Influence of organic and mineral soil fertilization on essential oil of Spilanthes oleracea cv. Jambuarana

In the present study, the composition of essential oil of leaves and inflorescences of jambu (Spilanthes oleracea. Jambuarana), under organic manuring and mineral fertilization, was stuhed. Jambu plants show important chemical properties and their production has been addressed for the extraction of the essential oils for cosmetics industries, due to their pharmacolopcal properties. The experimental area of treatments contained urea as mineral fertilizer (120 g m2), applied twice and organic fertilizer (8 kg m2), applied at the planting. Jambu leaves and flowers were harvested twice: the first at 90 days after seedling transplantation and at the opening of the flower buds. Branches were cut at 7 cm from the soil, thus new branches can bud for the accomplishment of the second crop which happened 40 days after the re-budhng. The essential oil was analyzed by gas chromatography coupled with mass-spectrometry. According to our results the most representative compounds were trans-caryophyllene, germacrene-D, 1-dodecene, spathulenol and spilanthol (a compound presenting anesthetic properties) occurring in inflorescences. Fertilization procedure does not affect the content and the quality of the essential oil in Jambu plants. © 2012 Academic Journals Inc.

Controle da mancha angular do feijoeiro com uso de fungicidas e seu efeito na produção das plantas

The angular leaf spot of dry bean caused by the fungus Phaeoisairopsis griseola is a very important disease on dry bean crops in Brazil. In propitious weather conditions, susceptible cultivars have significant losses due to this disease. In these conditions, fungicide usage is an important step for angular leaf spot management. Since the effects of this method of control on plant physiology are not known, this study had the following objectives: a) Verify the action of fungicide in physiological changes in dry beans (photosynthesis rate and stomatal conductivity); b) evaluate the efficacy of some fungicides for the control of angular leaf spot; and c) examine the effects of these fungicides on other agronomic parameters; weight of 100 grains, number of grains per pod and number of pods per plant. The dry bean cultivar used in this study was Perola. Four trials were conducted, two in a net greenhouse and two trials under field conditions. A spray of piraclostrobin, tebuconazol and tebuconazol+ trifloxistrobin increased photosynthesis rates, although stomatal conductivity was not changed. In addition, sprays of tebuconazol, piraclostrobin, metiram+piraclostrobin and azoxistrobin provided better levels of disease control and also higher weight of 100 grains, with the exception of azoxystrobin for this parameter.

Unbiased approach to diagnose the nutrient status of red guava (Psidium guajava)

Fertilization of guava relies on soil and tissue testing. The interpretation of tissue test is currently conducted by comparing nutrient concentrations or dual ratios with critical values or ranges. The critical value approach is affected by nutrient interactions. Nutrient interactions can be described by dual ratios where two nutrients are compressed into a single expression or a ternary diagrams where one redundant proportion can be computed by difference between 100% and the sum of the other two. There are D(D-1) possible dual ratios in a D-parts composition and most of them are thus redundant. Nutrients are components of a mixture that convey relative, not absolute information on the composition. There are D-1 balances between components or ingredients in any mixture. Compositional data are intrinsically redundant, scale dependent and non-normally distributed. Based on the principles of equilibrium and orthogonality, the nutrient balance concept projects D-1 isometric log ratio (ilr) coordinates into the Euclidean space. The D-1 balances between groups of nutrients are ordered to reflect knowledge in plant physiology, soil fertility and crop management. Our objective was to evaluate the ilr approach using nutrient data from a guava orchard survey and fertilizer trials across the state of São Paulo, Brazil. Cationic balances varied widely between orchards. We found that the Redfield N/P ratio of 13 was critical for high guava yield. We present guava yield maps in ternary diagrams. Although the ratio between nutrients changing in the same direction with time is often assumed to be stationary, most guava nutrient balances and dual ratios were found to be non-stationary. The ilr model provided an unbiased nutrient diagnosis of guava. © ISHS.

Ecological and evolutionary consequences of living in a defaunated world

Defaunation, the loss or population decline of medium and large native vertebrates represents a significant threat to the biodiversity of tropical ecosystems. Here we review the anthropogenic drivers of defaunation, provide a brief historical account of the development of this field, and analyze the types of biological consequences of this impact on the structure and functioning of tropical ecosystems. We identify how defaunation, operating at a variety of scales, from the plot to the global level, affects biological systems along a gradient of processes ranging from plant physiology (vegetative and reproductive performance) and animal behavior (movement, foraging and dietary patterns) in the immediate term; to plant population and community dynamics and structure leading to disruptions of ecosystem functioning (and thus degrading environmental services) in the short to medium term; to evolutionary changes (phenotypic changes and population genetic structure) in the long-term. We present such a synthesis as a preamble to a series of papers that provide a compilation of our current understanding of the impact and consequences of tropical defaunation. We close by identifying some of the most urgent needs and perspectives that warrant further study to improve our understanding of this field, as we confront the challenges of living in a defaunated world. © 2013 Elsevier Ltd.

