New bioactive metabolites produced by Phomopsis cassiae, an endophytic fungus in Cassia spectabilis

Two new metabolites, ethyl 2,4-dihydroxy-5,6-dimethylbenzoate (1) and phomopsilactone (2) were isolated from Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures were elucidated by 1D and 2D NMR, MS and IR spectral data. Compounds 1 and 2 displayed strong antifungal activity against the phytopatogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as cytotoxicity against human cervical tumor cell line (HeLa), in in vitro assays. ©2005 Sociedade Brasileira de Química.

Thelytokous parthenogenesis in the fungus-gardening ant Mycocepurus smithii (Hymenoptera: Formicidae)

The general prevalence of sexual reproduction over asexual reproduction among organisms testifies to the evolutionary benefits of recombination, such as accelerated adaptation to changing environments and elimination of deleterious mutations. Documented instances of asexual reproduction in groups otherwise dominated by sexual reproduction challenge evolutionary biologists to understand the special circumstances that might confer an advantage to asexual reproductive strategies. Here we report one such instance of asexual reproduction in the ants. We present evidence for obligate thelytoky in the asexual fungus-gardening ant, Mycocepurus smithii, in which queens produce female offspring from unfertilized eggs, workers are sterile, and males appear to be completely absent. Obligate thelytoky is implicated by reproductive physiology of queens, lack of males, absence of mating behavior, and natural history observations. An obligate thelytoky hypothesis is further supported by the absence of evidence indicating sexual reproduction or genetic recombination across the species' extensive distribution range (Mexico-Argentina). Potential conflicting evidence for sexual reproduction in this species derives from three Mycocepurus males reported in the literature, previously regarded as possible males of M. smithii. However, we show here that these specimens represent males of the congeneric species M. obsoletus, and not males of M. smithii. Mycocepurus smithii is unique among ants and among eusocial Hymenoptera, in that males seem to be completely absent and only queens (and not workers) produce diploid offspring via thelytoky. Because colonies consisting only of females can be propagated consecutively in the laboratory, M. smithii could be an adequate study organism a) to test hypotheses of the population-genetic advantages and disadvantages of asexual reproduction in a social organism and b) inform kin conflict theory. For a Portuguese translation of the abstract, please see Abstract S1. © 2009 Rabeling et al.

Dry matter yield and nutritional value of Marandu grass under nitrogen fertilization and irrigation in cerrado in São Paulo

The aim of this study was to evaluate dry matter yield and nutritional value of palisade grass (Brachiaria brizantha cv. Marandu) using nitrogen doses and sprinkler irrigation in two periods of the year, aiming at reducing seasonality of forage production. It was used a randomized block design in a split-plot scheme, with five doses of nitrogen (0, 50, 100, 150, and 200 kg/ha/cut), and the sub-plots were defined by the seasons of the year (wet and dry season), with and without irrigation. During the wet season, in the plots with and without irrigation, doses of 175 and 161 kg/ha/cut promoted the highest dry matter yields. During the dry season, 171 kg ha -1N with irrigation resulted in the highest dry matter yield. During the same season, there was no response to N fertilization in the lack of irrigation. Average contents of CP were 10% with and without irrigation. Contents of neutral detergent fiber decreased with nitrogen doses, while acid detergent fiber was not affected by fertilization. Plots under irrigation reached the maximal acid detergent fiber content at N dose of 60 kg ha -1. Irrigation promotes increase of 15% increase in dry matter yield and it increases contents of neutral detergent fiber. © 2010 Sociedade Brasileira de Zootecnia.

Homologies of the flower and inflorescence in the early-divergent grass anomochloa (poaceae)

Premise of the study: The grass subfamily Anomochlooideae is phylogenetically significant as the sister group to all other grasses. Thus, comparison of their structure with that of other grasses could provide clues to the evolutionary origin of these characters. Methods: We describe the structure, embryology, and development of the flower and partial inflorescence of the monotypic Brazilian grass Anomochloa marantoidea. We compare these features with those of other early-divergent grasses such as Pharus and Streptochaeta and closely related Poales such as Ecdeiocolea. Key results: Anomochloa possesses several features that are characteristic of Poaceae, notably a scutellum, a solid style, reduced stamen number, and an ovary with a single ovule that develops into a single indehiscent fruit. Interpretation of floral patterning in Anomochloa is problematic because the ramification pattern of the florets places the bracts and axes in unusual positions relative to the primary inflorescence axis. Our study indicates that there is a single abaxial carpel in Anomochloa, probably due to a cryptic type of pseudomonomery in Anomochloa that resembles the pseudomonomery of other grasses. On the other hand, the Anomochloa flower differs from the typical grass flower in lacking lodicules and possessing four stamens, in contrast with the tristaminate condition that characterizes many other grasses. Conclusions: Using the median part of the innermost bract as a locator, we tentatively homologize the inner bract of the Anomochloa partial inflorescence with the palea of other grasses. In this interpretation, the pattern of monosymmetry due to stamen suppression differs from that of Ecdeiocolea. © 2012 Botanical Society of America.

