Differential seed germination of a keystone palm (Euterpe edulis) dispersed by avian frugivores

The effectiveness of seed dispersal by vertebrates has been analysed by examining both quantitative and qualitative components (Jordano & Schupp 2000, Schupp et al. 2010). While the quantitative component is relatively easily assessed in the field (e.g. visitation rate, number of fruits eaten per visit), the qualitative component (e.g. fate of dispersed seeds, seed treatment in the digestive system of the disperser) is rarely studied under natural conditions, because it is difficult to measure the effects on seeds once ingested by the dispersers (Cortes et al. 2009). © Cambridge University Press 2012.

Frugivory and Seed Dispersal by Northern Pigtailed Macaques (Macaca leonina), in Thailand

Tropical rain forest conservation requires a good understanding of plant-animal interactions. Seed dispersal provides a means for plant seeds to escape competition and density-dependent seed predators and pathogens and to colonize new habitats. This makes the role and effectiveness of frugivorous species in the seed dispersal process an important topic. Northern pigtailed macaques (Macaca leonina) may be effective seed dispersers because they have a diverse diet and process seeds in several ways (swallowing, spitting out, or dropping them). To investigate the seed dispersal effectiveness of a habituated group of pigtailed macaques in Khao Yai National Park, Thailand, we examined seed dispersal quantity (number of fruit species eaten, proportion in the diet, number of feces containing seeds, and number of seeds processed) and quality (processing methods used, seed viability and germination success, habitat type and distance from parent tree for the deposited seeds, and dispersal patterns) via focal and scan sampling, seed collection, and germination tests. We found thousands of seeds per feces, including seeds up to 58 mm in length and from 88 fruit species. Importantly, the macaques dispersed seeds from primary to secondary forests, via swallowing, spitting, and dropping. Of 21 species, the effect of swallowing and spitting was positive for two species (i. e., processed seeds had a higher % germination and % viability than control seeds), neutral for 13 species (no difference in % germination or viability), and negative (processed seeds had lower % germination and viability) for five species. For the final species, the effect was neutral for spat-out seeds but negative for swallowed seeds. We conclude that macaques are effective seed dispersers in both quantitative and qualitative terms and that they are of potential importance for tropical rain forest regeneration. © 2013 Springer Science+Business Media New York.

Effect of seed addition on SnO2-based varistors for low voltage application

The effect of seed addition on the microstructure and non-ohmic properties of the SnO2 + 1%CoO + 0.05%Nb2O5 ceramic-based system was analyzed. Two classes of seeds were prepared: 99% SnO2 + 1%CuO and 99% SnO2 + 1%CoO (mol%); both classes were added to the ceramic-based system in the amount of 1%, 5%, and 10%. The two systems containing 1% of seeds resulted in a larger grain size and a lower breakdown voltage. The addition of 1% copper seeds produces a breakdown voltage (V b) of ∼ 37 V and a leakage current (fic) of 29 μA. On the other hand, the addition of 1% cobalt seeds produced a breakdown voltage of 57 V and a leakage current of 70 μA. Both systems are of great technological interest for low voltage varistor applications, by means of appropriate strategies to reduce the leakage current. Using larger amounts of seeds was not effective since the values of breakdown voltage in both cases are close to a system without seeds. To our knowledge, there are no reports in the literature regarding the use of seeds in the SnO2 system for low voltage applications. A potential barrier model which illustrates the formation of oxygen species (O′2(ads), O′ads, and O″ads) at the expense of clusters near the interface between grains is proposed. © 2012 The American Ceramic Society.

Functional Redundancy and Complementarities of Seed Dispersal by the Last Neotropical Megafrugivores

Background: Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest. Methodology/Principal Findings: We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest. Conclusions/Significance: Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers. © 2013 Bueno et al.

Hepatoencephalopathy syndrome due to Cassia occidentalis (Leguminosae, Caesalpinioideae) seed ingestion in horses

Cassia occidentalis is a bush from the Leguminosae family, subfamily Caesalpinoideae, and is a toxic plant of veterinary interest due to the occasional contamination of animal rations. This report describes the clinical and histopathological findings of an outbreak of C.occidentalis poisoning in horses. Twenty mares were poisoned after consuming ground corn contaminated with 8% of C.occidentalis seeds. Of the 20 animals affected, 12 died: 8 mares were found dead, 2 died 6h after the onset of clinical signs compatible with hepatic encephalopathy and the 2 other animals were subjected to euthanasia 12h after the onset of the clinical signs. The remaining 8 mares presented with mild depression and decreased appetite, but improved with treatment and no clinical sequelae were observed. In 6 animals that underwent a necropsy, an enhanced hepatic lobular pattern was noted and within the large intestine, a large number of seeds were consistently observed. Hepatocellular pericentrolobular necrosis and cerebral oedema were the main histological findings. In one mare, there was mild multifocal semimembranosus rhabdomyocytic necrosis and haemorrhage. Seeds collected from intestinal contents and sifted from the culpable feedstuff were planted. Examination of the leaves, flowers, fruits and seeds of the resultant plants identified C.occidentalis. Horses poisoned by C.occidentalis seeds demonstrate clinical signs associated with hepatoencephalopathy and frequently die suddenly. Lesions primarily involve the liver and secondarily, the central nervous system. Cassia occidentalis poisoning should be considered a differential diagnosis in horses with hepatoencephalopathy and special caution should be taken with horse rations to avoid contamination with seeds of this toxic plant. © 2012 EVJ Ltd.

