ABSTRACT
Activity differences of the first (phenylalanine ammonia lyase, PAL) and the last (cinnamyl alcohol dehydrogenase, CAD) enzymes of phenylpropanoid pathway in the roots of resistant (Yangambi Km5 and Anaikomban) and susceptible (Nendran and Robusta) banana cultivars caused by root lesion nematode, Pratylenchus coffeae, were investigated. Also, the accumulation of phenolics and deposition of lignin polymers in cell walls in relation to resistance of the banana cultivars to the nematode were analyzed. Compared to the susceptible cultivars, the resistant cultivars had constitutively significantly higher PAL activity and total soluble and cell wall-bound phenolics than in susceptible cultivars. The resistant cultivars responded strongly to the infection of the nematode by induction of several-time higher PAL and CAD enzymes activities, soluble and wall-bound phenolics and enrichment of lignin polymers in cell wall and these biochemical parameters reached maximum at 7th day postinoculation. In addition, profiles of phenolic acid metabolites in roots of Yangambi Km5 and Nendran were analyzed by HPLC to ascertain the underlying biochemical mechanism of bananas resistance to the nematode. Identification and quantification of soluble and cell wall-bound phenolic acids showed six metabolites and only quantitative, no qualitative, differences occurred between the resistant and susceptible cvs. and between constitutive and induced contents. A very prominent increase of p-coumaric, ferulic and sinapic acids, which are precursors of monolignols of lignin, in resistant cv. was found. These constitutive and induced biochemical alterations are definitely the chemical defenses of resistant cvs. to the nematode infection.
Subject(s)
Alcohol Oxidoreductases/genetics , Alcohol Oxidoreductases/metabolism , Animals , Disease Resistance/genetics , Metabolic Networks and Pathways , Musa/enzymology , Musa/genetics , Musa/growth & development , Musa/parasitology , Nematoda/genetics , Nematoda/pathogenicity , Phenols/chemistry , Phenols/metabolism , Phenylalanine Ammonia-Lyase/genetics , Phenylalanine Ammonia-Lyase/metabolism , Plant Diseases/genetics , Plant Diseases/parasitology , Plant Roots/enzymology , Plant Roots/metabolism , Polymers/chemistry , Propanols/chemistry , Propanols/metabolismABSTRACT
Este estudo teve o objetivo de selecionar isolados do fungo entomopatogênico Metarhizium anisopliae para o controle de adultos de Rhynchophorus palmarum (L.) (Coleoptera: Curculionidae) e avaliar a compatibilidade de agrotóxicos utilizados nesta cultura com o isolado que ocasionasse maior mortalidade dos adultos. Para tal, adultos do inseto foram imersos em suspensões de seis isolados do fungo na concentração de 109 conídios.mL-1 e, após 24 dias, o isolado IBCB 348 causou maior mortalidade (87,5%) e foi utilizado para o teste de compatilibidade, por meio do cálculo da fórmula de T, com inseticidas, herbicidas e fungicidas comerciais utilizados na cultura. Nenhum dos fungicidas e herbicidas testados foram compatíveis com o patógeno. Os inseticidas Calypso, Dipterex 500 e Sevin 480 SC, na concentração mínima recomendada pelo fabricante, foram os únicos produtos classificados como compatíveis com o isolado IBCB 348 de M. anisopliae.
This study was aimed to screen the entomopathogenic fungus Metarhizium anisopliae for the control of Rhynchophorus palmarum (L.) (Coleoptera: Curculionidae) adults and to evaluate the compatibility of agrochemicals used in this crop with the strain that caused the highest insect mortality. To this end, adult insects were immersed in suspensions of 6 strains at a concentration of 109 conidia.mL-1, and after 24 days the isolate IBCB 348 caused the highest mortality (87.5%) and was used in the compatibility test, using calculations by way of the T formula, with commercial insecticides, herbicides and fungicides used in the crop. Among the tested strains, IBCB 348 was the most efficient in the control of this pest, causing 87.5% of weevil mortality. None of the tested fungicides and herbicides were compatible with the pathogen. The insecticides Calypso, Dipterex 500 and Sevin 480 SC, at the lowest dose recommended by the manufacturer, were the only products classified as compatible with the strain IBCB 348 of M. anisopliae.
