Avaliação de parâmetros de estresse oxidativo em plantas de cana-de-açúcar tratadas com peróxico de hidrogênio

The genus Saccharum belongs to Poaceae family. Sugarcane has become important monocultures in Brazil due to their products: ethanol and sugar. The production may change between different regions from Brazil. This difference is related to soil, climatic conditions and temperature that promotes oxidative stress that may induce an early flowering. The aim of this work was to identify the effects of oxidative stress. In order to analyse this, sugarcane plants were submitted to oxidative stress using hydrogen peroxide. After this treatment, the oxidative stress were analyzed Then, the plant responses were analyzed under different approaches, using morphophysiological, biochemical and molecular tools. Thus, sugarcane plants were grown under controlled conditions and until two months they were subjected first to a hydroponics condition for 24 hours in order to acclimation. After this period, these plants were submitted to oxidative stresse using 0 mM, 10 mM, 20 mM and 30 mM hydrogen peroxide during 8 hours. The histomorphometric analysis allowed us to verify that both root and leaf tissues had a structural changes as it was observed by the increased in cell volume, lignin accumulation in cell walls. Besides, this observation suggested that there was a change in redox balance. Also, it was analyzed the activity of the SOD, CAT and APX enzymes. It was observed an increase in the SOD activity in roots and it was also observed a lipid peroxidation in leaves and roots. Then, in order to identify proteins that were differently expressed in this conditions it was used the proteomic tool either by bidimensional gel or by direct sequencing using the Q-TOF EZI. The results obtained with this approach identified more than 3.000 proteins with the score ranging from 100-5000 ions. Some of the proteins identified were: light Harvesting; oxygenevolving; Thioredoxin; Ftsh-like protein Pftf precusor; Luminal-binding protein; 2 cys peroxiredoxin e Lipoxygenase. All these proteins are involved in oxidative stress response, photsynthetic pathways, and some were classified hypothetical proteins and/or unknown (30% of total). Thus, our data allows us to propose that this treatment induced an oxidative stress and the plant in response changed its physiological process, it made changes in tissue, changed the redox response in order to survival to this new condition

Crescimento e nutrição de plantas de leucena (Leucaena leucocephala (Lam.) R. de Vit) sob salanidade

Excessive salt can to promote water soil retention, reducing your availability to plants. Besides, they can interfere in protoplasm metabolism. The plants ability to survive in salinity conditions is an important factor to geographic distribution and agriculture in salinized regions. The objective of this work was to verify the effects of the NaCl in the growth, dry matter distribution and N, K, Ca, Mg, Na, and Cl content in young plants. The experiment was conducted in 'Leonard' pots, with nutrient solutions, with NaCl ( 0, 25, 50 and 100 mmol L(-1)). Increasing of NaCl concentration reduces growth and total dry matter. There was an increase of N and K content, in shoots, and N and Mg content in roots. There was an reduction in Mg content in shoots, and reduction of Ca content in roots with increasing of NaCl. Leucaena plants were inefficient to exclude Na and Cl, in shoots principally.

Influência de genótipos de couve (Brassica oleracea L. var. acephala DC.) na biologia de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae)

Objetivou-se, com este trabalho, avaliar a influência de alguns genótipos de couve (Brassica oleracea L. var. acephala DC.) no desenvolvimento de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae). Os genótipos avaliados foram: Manteiga de Ribeirão Pires I-2620, Roxa I-919, Manteiga de São José, Manteiga de Monte Alegre, Pires 2 de Campinas, Couve Comum, Couve de Arthur Nogueira 2, Couve de Arthur Nogueira 1. Lagartas recém-eclodidas foram mantida em discos foliares de 8 cm de diâmetro para cada genótipo. Foram analisados os seguintes parâmetros: duração e viabilidade das fases larval e pupal, longevidade e fecundidade de adultos, utilizando análises paramétricas e de agrupamentos para interpretação dos dados. Observou-se um prolongamento em dias no ciclo de P. xylostella, aumento no peso de pupa e maiores valores de viabilidade e fecundidade, durante a segunda geração. O genótipo Couve de Arthur Nogueira 2 foi menos favorável ao desenvolvimento de P. xylostella nas duas gerações, e Couve Comum demonstrou maior influência negativa ao inseto na segunda geração. Manteiga de Ribeirão Pires I-2620 foi o mais suscetível nas duas gerações, agrupando com este na segunda geração Pires 2 de Campinas e Manteiga de São José.

