Morphological effects of neem (Azadirachta indica A. Juss) seed oil with known azadirachtin concentrations on the oocytes of semi-engorged Rhipicephalus sanguineus ticks (Acari: Ixodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Development of ovule, fruit and seed of Xyris (Xyridaceae, Poales) and taxonomic considerations

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Partitioning the relative contribution of one-phase and two-phase seed dispersal when evaluating seed dispersal effectiveness

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.

Seed quality, chlorophyll content index and leaf nitrogen levels in maize inoculated with Azospirillum brasilense

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Community-wide spatial and temporal discordances of seed-seedling shadows in a tropical rainforest

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

Supplementation with sunflower seed increases circulating cholesterol concentrations and potentially impacts on the pregnancy rates in Bos indicus beef cattle

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

Greening a Brazilian cotton seed processing company: from challenges to strategic opportunities

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.

Phenolic compounds influence seed dormancy of palicourea rigida h.b.k. (rubiaceae), a medicinal plant of the brazilian savannah

Palicourea rigida H.B.K. (Rubiaceae), a medicinal species commonly known as douradinha, has wide distribution across ecosystems in Central and South America. This species exhibits seed dormancy delaying germination until optimal conditions for seedling growth and development are in place. While dormancy ensures species survival, it also presents a technical problem for developing P. rigida’s plant production program. Thus, the objective of this study was to investigate if secondary metabolites present in seeds influence the seed dormancy of P. rigida. Mature fruits were harvested from the native habitat, in the savanna region of the State of Minas Gerais during February 2009, 2010 and 2011. The content of phenolic compounds in the seed of P. rigida was measured, and the allelopathic effects were assessed using the germination of lettuces as model to detect phytotoxicity. The P. rigida seeds geminated at rates varying between 7% and 31% with a Seed Germination Index (SGI) of 0.09. Data suggest that the phenolic compounds present in the seeds may be responsible for seed dormancy.

Germination of Cochlospermum regium Seeds: Influence of Seed Size, Vials, Vial Sealing In vitro, and Substrate In vivo

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.