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1.
Stud Mycol ; 87: 1-41, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28373739

RESUMEN

Species of Elsinoë are phytopathogens causing scab and spot anthracnose on many plants, including some economically important crops such as avocado, citrus, grapevines, and ornamentals such as poinsettias, field crops and woody hosts. Disease symptoms are often easily recognisable, and referred to as signature-bearing diseases, for the cork-like appearance of older infected tissues with scab-like appearance. In some Elsinoë-host associations the resulting symptoms are better described as spot anthracnose. Additionally the infected plants may also show mild to severe distortions of infected organs. Isolation of Elsinoë in pure culture can be very challenging and examination of specimens collected in the field is often frustrating because of the lack of fertile structures. Current criteria for species recognition and host specificity in Elsinoë are unclear due to overlapping morphological characteristics, and the lack of molecular and pathogenicity data. In the present study we revised the taxonomy of Elsinoë based on DNA sequence and morphological data derived from 119 isolates, representing 67 host genera from 17 countries, including 64 ex-type cultures. Combined analyses of ITS, LSU, rpb2 and TEF1-α DNA sequence data were used to reconstruct the backbone phylogeny of the genus Elsinoë. Based on the single nomenclature for fungi, 26 new combinations are proposed in Elsinoë for species that were originally described in Sphaceloma. A total of 13 species are epitypified with notes on their taxonomy and phylogeny. A further eight new species are introduced, leading to a total of 75 Elsinoë species supported by molecular data in the present study. For the most part species of Elsinoë appear to be host specific, although the majority of the species treated are known only from a few isolates, and further collections and pathogenicity studies will be required to reconfirm this conclusion.

2.
Lupus ; 26(4): 426-430, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27821514

RESUMEN

Objective To determine the overall prevalence of autoimmune hemolytic anemia (AIHA), and to compare clinical and laboratory features in a large population of children and adult lupus patients at diagnosis. Methods This retrospective study evaluated the medical charts of 336 childhood-onset systemic lupus erythematosus (cSLE) and 1830 adult SLE (aSLE) patients followed in the same tertiary hospital. Demographic data, clinical features and disease activity were recorded. AIHA was defined according to the presence of anemia (hemoglobin <10 g/dL) and evidence of hemolysis (reticulocytosis and positive direct antiglobulin test (DAT)/Coombs test) at SLE diagnosis. Evans syndrome (ES) was defined by the combination of immune thrombocytopenia (platelet count <100,000/mm3) and AIHA. Results The frequency of AIHA at diagnosis was significantly higher in cSLE patients compared to aSLE (49/336 (14%) vs 49/1830 (3%), p = 0.0001), with similar frequency of ES (3/336 (0.9%) vs 10/1830 (0.5%), p = 0.438). The median of hemoglobin levels was reduced in cSLE vs aSLE patients (8.3 (2.2-10) vs 9.5 (6.6-10) g/dL, p = 0.002) with a higher frequency of multiple hemorrhagic manifestations (41% vs 7%, p = 0.041) and erythrocyte transfusion due to bleeding (24% vs 5%, p = 0.025). cSLE patients also had more often constitutional involvement (84% vs 31%, p < 0.001), fever (65% vs 26%, p < 0.001), weight loss > 2 kg (39% vs 6%, p < 0.001), reticuloendothelial manifestations (48% vs 8%, p < 0.001), hepatomegaly (25% vs 2%, p < 0.001) and splenomegaly (21% vs 2%, p = 0.004). Other major organ involvements were common but with similar frequencies in cSLE and aSLE ( p > 0.05). Median systemic lupus erythematosus disease activity index 2000 (SLEDAI-2 K) was comparable in cSLE and aSLE (p = 0.161). Conclusions We identified that AIHA was not a common condition in cSLE and aSLE, with distinct features characterized by a higher prevalence/severity in children and concomitant constitutional symptoms in the majority of them.