Efeito de genótipos de maracujazeiro (Passiflora spp.) e da densidade larval na biologia de Dione juno juno (Cramer) (Lepidoptera: Nymphalidae)

Objetivou-se estudar em laboratório a biologia de Dione juno juno (Cramer), determinando-se os efeitos da densidade larval e da alimentação das larvas com folhas de nove genótipos de maracujazeiro. Foram analisados a duração, o peso e a viabilidade das fases larval e pupal e a longevidade dos adultos sem alimento. Verificou-se que a densidade de cinco lagartas por recipiente proporcionou melhor desenvolvimento do inseto do que uma e dez lagartas. Passiflora alata e P. setacea apresentaram resistência do tipo não-preferência para alimentação e/ou antibiose, enquanto o híbrido P. alata2 x P. macrocarpa apresentou não-preferência para alimentação, possivelmente associada à presença de compostos químicos com alto grau de repelência a D. juno juno ou a supressores de alimentação.

Biologia de Leptopharsa heveae Drake & Poor (Heteroptera: Tingidae) e a relação de suas exigências térmicas com a flutuação populacional em seringueira

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

Efeito de cultivares de algodoeiro sobre a biologia e capacidade predatória de Orius Insidiosus (say, 1832) (hemiptera: anthocoridae) predando Aphis Gossypii Glover, 1877 (Hemiptera: Aphididae)

The objective of this research was to determine the survival, reproduction and predaceous capacity of Orius insidiosus on cotton aphid Aphis gossypii. Cotton plants of Antares, CNPA7H and Acala 90 cultivars (respectively, without tricome, medium tricome density and high tricome density) were individualized and infested with 15 third/fourth instar nymphs of A. gossypii, and then first-instar nymphs of O. insidiosus were released on the plants. The evaluations were made daily, quantifying survival and nymphal development; the number of cotton aphids A. gossypii per day and total; the number of eggs and the population of the predator (number of insects by female); and the conversion efficiency of A. gossypii predaceous. The nymphal development did not differ according to the cotton cultivars. The Antares cultivar favored a higher daily predation rate for the 1st, 2nd and 4th instars and adults of O. insidiosus. The number of eggs and nymphs was smaller when O. insidiosus females were confined on the Acala 90 cultivar. According to the predation rate of O. insidiosus, the efficiency of alimentary conversion was determined for the Antares, CNPA7H and Acala 90 cultivars, being respectively, 4.28, 3.00 and 2.75 cotton aphid predation for each egg of the predator.

Estudo Comparativo da Biologia de Meloidogyne enterolobii (= M. mayaguensis) e Meloidogyne javanica em tomateiros com gene Mi

Visando conhecer a relação parasito hospedeiro de M. enterolobii em plantas com resistência a nematoides das galhas, estudos comparativos da biologia de M. enterolobii e M. javanica em tomateiros com o gene Mi foram conduzidos. O experimento foi conduzido em esquema fatorial 2x2, composto de dois porta-enxertos de tomateiro ('Magnet' e 'Helper M') e duas espécies de nematoides das galhas (M. enterolobii e M. javanica) com cinco repetições. As plantas foram inoculadas com 500 juvenis infectantes (J2) de M. enterolobii ou M. javanica. As raízes foram coletadas aos 3, 10, 17, 24 e 31 dias após a inoculação, coloridas com fucsina ácida, e dissecadas sob microscópio estereoscópico para a localização e contagem dos diferentes estádios de desenvolvimento dos nematoides. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Os resultados obtidos mostraram que, embora ambas as espécies tenham sido capazes de penetrar as raízes dos porta-enxertos de tomateiro, somente M. enterolobii conseguiu desenvolver-se normalmente, com as fêmeas maduras realizando suas posturas, a partir de 24 dias após a inoculação.

Atividades experimentais no ensino de biologia em escolas públicas do estado do Rio Grande do Norte, Brasil: caracterização geral e concepção de professores

Recent research has revealed that the majority of Biology teachers believe the practice of experimental activities as a didactical means would be the solution for the improvement of the Biology teaching-learning process. There are, however, studies which signal the lack of efficiency in such practice lessons as far as building scientific knowledge is concerned. It is also said that despite the enthusiasm on the teachers‟ part, such classes are rarely taught in high school. Several studies point pedagogical difficulties as well as nonexistence of a minimal infrastructure needed in laboratories as cause of low frequency in experimental activities. The poor teacher performance in terms of planning and development of classes; the large number of students per class; lack of financial stimulus for teachers are other reasons to be taken into account among others, in which can also be included difficulties of epistemological nature. That means an unfavorable eye of the teacher towards experimental activities. Our study aimed to clarify if such scenario is generalized in high schools throughout the state of Rio Grande do Norte Brazil. During our investigation a sample of twenty teaching institutions were used. They were divided in two groups: in the first group, five IFRN- Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte schools. Two of those in Natal, and the other three from the country side. The second group is represented by fifteen state schools belonging to the Natal metropolitan area. The objectives of the research were to label schools concerning laboratory facilities; to identify difficulties pointed by teachers when performing experiment classes, and to become familiar with the conceptions of the teachers in regarding biology experiment classes. To perform such task, a questionnaire was used as instrument of data collecting. It contained multiple choice, essay questions and a semi-structured interview with the assistance of a voice recorder. The data analysis and the in loco observation allowed the conclusion that the federal schools do present better facilities for the practice of experimental activities when compared to state schools. Another aspect pointed is the fact that teachers of federal schools have more time available for planning the experiments; they are also better paid and are given access a career development, which leads to better salaries. All those advantages however, do not show a significantly higher frequency regarding the development of experiments when compared to state school teachers. Both teachers of federal and state schools pointed infra-structure problems such as the availability of reactants, equipments and consumption supplies as main obstacle to the practice of experiments in biology classes. Such fact leads us to conclude that maybe there are other problems not covered by the questionnaire such as poor ability to plan and execute experimental activities. As far as conceptions about experimental activities, it was verified in the majority of the interviewees a inductive-empiric point of view of science possibly inherited during their academic formation and such point of view reflected on the way they plan and execute experiments with students

