Boro afeta o crescimento e a ultra-estrutura da mamoneira

A mamoneira é uma oleaginosa com grande potencial para a geração de renda na agricultura familiar e para produção de matéria prima para a indústria química e setor energético brasileiro, especialmente em regiões do semi-árido nordestino. A deficiência de boro (B) ocorre de forma generalizada no Brasil e a aplicação excessiva deste micronutriente pode causar toxicidade. Este estudo avalia o desenvolvimento e os efeitos ultra-estruturais de deficiência e toxicidade de boro em mamoneira. O experimento foi realizado em condições de casa de vegetação, com vasos de 10 L de solução nutritiva. Foram utilizados três tratamentos: testemunha (sem B); 0,27 e 5,40 mg L-1 B, uma planta por vaso, em delineamento experimental inteiramente ao acaso com três repetições. A produção de matéria seca de cada parte da planta foi avaliada e o teor de boro determinado. Foram observados os efeitos morfológicos e as alterações na ultra-estrutura celular nas folhas e pecíolos, através da técnica de microscopia eletrônica de transmissão e varredura. A produção de matéria seca da mamoneira foi afetada em condições de deficiência de boro, mas não em condições de toxicidade (5,4 mg L-1 B). Neste último tratamento foram constatadas cloroses nos bordos de folhas velhas e ausência de grânulos de amido. Na omissão de boro, as plantas apresentaram deformação de folhas novas, morte do meristema apical, engrossamento da lamela média, ausência de grânulos de amido nos cloroplastos e desorganização dos vasos condutores do pecíolo. O desenvolvimento e a produção da mamoneira são afetados em condições de deficiência de boro mas não na condição de toxicidade.The cultivation of oleaginous plants like the castor bean guarantees employment for agricultural families and can contribute in energy and chemical sectors, especially in the northeastern semi-arid regions of Brazil. Boron (B) deficiency is a widespread nutritional disorder despite the fact that various anthropogenic sources with high B content may increase soil B to toxic levels for plants. The present study was designed to investigate the ultrastructural effects of boron deficiency and toxicity on castor bean plants which were grown under greenhouse condition using plastic containers with 10 L of nutrient solution. Boron treatments comprised: control (no B); 0.27 mg L-1, 5.40 mg L-1 B pots (one plant per pot), tested in a completely randomized design with three replicates. The dry matter of all plant parts and B concentration were determined. Cellular ultrastructure was evaluated by transmission and scanning electron microscopy on samples of leaves and petioles. Dry matter yield was affected by the B absence treatment but there was no difference for the 5.4 mg L-1 B (toxic conditions) treatment. A marginal leaf burn at edge and tips of oldest leaves and absence of starch granules in chloroplasts were noted for the B toxicity treatment. The deformation of the youngest leaves, the death of the apical meristem as well as the swelling of the middle lamella, absence of starch granules in chloroplasts and petiole vessels untidily were observed in the B absent treatment. It is concluded that the production and development of castor bean plants is affected by boron deficiency, but not for boron toxicity conditions

In vitro culture of sugarcane exposed to different light sources

O objetivo deste trabalho foi avaliar o efeito de diferentes comprimentos de onda no desenvolvimento in vitro de mudas de cana‑de‑açúcar. Explantes foram submetidos a quatro tratamentos de diodos emissores de luz (LED): 100% azul; 70% azul + 30% vermelha; 30% azul + 70% vermelha; 100% vermelha, além do controle com lâmpada fluorescente branca. As plântulas foram avaliadas quanto a: número de brotações; altura; massa de matéria fresca e seca; e conteúdo de carotenoides e das clorofilas a e b. Observou-se desmanche dos tilacoides nos cloroplastos, proporcional ao aumento na incidência de luz vermelha. O porte das mudas diminui com o aumento na incidência de luz vermelha.The objective of this work was to evaluate the effect of different wave length on the in vitro development of sugarcane seedlings. Explants were subjected to four light emitting diodes (LED): 100% blue; 70% blue + 30% red; 30% blue + 70% red; 100% red, besides the control with white fluorescent lamp. Seedlings were evaluated for: number of shoots; height; fresh and dry matter mass; and contents of carotenoids and chlorophyll a and b. It was observed thylakoid disarrangement in the chloroplast, proportional to the increasing incidence of red light. The size of the in vitro produced seedlings reduces with the increase of red light incidence

In vitro culture of sugarcane exposed to different light sources

The objective of this work was to evaluate the effect of different wave length on the in vitro development of sugarcane seedlings. Explants were subjected to four light emitting diodes (LED): 100% blue; 70% blue + 30% red; 30% blue + 70% red; 100% red, besides the control with white fluorescent lamp. Seedlings were evaluated for: number of shoots; height; fresh and dry matter mass; and contents of carotenoids and chlorophyll a and b. It was observed thylakoid disarrangement in the chloroplast, proportional to the increasing incidence of red light. The size of the in vitro produced seedlings reduces with the increase of red light incidence.O objetivo deste trabalho foi avaliar o efeito de diferentes comprimentos de onda no desenvolvimento in vitro de mudas de cana-de-açúcar. Explantes foram submetidos a quatro tratamentos de diodos emissores de luz (LED): 100% azul; 70% azul + 30% vermelha; 30% azul + 70% vermelha; 100% vermelha, além do controle com lâmpada fluorescente branca. As plântulas foram avaliadas quanto a: número de brotações; altura; massa de matéria fresca e seca; e conteúdo de carotenoides e das clorofilas a e b. Observou-se desmanche dos tilacoides nos cloroplastos, proporcional ao aumento na incidência de luz vermelha. O porte das mudas diminui com o aumento na incidência de luz vermelha.13031307Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Biochemical and histological characterization of tomato mutants

