Severina Rodrigues de Oliveira Lins

Controle alternativo da podridão peduncular em manga

The aim of this study was to evaluate the effect of alternative products in mango sleeves inoculated challenged with Lasiodiplodia theobromae and its influence on the mycelial growth of the pathogen in vitro. Mangoes were treated with: potassium phosphate (50, 100 and 150), hidroxidobenzoico acid (5, 10 and 15), calcium chloride (0.13, 0.26 and 0.39) (in mmol), ultraviolet light ( 10, 20 and 30 min.), extracts of garlic, melons of the Caetano, bark of mango (25, 50 and 75%) and water (control). The design was a split plot. 106 con./mL was inoculated immediately after each treatment (T1), twelve hours after (T2) and twenty-four hours after (T3). In T1, the best treatments were PO (50 mmol) and CC (0.13 mmol). T2 in there were CC (0.13 mmol), AH (5 mmol), EA (25%) and FP (100 mmol). In T3 there was no difference between treatments. In vitro treatments were mixed into the culture medium. After solidification it was placed in the center of each plate, structures of the phythopathogen. The model was in DIC with 6 replications. After 48 hours it was measured the diameter of the colony. The best treatments were FP (100 and 150 mmol), ECM (50 and 75%) and EA (50%).

Efeito do estádio de maturação, tipo de inóculo e local de inoculação na severidade da podridão peduncular em manga

The mango crop is one of the principal activities of Brazilian agribusiness, and it has grown steadily over recent years. Postharvest rots are responsible for great losses in fruit storage, with prominence to steam-end rot, caused by Lasiodiplodia theobromae and Fusicoccum parvum. The objective of this work was to compare isolates of the species L. theobromae and F. parvum on the aggressivity, inoculum type, inoculation place and state of ripeness in cv. Tommy Atkins. The aggressivity test was carried out with five isolates of L. theobromae and 10 isolates of F. parvum. Isolates L2 and L5 of L. theobromae and isolates F6 and F10 belonging to the species F. parvum were considered the most aggressive. These isolates were tested in relation to the state of ripeness (2; 2,5; 3; 4 and 5), inoculum type (disc of PDA containing structures of the plant pathogens and conidia suspension - 105 conidium/mL) and inoculation place (peduncle region and equatorial area) on the mango. In general, the more mature the fruit, the greater the severity of the disease for isolates of the two plant pathogens, independent of the place of inoculation and the type of inoculum. In the earliest states of ripeness the smallest lesions were observed when inoculated with conidium suspension. As for the inoculation place, no marked influence was observed for the isolates of the plant pathogens studied

Low doses of gamma radiation in the management of postharvest Lasiodiplodia theobromae in mangos

The postharvest life of mango is limited by the development of pathogens, especially fungi that cause rot, among which stands out the Lasiodiplodia theobromae. Several control methods have been employed to minimize the damages caused by this fungus, chemical control can leave residues to man and nature; physical control by the use of gamma radiation in combination with modified atmosphere and cold storage. The use of gamma radiation helps to reduce the severity of the pathogen assist in the ripening process of fruits, even at low doses (0.25, 0.35 and 0.45 kGy) chemical properties such as pH, soluble solids, acid ascorbic, titratable acidity and also the quality parameters of the pulp showed no damage that are ideal for trade and consumption of mangoes. This treatment can be extended for use in the management of diseases such as natural infections for penducular rot complex that has as one of L. theobroma pathogens involved.

Uso de antagonistas e produtos alternativos no manejo pós-colheita de podridão mole em pimentão

Visando o controle da podridao mole causada por Pectobacterium carotovorum subsp. carotovorum (Pcc) em pimentao, foram avaliados 10 tratamentos: Bacillus spp.: isolado C116 (B. pumilus); Leveduras: isolados Lma (Rhodotorula aurantiaca) e Lms (R. glutinis); Fosfito de potassio e calcio; Fontes de calcio: CaCl2, Ca(CO3)2 e Ca(SO4)2; fungicida/bactericida orgânico Antica®; antibiotico Kasumin®. Apos a determinacao da concentracao dos antagonistas e produtos alternativos pelo teste do antibiograma, foi realizado o teste in vivo, pela inoculacao do patogeno, seis horas apos os tratamentos com os antagonistas e produtos alternativos. Foram determinados o Periodo de Incubacao (PI), Severidade da doenca (SEV), Reducao da severidade da doenca (RSD%) e Area abaixo da curva de progresso da doenca (AACPD). Todos os tratamentos testados apresentaram maiores valores de PI e RSD% e menores valores de SEV e AACPD quando comparados a testemunha. Fosfito de calcio, C116, Lms, Lma e fosfito de potassio foram significativamente superiores quando comparados como demais tratamentos. Pcc foi resistente ao Kasumin®, possuindo SEV e AACPD que nao diferiram significativamente da testemunha.

Podridão peduncular em manga: patogenicidade, agressividade e caracterização de isolados pela análise isoenzimática

Thirty-four Lasiodiplodia theobromae isolates collected from different organs of mango trees, in two different seasonal periods, at different geographical regions, were evaluated for pathogenicity, aggressiveness and production of enzymes on specific solid substrates and in polyacrylamide gel systems. Regardless of the organ from which they were collected, all isolates were pathogenic when inoculated into mango, differing in the aggressiveness degree, based on which they were separated into three groups: high, medium and low aggressiveness. The amylolytic, cellulolytic, lipolytic and proteolytic activities were estimated by means of enzyme diffusion on specific solid medium and measurement of the substrate degradation halo. The activities of enzymes a-esterase, â-esterase, leucineaminopeptidase, acid phosphatase and total protein were analyzed on polyacrylamide gels with specific revelation media for each analysis. The electrophoretic patterns and the analysis of extracellular enzymes showed polymorphism, evidencing the diversity in the genetic basis of isolates, regardless of collection period, geographic region and organ from which the isolates were collected.

FREQUÊNCIA DE FUNGOS QUIESCENTES E MANEJO ALTERNATIVO DA PODRIDÃO PEDUNCULAR EM MAMÃO NA PÓS-COLHEITA

The aim of this study was to evaluate the frequency of quiescent fungi and the effect of phosphites under modified atmosphere on Lasiodiplodia theobromae in papaya. The fruits were treated with a range of doses of phosphites and their actions evaluated under conditions of ambient and modified atmosphere. Of the eight fungal genera found, Lasiodiplodia was the most common. No interaction was observed between the evaluated factors and only atmosphere and dose were independently significant. The usage of phosphites and modified atmosphere reduced the severity of the disease, and did not affect the chemical properties of the fruits.