Asunto(s)
Anemia Hemolítica Autoinmune/diagnóstico , Lupus Eritematoso Sistémico/diagnóstico , Trombocitopenia/diagnóstico , Adolescente , Adulto , Factores de Edad , Edad de Inicio , Anciano , Anemia Hemolítica Autoinmune/tratamiento farmacológico , Anemia Hemolítica Autoinmune/patología , Niño , Preescolar , Femenino , Humanos , Inmunosupresores/uso terapéutico , Lupus Eritematoso Sistémico/patología , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Trombocitopenia/patología , Adulto Joven
3.
J Appl Microbiol ; 120(2): 388-401, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26541097

RESUMEN

AIMS: The goals of the present study were to identify, to analyse the phylogenetic relations and to evaluate the genetic variability in Diaporthe endophytic isolates from common bean. METHODS AND RESULTS: Diaporthe sp., D. infecunda and D. phaseolorum strains were identified using multilocus phylogeny (rDNA ITS region; EF1-α, ß-tubulin, and calmodulin genes). IRAP (Inter-Retrotransposon Amplified Polymorphism) and REMAP (Retrotransposon-Microsatellite Amplified Polymorphism) molecular markers reveal the existence of high genetic variability, especially among D. infecunda isolates. CONCLUSIONS: It was concluded that the multilocus phylogenetic approach was more effective than individual analysis of ITS sequences, in identifying the isolates to species level, and that IRAP and REMAP markers can be used for studying the genetic variability in the genus Diaporthe particularly at the intraspecific level. SIGNIFICANCE AND IMPACT OF THE STUDY: The combined use of molecular tools such as multilocus phylogenetic approach and molecular markers, as performed in this study, is the best way to distinguish endophytic strains of Diaporthe isolated from common bean (Phaseolus vulgaris L.).


Asunto(s)
Ascomicetos/genética , Endófitos/genética , Variación Genética , Phaseolus/microbiología , Ascomicetos/clasificación , Ascomicetos/aislamiento & purificación , Brasil , Endófitos/clasificación , Endófitos/aislamiento & purificación , Repeticiones de Microsatélite , Datos de Secuencia Molecular , Filogenia , Polimorfismo Genético , Tubulina (Proteína)/genética
4.
Persoonia ; 37: 142-172, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-28232763

RESUMEN

Although the genus Pseudocercospora has a worldwide distribution, it is especially diverse in tropical and subtropical countries. Species of this genus are associated with a wide range of plant species, including several economically relevant hosts. Preliminary studies of cercosporoid fungi from Brazil allocated most taxa to Cercospora, but with the progressive refinement of the taxonomy of cercosporoid fungi, many species were relocated to or described in Pseudocercospora. Initially, species identification relied mostly on morphological features, and thus no cultures were preserved for later phylogenetic comparisons. In this study, a total of 27 Pseudocercospora spp. were collected, cultured, and subjected to a multigene analysis. Four genomic regions (LSU, ITS, tef1 and actA) were amplified and sequenced. A multigene Bayesian analysis was performed on the combined ITS, actA and tef1 sequence alignment. Our results based on DNA phylogeny, integrated with ecology, morphology and cultural characteristics revealed a rich diversity of Pseudocercospora species in Brazil. Twelve taxa were newly described, namely P. aeschynomenicola, P. diplusodonii, P. emmotunicola, P. manihotii, P. perae, P. planaltinensis, P. pothomorphes, P. sennae-multijugae, P. solani-pseudocapsicicola, P. vassobiae, P. wulffiae and P. xylopiae. Additionally, eight epitype specimens were designated, three species newly reported, and several new host records linked to known Pseudocercospora spp.