Biochemical responses inherent to antioxidant systems as well morphological and anatomical properties of photomorphogenic, hormonal and developmental tomato mutants were investigated. Compared to the non-mutant Micro-Tom (MT), we observed that the malondialdehyde (MDA) content was enhanced in the diageotropica (dgt) and lutescent (l) mutants, whilst the highest levels of hydrogen peroxide (H2O2) were observed in high pigment 1 (hp1) and aurea (au) mutants. The analyses of antioxidant enzymes revealed that all mutants exhibited reduced catalase (CAT) activity when compared to MT. Guaiacol peroxidase (GPOX) was enhanced in both sitiens (sit) and notabilis (not) mutants, whereas in not mutant there was an increase in ascorbate peroxidase (APX). Based on PAGE analysis, the activities of glutathione reductase (GR) isoforms III, IV, V and VI were increased in l leaves, while the activity of superoxide dismutase (SOD) isoform III was reduced in leaves of sit, epi, Never ripe (Nr) and green flesh (gf) mutants. Microscopic analyses revealed that hp1 and au showed an increase in leaf intercellular spaces, whereas sit exhibited a decrease. The au and hp1 mutants also exhibited a decreased in the number of leaf trichomes. The characterization of these mutants is essential for their future use in plant development and ecophysiology studies, such as abiotic and biotic stresses on the oxidative metabolism

Morphological Studies on the Mature Worker Larvae of Paratrechina fulva (Hymenoptera, Formicidae)

The ant Paratrechina fulva is native to Brazil, but has spread to other countries where it has become a serious pest. Their larvae are known from a preliminary description made without the aid of scanning electron microscopy. The present investigation aimed at describing the mature worker larvae of this species in deeper detail, while identifying useful morphological characters for taxonomy and cladistics. General morphological traits typical of Paratrechina larvae described so far were also confirmed with this species, particularly regarding body shape, types of hairs, and distribution pattern of head sensilla, but P fulva presented unusually shaped mandibles.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Morphological Studies on the Mature Worker Larvae of Paratrechina fulva (Hymenoptera, Formicidae)

The ant Paratrechina fulva is native to Brazil, but has spread to other countries where it has become a serious pest. Their larvae are known from a preliminary description made without the aid of scanning electron microscopy. The present investigation aimed at describing the mature worker larvae of this species in deeper detail, while identifying useful morphological characters for taxonomy and cladistics. General morphological traits typical of Paratrechina larvae described so far were also confirmed with this species, particularly regarding body shape, types of hairs, and distribution pattern of head sensilla, but P fulva presented unusually shaped mandibles.FAPESP[2006/02115-6

Description of the Immatures of Workers of the Weaver Ant, Camponotus textor (Hymenoptera: Formicidae)

The weaver ants Camponotus textor (Forel) (Hymenoptera: Formicidae) are native to Central and South America, where they use their larvae to build silken nests by sewing tree leaves together. Few Studies have been conducted with this species, and little is known about the morphology of their larvae. Tie present paper estimated the number of larval instars of C. textor and presents a detailed morphological description of each immature stage based on light and electron microscopic observations. The number of larval in stars was estimated as four based oil the frequency distribution of larval head widths. Tic larvae of this species presented some typical characteristics of Camponotus (Mayr) larvae: body shape `pogonomyrmecoid`, ten pairs of spiracles, antennae with three sensilla, conspicuous `chiloscleres` on the labrum, and mature larvae with pronounced labial pseudopalps. Unprecedented characteristics would include: great diversity of body hair types, and `camponotoid` mandibles but with four medial denticles. This information can aid biological and taxonomic studies with these ants, and may be useful for ant systematics.CAPES Institutio

Morphological Notes on the Worker and Queen Larvae of the Thief Ant Solenopsis helena (Hymenoptera, Formicidae, Myrmicinae) from Brazil

Young and mature larvae of queen and workers of the thief ant, Solenopsis helena, are herein described for the first time. Specimens were treated and described by usual methods of light and scanning electron microscopy. Many of the observed characteristics confirmed traits of the thief ant larva, reinforcing the assumption that they are a distinct group from fire ants. The larva of S. helena can be recognized from other close species by details of the mouthparts, but seem extensively similar to Solenopsis molesta. These findings are useful for taxonomic studies and phylogenetic inferences.Larvas de diferentes tamanhos de operarias e rainhas de Solenopsis helena são descritas. Os espécimes coletados em São Paulo, Brasil, foram medidos e descritos por meios convencionais de microscopia ótica e eletrônica de varredura. As larvas desta espécie diferem de outras espécies próximas por detalhes das peças bucais, mas parecem ser muito semelhantes a descrições anteriores de Solenopsis molesta. Muitos caracteres distintos de larvas das formigas do antigo subgênero Diplorohptrum foram aqui confirmados, sugerindo que realmente são um grupo distinto de formigas dentro do gênero Solenopsis. Estas informações são uteis em estudos maiores de filogenia e taxonomia do grupo

Pycnoscelus surinamensis (Linnaeus, 1758) (Blaberoidea: Blaberidae), a cockroach with a possible association with the ant Brachymyrmex cordemoyi Forel, 1895 (Hymenoptera: Formicidae) and which may be exhibiting a domiciliation trend

In the present paper, we report on the occurrence of the cockroach Pycnoscelus surinamensis (Linnaeus, 1758) in Brachymyrmex cordemoyi Forel, 1895 nests, indicating a possible symbiosis between these two species. Also, the finding of intradomicile P. surinamensis nymphs may indicate this species is extending its habitat to human habitations, i.e. changing its ecological category from peridomestic to domestic5313739sem informaçã