Inoculação de sementes com bactéria diazotrófica e aplicação de nitrogênio em cobertura e foliar em milho

Considering the importance of nitrogen management and its biological fixation with diazotrophic bacteria, this study was carried out aiming to evaluate the agronomic performance of maize, in response to seed inoculation with Azospirillum brasilense and nitrogen application in side-dressing and leaf. The experiment was conducted in Selvíria, Mato Grosso of Sul State, Brazil, during the growing season 2010/2011, on a clayey Rhodic Haplustox (20° 20' S and 51° 24' W, with altitude of 340 m). Sixteen treatments were established with four replications, in randomized blocks with the combination of the factors A. brasilense (with and without inoculante), nitrogen rate (0 and 90 kg ha-1, in V5 growth stage) and urea leaf application (0, 4, 8 and 12%: application in V5 and V8 growth stage). The maize hybrid used was the DKB 390 YG®, sowed in the row spacing of 0.9 m. Parameters measured were productive and morphological components of culture and crop yield. Increase in maize yield by seed inoculation with A. brasilense was observed. The application of 90 kg ha -1 of nitrogen in side-dressing provided higher chlorophyll leaf index, stalk diameter and prolificacy, however, the yield not was increased. The application of urea leaf did not agronomic efficiency and, therefore, should not be used as the unique form of supply and alternative to nitrogen addition to crop.

Structural changes in soybean seed coat due to harvest time and storage

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

Use of conventional electrochemical techniques to produce crystalline FeRh alloys induced by Ag seed layer

By combining galvanic displacement and electrodeposition techniques, an ordered Fe20Rh80 structure deposited onto brass was investigated by X-ray diffractometry, Mössbauer spectroscopy and magnetization measurements. Mössbauer and X-ray diffraction analyses suggest that the Fe-Rh alloy directly electrodeposited onto brass displays a nanocrystalline state while a similar alloy deposited onto Ag/brass shows a faced centered cubic-like structure, with dendrites-like features. These results directly indicate that the presence of Ag seed layer is responsible for the Fe-Rh alloy crystallization process. In addition, room temperature Mössbauer data indicate firstly paramagnetic states for two Fe-species. In the dominant Fe-species (major fraction of the Mössbauer spectra), Fe atoms are situated at a cubic environment and it can be attributed to the γ-Fe20Rh80 alloy based on their hyperfine parameters. In the second species, Fe atoms are placed in a non-local symmetry, which can be related to Fe atoms at the grain boundaries or/and Fe small clusters. These Fe-clusters are in superparamagnetic state at room temperature, but they may be ordered below 45 K, as suggested by magnetization data. © 2013 Elsevier B.V. All rights reserved.

Functional extinction of birds drives rapid evolutionary changes in seed size

Local extinctions have cascading effects on ecosystem functions, yet little is known about the potential for the rapid evolutionary change of species in human-modified scenarios. We show that the functional extinction of large-gape seed dispersers in the Brazilian Atlantic forest is associated with the consistent reduction of the seed size of a keystone palm species. Among 22 palm populations, areas deprived of large avian frugivores for several decades present smaller seeds than nondefaunated forests, with negative consequences for palm regeneration. Coalescence and phenotypic selection models indicate that seed size reduction most likely occurred within the past 100 years, associated with human-driven fragmentation. The fast-paced defaunation of large vertebrates is most likely causing unprecedented changes in the evolutionary trajectories and community composition of tropical forests.

Specialized Seed Dispersal in Epiphytic Cacti and Convergence with Mistletoes

Mistletoes represent the best example of specialization in seed dispersal, with a reduced assemblage of dispersal agents. Specific dispersal requirements mediated by the specificity of seed deposition site have apparently led to the evolution of such close relationships between mistletoes and certain frugivores. Here, we provide evidences for another case of specialization involving epiphytic cacti in the genus Rhipsalis, and small Neotropical passerines Euphonia spp., which also act as the main seed dispersers of mistletoes in the family Viscaceae. With field observations, literature search, and observations on captive birds, we demonstrated that Rhipsalis have specific establishment requirements, and euphonias are the most effective dispersers of Rhipsalis seeds in both quantitative and qualitative aspects, potentially depositing seeds onto branches of host plants. We interpret the similar dispersal systems of Rhipsalis and Viscaceae mistletoes, which involve the same dispersal agents, similar fruit morphologies, and fruit chemistry as convergent adaptive strategies that enable seeds of both groups to reach adequate microsites for establishment in host branches. © 2013 by The Association for Tropical Biology and Conservation.

