

The aim was to determine the efficiency of use of water and nitrogen for forage production and goat-milk production on an irrigated Tanzania Guineagrass (Panicum maximum cv. Tanzânia) pasture subjected to different management practices. The management levels tested were combinations among nitrogen fertilization levels and post-grazing residual heights (ResH): Intensive (ResH = 33.0cm and 600.0kg N/ha.year-1); Moderate (ResH = 47.0cm and 300.0kg N/ha.year-1); Light (ResH = 47cm and 0kg N/ha.year-1); and Conventional (ResH = 33cm and 0kg N/ha year-1). The efficiency of water use for forage production was higher in intensive and Moderate management. The Conventional management was recommended only for forage production since there is no nitrogen input available because this result was similar to Intensive management in water efficiency. The efficiency of water use to produce goat milk was higher in Intensive management. Moderate management presented higher efficiency of nitrogen to produce forage. On the other hand, Intensive management was more efficient using nitrogen in goat milk production. The amount of water needed to produce one liter of goat milk varied from 893.20 to 3,933.50L. In the moderate management, up to 121.48kg forage and 21.56kg of milk were produced for every kilogram of N utilized. Intensive management is advantageous for water use efficiency as well nitrogen efficiency to produce goat milk in cultivated pasture.(AU)

Objetivou-se determinar a eficiência de uso de água e nitrogênio para a produção de forragem e de leite de cabra em pasto irrigado de capim-tanzânia, submetido a diferentes manejos. Os manejos testados foram combinações entre níveis de adubação nitrogenada e alturas residuais pós-pastejo (Altr): intensivo (Altr = 33,0cm e 600,0kg N/ha.ano-1); moderado (Altr = 47,0cm e 300,0kg N/ha.ano-1); leve (Altr = 47,0cm e 0kg N/ha.ano-1) e convencional (Altr = 33,0cm e 0kg N/ha.ano-1). A eficiência do uso de água para produção de forragem foi obtida nos manejos intensivo e moderado. O manejo convencional só foi interessante no caso da produção de forragem em situação de ausência de nitrogênio, não diferindo do manejo intensivo para a eficiência de uso de água. A eficiência de uso de água para a produção de leite foi maior no intensivo. A maior eficiência do uso de nitrogênio para produzir forragem foi no moderado, enquanto a maior eficiência de nitrogênio para a produção de leite foi no intensivo. A quantidade de água para produzir um litro de leite de cabra variou de 893,20 em manejo intensivo a 3.933,50L em convencional. Manejo intensivo é vantajoso para eficiência de uso de água e nitrogênio para a produção de forragem e de leite de cabra.(AU)

Establishment of Efficient System for Isolation and Manipulation of Single Protoplasts Containing Aposporous Embryo Sac Initial Cell in Guinea Grass (Panicum maximum).

Aims: In order to do the molecular analysis of mechanism of aposporous embryo sac initial cell (AIC) appearance, as the first step, we attempted to establish the system of isolating and manipulating single cells containing AIC using different methods in guinea grass (Panicum maximum). Study Design: At first, single protoplasts were isolated from the ovaries staged in different developmental stages using different pre-treatments and different concentrations of enzyme solutions on ovaries; Based on it, the single protoplasts containing AIC were manipulated with ultra particle electronic syringe picopipet (UPESP) machine set onto microscope. Place and Duration of Study: Faculty of Environmental and Horticultural Science, Minami Kyushu University, between June 2012 and December 2013. Methodology: The ovary of facultatively apomictic guinea grass (Panicum maximum) was used as materials in this study for single protoplast isolation. The ovaries were classified and collected from young buds and flowers staged in different developmental stages, according to the colors of stigma and the ovary length. And then, the ovaries were pre-treated with needle into different shapes, and treated with different kinds of enzyme solution with different concentrations of mannitol to increase efficiency of protoplast isolation. In final, the single protoplasts containing AIC isolated from different stages of ovaries were manipulated by handle control. Results: 1) The ovaries in different stages of before AIC appearance, AIC appearance, and AIC-derived embryo sac formation were collected successfully and respectively, indicating that the stigma colors and length of ovaries are proportionate to stages of ovary mature. And single protoplasts containing AIC were isolated from the ovaries staged in white to yellow color. 2) The ovaries be flooded in enzyme solution, were pre-treated with needle in 4 types, that is, (1) Cut in micropylar end; (2) Cut in chalazal end; (3) Cut in middle part; (4) after 1hr of (3) treatment, cut in micropylar end. As a result, the efficiency of protoplast isolation of (3) and (4) was 1-2 hrs shorter than that of (1) and (2). 12%, 11%, 10% and 9% were proper enzyme concentrations for obtaining perfect shingle protoplasts from the ovaries with white, yellow, peach and purple colors, respectively. 3) The single protoplasts containing AIC were collected and manipulated with UPESP in the performance of controlled aspiration and spit. Conclusion: In this study, in order to do molecular analysis of the mechanism of AIC appearance, we focus on that, the key points were to isolate AIC single protoplasts from apomictic guinea grass using different methods, and then to establish the method of controlling a single protoplast using UPESP machine. These results obtained in this study will be a useful tool for molecular analysis of AIC, and provide important information for clarification of apomixis reproductive mode.