Morphological evolution in the graminid clade: Comparative floral anatomy of the grass relatives Flagellariaceae and Joinvilleaceae

New comparative data are presented on the reproductive morphology and anatomy of two genera closely related to grasses, Flagellaria and Joinvillea, in which the flowers are superficially similar, especially in stamen morphology. This investigation demonstrates some anatomical differences between the two genera. For example, both genera depart from the 'typical' condition of tepal vasculature (three-traced outer tepals and one-traced inner tepals): in Flagellaria, each tepal receives a single vascular bundle and, in Joinvillea, each tepal is supplied by three vascular bundles. Joinvillea possesses supernumerary carpel bundles, as also found in the related family Ecdeiocoleaceae, but not in Flagellaria or grasses. In the anther, the tapetum degenerates early in Flagellaria, and is relatively persistent in Joinvillea, in which the pollen grains remain closely associated with the tapetum inside the anther locule, indicating a correlation between peripheral pollen (a feature that is common in grasses) and a persistent tapetum. This study highlights the presence of a pollen-tube transmitting tissue (PTTT) or solid style in the gynoecium of Flagellaria, as also in many Poaceae, but not in Joinvillea or Ecdeiocoleaceae. We speculate that the presence of a PTTT could represent one of the factors that facilitated the subsequent evolution of the intimately connected gynoecia that characterize grasses. © 2012 The Linnean Society of London.

Requisitos nutricionais e reprodução massal de Bipolaris euphorbiae

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Production of a bioherbicide agent in liquid and solid medium and in a biphasic cultivation system

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Initial height of pasture deferred and utilized in winter and tillering dynamics of signal grass during the following spring

Tillering dynamics during regrowth in the spring (September to December 2009) on signal grass (Brachiaria decumbens cv. Basilisk) pastures deferred in the beginning of April 2009 is evaluated. Four pasture heights were evaluated at the beginning of deferment (10, 20, 30 and 40 cm). The experimental design consisted of completely randomized blocks with two replications. Rise in pasture height at the beginning of deferment decreased the appearance rate, increased the mortality rate and reduced the survival rate, the balance between appearance and mortality and the stability index of the tiller population at the beginning of the spring. Pastures deferred at initial height of 30 and 40 cm presented relatively stable tiller appearance rate between the beginning and end of spring. However, these pastures presented greater mortality rate, lower survival rate, lower balance between appearance and mortality and lower stability index of the tiller population at the beginning of spring when compared to rates at the end of spring. Pastures managed with shorter initial heights (10 and 20 cm) provided more tissue renewal in the subsequent growth season after their utilization in the winter.

Production of sheep grazing on nitrogen-fertilized tifton 85 grass in continuous stocking

Biomass and forage volume density and the performance and stocking rate of sheep on pastures with nitrogen-fertilized Tifton 85 and subjected to a continuous stocking system were evaluated. Four doses of nitrogen (0, 100, 200, and 400 kg ha-1 year), arranged in an experimental design with randomized blocks and four replications, were analyzed. Sixteen paddocks and Santa Inês sheep were used as test animals, coupled to crossbreed Santa Inês sheep as regulating animal stocking. Nitrogen-fertilized Tifton 85 pastures increased the amount of forage biomass and volume density which affected stocking rate and weight gain of sheep in continuous grazing. When pastures with Tifton 85 were administered in variable load continuous stocking, with grass kept at 15 cm, nitrogen fertilization up to 400 kg ha-1 year is recommended.

Effect of supplementation frequency on intake, behavior and performance in beef steers grazing Marandu grass

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Long-term endemism of two highly divergent lineages of the amphibian-killing fungus in the Atlantic Forest of Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production and Characterization of a Milk-clotting Protease Produced in Submerged Fermentation by the Thermophilic Fungus Thermomucor indicae-seudaticae N31

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Intercropping soybean and palisade grass for enhanced land use efficiency and revenue in a no till system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitrogen budget in a soil-plant system after brachiaria grass desiccation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)