Inclusão de grãos de girassol na ração de cordeiros sobre as características quantitativas da carcaça e qualitativas da carne

This study aimed to evaluate the carcass quantitative characteristics, tissue composition of carcass cuts and meat quality of lambs receiving sunflower seeds in the diet. Twenty-one lambs 7/8 Ile de France 1/8 Ideal, not castrated, with initial body weight of 17 kg were housed in individual pens and distributed in three diets (0,7.5 and 15% of sunflower seeds inclusion) in a completely randomized design in 3 x 2 factorial arrangement (three diets and two carcass cuts). At the end of the experimental period, the animals were slaughtered; weights and hot and cold carcass yields and commercial and biological carcass dressing were collected. The carcasses were split lengthways and left half carcass divided into six anatomical parts. The leg and loin were removed for evaluation of tissue composition, meat color, water holding capacity, cooking losses and shearing force. Difference was detected in the commercial carcass yield; with higher value (46.82% of total weight) for carcasses of lambs fed without sunflower seeds when compared with carcass yield (44.11%) of lambs fed with 15% of sunflower seed inclusion. The proportion of muscle and total fat, as muscle:fat ratio were affected (P<0.05) by feeding, with higher quantity of muscle (63.15%) and less fat (16.63%) in the leg and loin cuts of lambs fed without sunflower seeds. In the leg was observed higher proportions of muscle (67.27%), muscle:bone ratio (4.08) and muscle:fat ratio (4.92) when compared with the loin cut. The water retention capacity and shearing force of Longissimus lumborum muscle showed better results when compared with Semimembranosus muscle. The inclusion of sunflower seeds in the diet of feedlot lambs increased the fat deposition in carcass cuts, however did not affect the other parameters of meat quality.

Physico-chemical characterization of seed oils extracted from oranges (Citrus sinensis)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seed germination of two Syagrus species native to Brazil

Palm species native to Brazil such as Syagrus picrophylla and S. schizophylla have great ornamental value and for this reason are much demanded for use in landscape. Its propagation is by seeds and often presents considerable problems to nursery managers because their seed has a hard and impermeable shell. Temperature is one of the factors that influence the seed germination process; however, the information for these species is scarce. Thus, this work aimed to study the effects of temperature regimes on the germination of S. picrophylla and S. schizophylla seeds and develop some recommendations in which temperature will obtain high rates of seed germination. The experimental design was entirely randomized with six temperatures and four replications of 25 seeds for each species. Germination and germination rate were evaluated. Higher and faster germination of S. picrophylla and S. schizophylla seeds were verified at constant temperature of 30°C and 35°C; and alternated temperature at 25-35°C.

Effect of temperature on seed germination of ornamental herbaceous perennials

Antirrhinum majus L. and Senecio douglasii DC. are herbaceous perennial ornamental plants used in landscaping. The multiplication of these plants is by seed; however, there are still doubts about the temperature that can provide higher rates and speed of germination. Thus the aim was to study the effect of temperature on seed germination of A. majus and S. douglasii. The study was conducted separately for each species. The experimental design was entirely randomized with six temperature conditions (temperature controlled constant of 20, 25, 30, 35°C and alternating temperatures of 20-30 and 25-35°C with a photoperiod of 12 hours) with four replications of 100 seeds each. Total germination percentage and germination rate were determined. The means were compared by Tukey test at 5%. For A majus the highest germination percentage was observed at 20°C that did not differ statistically from other temperatures. The highest germination rate was obtained at the temperature of 20 and 25°C. For S. douglasii seeds it was observed that the highest germination percentage and germination rate occurred at 20°C. The lower temperature showed the better percentage and germination rate for these species.

Eco-physiological aspects of melaleuca seed germination

The invasive behavior of melaleuca (Melaleuca quinquenervia) plants in wetlands is due to its aggressive regeneration strategy, which is based on its seeds germination performance. Understanding of the eco-physiological aspects of the seed germination in melaleuca plants may significantly contribute for the development of management strategies. The objective of this research was to learn how the germination of M. quinquenervia seeds are affected by light and temperature. Melaleuca seeds were placed on filter paper moistened with 12 ml of distilled water at temperatures between 10 and 45°C. Germination was evaluated in dark and light conditions. Seed germination, first count of seed germination (seven days), germination speed index and germination mean time were determined up to 40 days after seeding, when germination had ceased in most of the treatments. After that period, the seeds were transferred to conditions of 30°C and light, which was found to be ideal in the previous phase. Seed germination was daily evaluated up to 63 days when it was again observed no longer to occur. The treatment repetitions were distributed in the growth-chamber according to a completely randomized design in a factorial scheme (eight temperatures x two light conditions) and four repetitions. The data were submitted to analysis of variance with the F test and the means were adjusted to polynomial and non linear regression models. The highest seed germination performance was observed to take place under conditions of 27.3°C with light. The temperatures of 35 and 40°C in the dark induced thermal inhibition of seed germination. The temperature of 45°C was lethal to the seeds.