40 resultados para Seed number
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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.
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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.
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The movement patterns of males, females and juveniles of lekking species often differ due to differences in the commitment to lek activities, which may lead to differences in the spatial distribution and dispersal distances of seeds they eat. By sampling seeds in three lek and non-lek areas of the white-bearded manakin (Manacus manacus), we tested whether this lekking species increased the abundance and species richness of seeds in lek areas and, at a finer scale, in 21 displaying courts within lek areas. Combining data on seed defecation or regurgitation rates by free-ranging individuals, the number of seeds in droppings or regurgitations of mist-netted birds, and the distances travelled by birds equipped with radio-transmitters, we estimated the potential spatial distribution of seeds generated by six resident males and six females or juveniles during the morning peak of lek activity and when lek activity decreased in the afternoon. There was no difference in the species richness (46 and 44 morphospecies, respectively) and abundance of seeds (15.4 ± 7.3 seeds and 14.0 ± 1.1 seeds, respectively) between lek and non-lek areas. Within leks both parameters increased in courts (45 spp., 17.6 ± 14 seeds) compared with non-court sites (22 spp., 1.9 ± 1.8 seeds), likely as a consequence of the longer time spent by resident males in perches in or near display courts. Distances moved by juveniles and females per 60-min period (183 ± 272 m) were greater than resident males (42.6 ± 22.0 m) in the mornings, while the opposite happened in the afternoons (55.2 ± 40.7 m and 157 ± 105 m, respectively). We conclude that the spatial aggregation of seeds in lek areas of M. manacus occurs at the court level, and the spatial distribution of deposited seeds varies with manakin lekking status and the daily period of foraging. © Cambridge University Press 2013.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Crambe is an important biofuel crop and its oil has unique traits such as high erucic acid content which can be used as industrial lubricant, corrosion inhibitor as well as ingredient in synthetic rubber manufacturing. Genetic diversity among 70 progenies of Crambe abyssinica Hochst selected from a population of FMS Brilhante cultivar was quantified by multivariate analysis for traits related to germination, thousand grain weight and oil content. There were significant differences among progenies for all traits studied. Estimation of genetic variance and heritability coefficients showed that the variability found in the progeny is more genetic than environmental which enables genetic gains with selection. Heritability coefficient varied from 68 to 79%, except for oil content and number of dead seedlings. Simple correlation analysis showed that germination and vigor were positively correlated, and thousand grain weight and oil content were not correlated with any of the seed traits. Based on multivariate analysis, the progenies could be grouped into 26 clusters. Clusters 1, 2 and 3 had the highest number of progeny with 7, 8 and 6 lineages, respectively. Clusters 21-26 had higher dissimilarity within the cluster with one in each progeny. The trait that most contributed to the cluster was the germination (36.2%) and less contributed was the number of seedlings killed (1.1%). The progenies indicate genetic diversity for seed traits and the selection of superior progenies is possible considering the studied traits. © 2013.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Ciências Biológicas (Zoologia) - IBRC
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The aim of this study was to evaluate the allelopathic effect of soil samples collected under the canopies of three specimens of Copaifera langsdorffii the germination of Lactuca sativa and survey the natural seed bank according to seasonality. To test the allelopathic effect was carried experiments of pre and post-emergence with seeds of L. sativa and to quantify the stock of seeds, soil samples were collected from three specimens at three distances from the stem (1, 2 and 3 m) and at three depths (0-5, 5-10 and 10-15cm) in the region of savanna in the dry and wet seasons. The samples tested in bioassay of pre-emergence no significant influence on germinability, mean germination time and mean germination speed, but showed a difference in the synchronism of germination, these data were independent of sampling station. In test for post-emergence was observed statistical difference in the parameters evaluate (length of primary roots and hypocotyls) in both seasons. To quantify the natural seed bank were macroscopic analysis of each soil sample with the help of stereoscopic microscope. The analysis of the natural seed bank showed a larger number of seeds in the 0-5cm and in distance of 2m for both seasons. The results suggest the presence of allelochemical substances in soil samples collected under the canopy of Copaifera langsdorffii.
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Aims: This work aimed to assess how seed size, vials, vial sealing (in vitro), and substrate (in vivo) affect C. regium germination and emergence. This study shall contribute to the viable production of C. regium seedlings. Study Design: The experimental design used in these experiments was randomized. Place and Duration of Study: Department of Plant Biotechnology, Universidade de RibeirãoPreto, between March 2010 and December 2010. Methodology: This work has evaluated how seed size, vials, vial sealing (in vitro), and substrate (in vivo) influence the germination and emergence of C. regium. Results: The results showed that cultivation of C. regium seedlings from seeds is viable, irrespective of seed size. Vial oxygenation is an important parameter to consider in vitro, to obtain a larger number of normal seedlings. As for in vivo conditions, germination should be conducted in sand, to ensure a greater amount of young seedlings. Conclusion: The results presented here attested that it is possible to produce C. regium seedlings from seeds of any size both in vivo and in vitro conditions. In vitro, it is important to consider vial oxygenation, in order to obtain a greater amount of normal seedlings. In vivo, germination should be conducted in sand, to ensure production of a large quantity of seedlings.