994 resultados para seed vigor


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pós-graduação em Ciências Biológicas (Zoologia) - IBRC

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Oils extracted from Cucurbitaceae seeds were characterised for their fatty acid and tocopherol compositions. In addition, some physicochemical characteristics, total phenolic contents and the radical-scavenging activities were determined. Oil content amounted to 23.9% and 27.1% in melon and watermelon seeds, respectively. Physicochemical characteristics were similar to those of other edible oils and the oils showed significant antioxidant activities. Fatty acid composition showed total unsaturated fatty acid content of 85.2–83.5%, with linoleic acid being the dominant fatty acid (62.4–72.5%), followed by oleic acid (10.8–22.7%) and palmitic acid (9.2–9.8%). The oils, especially watermelon seed oil, showed high total tocopherol and phenolic contents. The γ-tocopherol was the predominant tocopherol in both oils representing 90.9 and 95.6% of the total tocopherols in melon and watermelon seed oils, respectively. The potential utilisation of melon and watermelon seed oils as a raw material for food, chemical and pharmaceutical industries appears to be favourable.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Seed dispersal effectiveness (SDE) is a conceptual framework that aims at quantifying the contribution of seed dispersal vectors to plant fitness. While it is well recognized that diplochorous dispersal systems, characterized by two successive dispersal steps performed by two different vectors (Phase I=primary seed dispersal and Phase II=secondary seed dispersal) which are common in temperate and tropical regions, little attention has been given to distinguishing the relative contribution of one-phase and two-phase dispersal to overall SDE. This conceptual gap probably results from the lack of a clear methodology to include Phase II dispersal into the calculation of SDE and to quantify its relative contribution. We propose a method to evaluate the relative contribution of one-phase and two-phase dispersal to SDE and determine whether two seed dispersers are better than one. To do so, we used the SDE landscape and an extension of the SDE landscape, the Phase II effect landscape, which measures the direction and magnitude of the Phase II dispersal effect on overall SDE. We used simulated and empirical data from a diplochorous dispersal system in the Peruvian Amazon to illustrate this new approach. Our approach provides the relative contribution of one-phase SDE (SDE1) and two-phase SDE (SDE2) to overall SDE and quantifies how much SDE changes with the addition of Phase II dispersal. Considering that the seed dispersal process is context dependent so that Phase II depends on Phase I, we predict the possible range of variation of SDE according to the variation of the probability of Phase II dispersal. In our specific study system composed of two primate species as primary dispersal vectors and different species of dung beetles as secondary dispersal vectors, the relative contribution of SDE1 and SDE2 to overall SDE varied between plant species. We discuss the context dependency of the Phase II dispersal and the potential applications of our approach. This extension to the conceptual framework of SDE enables quantitative evaluation of the effect of Phase II dispersal on plant fitness and can be easily adapted to other biotic and/or abiotic diplochorous dispersal systems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to adapt the methodology of the accelerated aging and electrical conductivity tests for determination of physiological potential in crambe seeds. Six seed lots of crambe (cv. FMS Brilhante) were subjected to determination of moisture content, germination test, first count germination, emergence, and emergence speed index. For the accelerated aging test, the traditional methodology was used with water, and with a saturated potassium chloride and sodium chloride solution in three periods of exposure (24, 48, and 72 hours) at 41 degrees C; the electrical conductivity test was performed with four pre-soaking treatments (0, 2, 4, and 8 hours) and four soaking periods (4, 8, 16, and 24 hours) at 25 degrees C. The accelerated aging test with water for 72 hours and the electrical conductivity test with 2 hours of pre-soaking and assessment after 16 hours were effective for classification of the crambe seed lots in regard to physiological quality.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper aims to shed light on a current and important theme that has been gaining increasing importance for governments, society and companies: the greening of agricultural companies in developing countries. The research objective is to classify a Brazilian cotton seed processing company in the evolutionary stages of environmental management: reactive, preventive or proactive. Design/methodology/approach– A case study was conducted in a Brazilian cotton seed processing company.Findings– The main results are: the studied company is positioned in the preventive stage of environmental management; this company is investing in operational green practices; environmental management in this company is motivated by various factors aiming at an increased competitive advantage. Finally, it can be concluded that this company is looking for green opportunities towards the proactive environmental management stage.