Chemical control of pathogens and the physiological performance of peanut seeds

The establishment of a peanut crop may be unsatisfactory due to poor seed performance in the field and among the factors attributed to this are a reduction in seed vigor during storage and the presence of pathogens. The objective of this study was to evaluate the efficiency of treating peanut seeds with fungicides and the effect on physiological performance and disease control during storage. In a completely random experimental design, two seed batches of the Runner IAC 886 peanut cultivar were submitted to five fungicide treatments (1 control - untreated; 2 thiram; 3 carbendazim + thiram; 4 fludioxonil + metalaxyl-m; 5 fludioxonil + mefenoxam + thiabendazole) and evaluated after zero, 30 and 60 days of storage. The seeds were stored untreated but treated before the evaluation of physiological performance from germination, vigor (first germination count and accelerated aging), field seedling emergence and seed sanitation tests. The results showed differences in batch performance potential during storage, with batch 1 being superior. The sanitation test showed that all the chemical seed treatments controlled pathogens efficiently (Aspergillus spp. and Penicillium sp.), but only thiram did not affect peanut seed performance in the laboratory evaluations.

Identification of duplicated and stress-inducible Aox2b gene co-expressed with Aox1 in species of the Medicago genus reveals a regulation linked to gene rearrangement in leguminous genomes

In flowering plants, alternative oxidase (Aox) is encoded by 3-5 genes distributed in 2 subfamilies (Aox1 and Aox2). In several species only Aox1 is reported as a stress-responsive gene, but in the leguminous Vigna unguiculata Aox2b is also induced by stress. In this work we investigated the Aox genes from two leguminous species of the Medicago genus (Medicago sativa and Medicago truncatula) which present one Aox1, one Aox2a and an Aox2b duplication (named here Aox2b1 and Aox2b2). Expression analyses by semi-quantitative RT-PCR in M. sativa revealed that Aox1, Aox2b1 and Aox2b2 transcripts increased during seed germination. Similar analyses in leaves and roots under different treatments (SA, PEG, H2O2 and cysteine) revealed that these genes are also induced by stress, but with peculiar spatio-temporal differences. Aox1 and Aox2b1 showed basal levels of expression under control conditions and were induced by stress in leaves and roots. Aox2b2 presented a dual behavior, i.e., it was expressed only under stress conditions in leaves, and showed basal expression levels in roots that were induced by stress. Moreover, Aox2a was expressed at higher levels in leaves and during seed germination than in roots and appeared to be not responsive to stress. The Aox expression profiles obtained from a M. truncatula microarray dataset also revealed a stress-induced co-expression of Aox1, Aox2b1 and Aox2b2 in leaves and roots. These results reinforce the stress-inducible co-expression of Aox1/Aox2b in some leguminous plants. Comparative genomic analysis indicates that this regulation is linked to Aox1/Aox2b proximity in the genome as a result of the gene rearrangement that occurred in some leguminous plants during evolution. The differential expression of Aox2b1/2b2 suggests that a second gene has been originated by recent gene duplication with neofunctionalization. © 2013 Elsevier GmbH. All rights reserved.

Expressão de genes em sementes de lobeira (Solanum Lycocarpum St Hill) submetidas ao condicionamento fisiológico

Pós-graduação em Agronomia (Agricultura) - FCA

Ação alelopática de saxitoxinas e microcistinas em cianobactérias e microalgas verdes em condições controladas

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

Respostas de trocas gasosas e fluorescência da clorofila A em folhas verticais de Styrax camporum Pohl. (Styracaceae) submetida à deficiência hídrica

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

Características biométricas das sementes e descrição da resposta germinativa pelo modelo do tempo térmico em diferentes populações de Peltophorum dubium (Spreng.) Taub

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Determinação de ácido abscísico e respostas metabólicas em espécies congenéricas de savana e mata do cerrado paulista

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Resposta da soqueira de cana-de-açúcar a aplicação de potássio sob o sistema de cultivo conservacionista e seus efeitos na fisiologia da planta

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Influência do uso de telas de sombreamento coloridas (azul, vermelha e preta) na fisiologia da produção de mudas de Guanandi (Calophyllum brasiliensis)

Pós-graduação em Ciências Biológicas (Botânica) - IBB

Qualidade e conservação do morango tratado em pós-colheita com cloreto de cálcio e do armazenamento em atmosfera modificada ativa

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

Efeitos de auxinas e boro no enraizamento de estacas caulinares de louro (Laurus nobilis L.)

Pós-graduação em Agronomia (Horticultura) - FCA