Genética e biologia reprodutiva de vriesea minarum (Bromeliaceae): em busca de estratégias de conservação no quadrilátero ferrífero, minas gerais

Vriesea minarum is a rupiculous bromeliad species, with naturally fragmented populations, restricted to the Iron Quadrangle, Minas Gerais, Brazil. It is a threatened species, which is suffering from habitat loss due to the growth of cities and mining activities. The knowledge of genetic variability in plant populations is one of the main branches of conservation genetics, linking genetic data to conservation strategies while the knowledge about plant reproductive biology can aid in understanding key aspects of their life story, as well as in the comprehension of their distribution and survival strategies. Thus, the study of diversity, richness, and genetic structure, as well as the reproductive biology of populations of V. minarum can contribute to the development of conservation actions. Chapter 1 presents the transferability of 14 microsatellite loci for V. minarum. Among the results of this chapter, we highlight the successful transferability of 10 microsatellite loci described for other species of Bromeliaceae, all of which are polymorphic. In Chapter 2, we present the genetic analyses of 12 populations of V. minarum that are distributed throughout the Iron Quadrangle. We used the 10 microsatellite loci tested in Chapter 1. The results show a low population structuring (Fst = 0.088), but with different values of genetic richness (mean = 2.566) and gene diversity (mean = 0.635) for all populations; and a high inbreeding coefficient (Gis = 0.376). These may be the result of pollinators action and/or efficient seed dispersal, thus allowing a high connectivity among populations of naturally fragmented outcrops. The reproductive biology and floral morphology of a population of V. minarum, located in the Parque Estadual da Serra do Rola-Moça, are studied in Chapter 3. This reserve is the only public environmental protection area where the species occurs. As a result of field experiments and observations, we found that the species has its flowering period from January to March, with flowers that last for two days and that it has a mixed pollination syndrome. It is primarily alogamous, but also has the capacity to be self-ferilized. It is expected that data obtained in chapters 1, 2 and 3 serve as basis for other studies with species from the ferruginous rocky fields, since until now, to our knowledge, there are no other survey of endemic species from the Iron Quadrangle, seeking to merge the genetic knowledge, with the data of the reproductive biology, with the ultimate aim of biodiversity conservation. Considering the great habitat loss for the species by mining, it becomes crucial to analyze the creation of new protected areas for its conservation

Biologia de Iphiseiodes zuluagai Denmark & Muma (Acari: Phytoseiidae)

Iphiseiodes zuluagai Denmark & Muma (Acari: Phytoseiidae) é um ácaro predador comumente encontrado em plantas cítricas (Citrus spp.). Alimentado com pólen de mamoneira (Ricinus communis ) e a 25 ± 2°C, 70 ± 10% de UR e 14 horas de fotofase, a maioria das larvas eclodiu entre 12 e 24 horas. A duração do estágio de larva foi freqüentemente em torno de 24 horas, e a duração das fases de protoninfa e deutoninfa entre 24 e 48 horas. O ciclo de ovo a adulto durou 5 a 6 dias. A estimativa da capacidade inata de crescimento da população (r m) foi 0,122 fêmeas/ fêmea/ dia; a duração média de uma geração (T) 18,7 dias; a taxa líquida de reprodução (Ro) 9,82 fêmeas/ fêmea e a razão finita de aumento (1)1,13.

Interação silício-imidacloprid no comportamento biológico e alimentar de Schizaphis Graminum (Rond.) (Hemiptera: Aphididae) em plantas de trigo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo do padrão morfológico e da biologia Eutetranychus banksi (McGregor) (Acari: Tetranychidae) de diferentes locais e hospedeiros

Pós-graduação em Biologia Animal - IBILCE

Biologia de Tenuipalpus heveae Baker (acari, Tenuipalpidae) em três clones de Fevea brasileinsis Muell. Arg. (Euphorbiaceace)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seleção de plantas hospedeiras pela aranha bromelícola Psecas chapoda (Salticidae)

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

Engenheiros dos ecossistemas em plantas: modificações arquiteturais de folhas por largatas de Lepidoptera influenciam a estrutura de comunidades de artrópodes

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