Subject(s)
Coleoptera , Pest Control, Biological/methods , Musa/parasitology , Metarhizium , Pesticides/analysisABSTRACT
The presence of the red palm mite, Raoiella indica Hirst is recorded for the first time in South America. High populations and severe damages caused by this new invasive mite were found on coconut and banana leaves in Sucre (10° 27' 47" N and 64°10' 38" W) and Monagas (9º46'60" N and 63º12'0" W) states in northeastern Venezuela.
Se registra la presencia de Raoiella indica Hirst por primera vez en Sur América. Altas poblaciones y daños severos causados por esta nueva especie invasiva fueron encontrados en hojas de coco y banana en los estados nororientales de Venezuela, Sucre (10° 27' 47" N y 64°10' 38" W) y Monagas (9º46'60" N y 63º12'0" W).
Subject(s)
Animals , Mites , Cocos/parasitology , Musa/parasitology , VenezuelaABSTRACT
The following three species of Ceratopogonidae were collected breeding in the rhizomatous herb Phenakospermum guyannense Endl., 1833 in the vicinity of Manaus, Brazil, a new species, Culicoides (Mataemyia) felippebauerae Spinelli, Forcipomyia (Forcipomyia) genualis (Loew), and F. (Phytohelea) musae Clastrier & Dellécole. C. (M.) felippebauerae is described and illustrated as adult, pupa, and fourth instar larva, the adult compared with the adult of C. barthi Taveres and Souza and larva and pupa with those of C. dicrourus Wirth & Blanton and C. macieli Tavares & Ruiz, the only species with known immatures in the subgenus. The pupa and fourth instar larva of F. (P.) musae are described and illustrated and compared with immatures of F. (P.) edwardsi Saunders.
Subject(s)
Animals , Female , Male , Ceratopogonidae/anatomy & histology , Ceratopogonidae/classification , Musa/parasitology , Brazil , Larva/anatomy & histology , Pupa/anatomy & histologyABSTRACT
Em maio de 2005, foi constatada a infestação de lagartas de Antichloris eriphia (Fabr.) (Lepidoptera: Arctiidae) e Calligo illioneus (Cramer) (Lepidoptera: Nymphalidae), pragas da bananeira, em plantas de Heliconia latispatha Benth. com seis meses de idade, plantadas próximas a cultura de bananeiras em Jaguariúna, SP. Trata-se da primeira observação do ataque de C. illioneus em H. latispatha no Brasil.
In mid-May 2005, the caterpillars Antichloris eriphia (Fabr.) (Lepidoptera: Arctiidae) and Calligo illioneus (Cramer) (Lepidoptera: Nymphalidae) which are banana tree pests, were found attacking six-month old stalks of Heliconia latispatha Benth., planted near a banana tree plantation in Jaguariuna, SP, Brazil. The attack by C. illioneus is observed by the first time in Brazil.
Subject(s)
Animals , Heliconiaceae , Lepidoptera/physiology , Musa/parasitology , Behavior, AnimalABSTRACT
OBJECTIVE: Identification of larvae that inest bananas and investigating its habits. DESIGN: Laboratory based study. SETTING: Department of Parasitology, Faculty of Medicine, University of Colombo. METHODS: Bananas brought to the department with a query of maggot infestation were examined and the presence of maggots was confirmed. Maggots were allowed to develop into adults. The larvae and the flies were identified using standard keys. RESULTS: Megaselia scalaris was identified, the larvae of which infest ripe bananas. Three generations of M scalaris were reared using ripe bananas as the only source of food. Two other banana specimens yielded larvae that eventually grew into adult flies of Bactrocera species. CONCLUSIONS: In addition to Bactrocera spp. larvae of which are known pests in bananas, M scalaris larvae were detected as pests for the first time. We demonstrated that M scalaris can complete its life-cycle depending on ripe bananas as the only source of food. The vast consumption of bananas and the potential of M scalaris to cause intestinal and wound myiasis in humans make these findings medically important.