Fernando Pereira Monteiro

Bioatividade de óleos essenciais no controle de Botrytis cinerea isolado de morangueiro

This study aimed evaluates essential oils in Botrytis cinerea isolates growth, which causes gray mould on strawberry. Were tested essential oils of lemon grass, palmrose, citronella, clove, cinnamon, mint, lavender, tangerine, eucalyptus, tea tree, rosemary and orange. The oils were analyzed in gas chromatograph attached to mass detector for identifying the mainly oils components. Were evaluated mycelial growth, conidia production and conidia germination of B. cinerea, with oil incorporation in culture medium. Were conducted an evaluation of oils volatile components and the efficiency of oils in fungicide-resistant isolate. For each test, different oils showed efficiency, however lemongrass, palmarosa, cinnamon and mint showed the best effects in all tests. All treatments demonstrated similar effects to recommended fungicide for the culture, which had methyl thiophanate. Two treatments (lemon grass and cinnamon oils), were effective against resistant isolate. Essential oils are shown as promising option for development of possible product for plant disease management.

Profundidade de semeadura e crescimento inicial de espécies forrageiras utilizadas para cobertura do solo

O uso do consorcio entre plantas de cobertura e culturas anuais, no Cerrado, tem sido pratica cada vez mais difundida, pela possibilidade de implantacao das forrageiras durante o desenvolvimento das culturas anuais, atraves da diferenca de profundidade e sistema de semeadura. Objetivou-se, neste trabalho avaliar a emergencia e algumas caracteristicas agronomicas de quatro especies de plantas de cobertura, em diferentes profundidades, visando ao seu emprego na consorciacao e sobressemeadura em culturas anuais. O experimento foi conduzido em casa-de-vegetacao, no delineamento experimental de blocos ao acaso, em arranjo fatorial 4 x 7, composto pelas plantas de cobertura Brachiaria brizantha, B. decumbens, B. ruziziensis e Panicum maximum cv. Tanzânia, e por seis profundidades de semeadura e um sistema de cobertura de sementes (0 sem cobertura, 0 com cobertura, 1, 4, 8, 10 e 15 cm). As sementes foram semeadas em vasos e as plantas cultivadas por 40 dias. Avaliou-se o indice e o tempo de emergencia, a altura de plantas, a fitomassa verde e seca da parte aerea, a area foliar, a fitomassa seca radicular e a densidade de comprimento radicular. O maior desenvolvimento das plantas estudadas foi detectado nas semeaduras ate 1 cm de profundidade. O P. maximum nao apresentou aptidao para uso em consorcio com culturas anuais.Nao se recomenda a semeadura das plantas de cobertura a partir de 10 cm.

Diversity of Trichoderma species isolated from dead branches and sapwood of Theobroma cacao trees

The diversity of Trichoderma species associated with cacao trees in Bahia state, Brazil, was investigated. A total of 100 isolates, 76 from sapwood and 24 from dead branches, were characterized by phylogenetic analysis of the internal transcribed spacer (ITS) of the ribosomal DNA and the translation elongation factor (tef1) of the RNA polymerase. Sixteen known and five putative new species were identified among the isolates used in this study. Trichoderma lentiforme was the most abundant species and exclusively found in cacao sapwood while T. parareesei was the most abundant and exclusively isolated from dead branches. The knowledge on the diversity of these fungi may contribute to their future exploitation in biotechnological applications and biological control of plant diseases.

Genetic diversity and population densities of endophytic Bacillus spp. in yam plants

AbstrAct: This study was conducted as a first step in exploiting endophytic bacteria to improve yam production. Little information is available on population densities and genetic diversity of endophytic bacteria in yam cultivated in tropical regions. This study demonstrated that higher densities of total endophytic bacteria and Bacillus occur in the interior of roots and decrease as the sampled plant organ departs from soil. Bacillus represents approximately 1% of the total bacterial endophytic population. Random Amplified Polymorphic DNA (RAPD) analyses performed with 88 randomly-selected Bacillus isolates bAsIc ArEA - Note Genetic diversity and population densities of endophytic Bacillus spp. in yam plants Jorge Teodoro de Souza 1 *, Ana Claudia Oliveira Souza Santos 2 , Fernando Pereira Monteiro , Mariah Rodrigues Batista 2 , Patricia Oliveira dos Santos 3 , Larissa Ferreira Carvalho 1 , Elida Barbosa Correa 4 1.Universidade Federal de Lavras - Departamento de Fitopatologia - Lavras (MG), Brazil. 2.Universidade Federal do Reconcavo da Bahia - Centro Ciencias Agrarias, Ambientais e Biologicas - Cruz das Almas (BA), Brazil.3.Instituto Federal de Educacao - Ciencia e Tecnologia da Bahia - Santa Ines (BA), Brazil.4.Universidade Estadual da Paraiba - Campina Grande (PB), Brazil.

GFP-fluorescent protein on the study of blister spot in coffee plants

In Brazil, Colletotrichum gloeosporioides is associated with a complex of symptoms in coffee culture. Although this pathogen had its pathogenesis observed and identified, its importance has still been questioned due to its several endophytic forms, raising doubts as to the real importance of the pathosystem. The aim of this study was to demonstrate, by using an isolate transformed with the gene gfp, the infection and colonization capability of C. gloeosporioides in coffee seedlings. After the fourth day of inoculation, manifestation of symptoms as punctual necrosis could be observed, which progressed during the evaluation period, culminating in the death of seedlings. Epifluorescence microscopy confirmed the presence of the pathogen in the seedlings, as well as the visualization of internal colonization of tissues, acervulus formation and conidium production, confirming that it was responsible for the observed symptoms.

Extratos de plantas de cobertura no desenvolvimento de Sclerotinia sclerotiorum

Plant extracts may interfere with the life cycle of pathogens by promoting or inhibiting development. Based on this property, the present study aimed to evaluate the effect of aqueous extracts of the COVER plants crotalaria (Crotalaria juncea), brachiaria (Brachiaria ruziziensis), panicum maximum grass (Panicum maximum cv. mombaca), millet (Pennisetum glaucum), pigeon pea dwarf bean (Cajanus cajan.) and stylosanthes (Stylosanthes macrocephala x Stylosanthes capitata) on the mycelial growth, mycelial and carpogenic germination of sclerotia, and ascospore germination of Sclerotinia sclerotiorum. The stages of the experiment were carried out in a greenhouse, growth chambers and laboratory. The concentrations of the extracts used were 1%, 5%, 10% and 25%. To assess the influence of extracts on the mycelial and carpogenic germination of the sclerotia only the concentration of 25% was used. The results on the mycelial growth showed that the Stylosanthes sp. plant extract was effective for inhibiting the pathogen only at concentration of 25%. For mycelial germination of sclerotia, it was found that with the exception of Stylosanthes sp. the extracts induced germination 12 hours after the experiment. In regard to the germination of ascospores, only the extract from Stylosanthes sp. successfully prevented germination.