5.
Stud Mycol ; 80: 89-130, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26955192

RESUMEN

Species in the genus Calonectria (Hypocreales) represent an important group of plant pathogenic fungi that cause serious losses to plant crops in tropical and subtropical climates. Calonectria leaf blight is currently one of the main impediments to Eucalyptus cultivation in Brazil, and various species of Calonectria have been associated with this disease. Since most previous identifications were solely based on morphological characters, much of the published literature needs to be re-evaluated. The aim of this study was thus to identify and determine the phylogenetic relationships among species that occur in the Eucalyptus growing regions of Brazil by using partial sequences of the ß-tubulin, calmodulin, translation elongation factor 1-α and histone H3 gene regions. Based on extensive collections from soil and infected eucalypt leaf samples from plantations, phylogenetic inference revealed the Ca. pteridis complex to be the most common species complex present in Eucalyptus plantations in Brazil. By elucidating taxa in the Ca. pteridis, Ca. cylindrospora and Ca. candelabra species complexes, 20 novel Calonectria species were identified, and a new name in Calonectria provided for Cylindrocladium macrosporum as Ca. pseudopteridis.

6.
Plant Dis ; 99(1): 157, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30699753

RESUMEN

Anthracnose or ripe rot of blueberry (Vaccinium spp.) is caused predominantly by Colletotrichum fioriniae, which belongs to the C. acutatum complex since it has cylindrical conidia with both ends acute (2). In May 2013, an isolate typical of the C. boninense complex (cylindrical conidia with both ends rounded) (1) was obtained from leaves of southern highbush blueberry seedlings in a nursery located in the municipality of Pelotas, Rio Grande do Sul, Brazil. The symptoms initially appear as circular, necrotic lesions 10 to 30 mm in diameter. At high humidity, lesions expand rapidly to cover the entire foliar surface, leading to severe defoliation of the seedlings. This disease occurred in 100% of the seedlings, causing serious losses in the nursery. A single-conidium culture was obtained on potato-dextrose-agar (PDA) medium followed by morphological and molecular characterization. This culture was deposited at the culture collection of the Universidade Federal de Viçosa, Brazil (Accession No. COAD 1741). Conidia were cylindrical, aseptate, hyaline, rounded at both ends, and 11 to 16 µm (µ = 13) long and 5 to 6 µm (µ = 5.5) wide (n = 100). For the molecular characterization, sequences of the internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and ß-tubulin 2 (ßt) regions were obtained and deposited in GenBank (KM055653 to KM055655). A search of the Q-bank Fungi database using the ITS, ßt, and GAPDH sequences retrieved C. karstii with 100, 99, and 100% identities, respectively. Based on morphological and molecular data, the fungus was identified as C. karstii. To verify pathogenicity, 20 leaves from the upper branches of 1-m tall blueberry seedlings were inoculated with 6-mm-diameter plugs from a 7-day-old culture. PDA plugs were placed on the leaves of seedlings to serve as the control. Initially, seedlings were maintained at 25 ± 2°C in the dark. Thereafter, seedlings were covered with plastic bags and transferred to a greenhouse. Anthracnose symptoms on the leaves were observed at 5 days after inoculation. Seedlings from the control treatment remained symptomless. The fungus was re-isolated from the necrotic lesions, confirming Koch's postulates. C. karstii has a wide host range and in Brazil has been previously reported on Bombax aquaticum, Carica papaya, Eugenia uniflora, Malus domestica, and Mangifera indica (1,3,4). To the best of our knowledge, this is the first report of C. karstii causing anthracnose on the leaves of blueberry seedlings in Brazil or worldwide. Due to the high disease severity and intense defoliation of blueberry seedlings, this pathogen represents a new threat for nurseries. Therefore, control strategies should be investigated for this disease. References: (1) U. Damm et al. Stud. Mycol. 73:1, 2012. (2) U. Damm et al. Stud. Mycol. 73:37, 2012. (3) Lima et al. Plant Dis. 97:1248, 2014. (4) Velho et al. Plant Dis. 98:157, 2014.

7.
Persoonia ; 35: 230-41, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26823634

RESUMEN

Members of the Asterinaceae and Parmulariaceae are obligate biotrophic fungi with a pantropical distribution that grow in direct association with living plant tissues and produce external ascomata and bitunicate asci. These fungi are poorly known, with limited information about their taxonomic position in the Dothideomycetes. Much of what is known is conjectural and based on observation of morphological characters. An assessment of the phylogenetic position of the Asterinaceae and Parmulariaceae is provided based on a phylogenetic analysis of the nrDNA operon (ITS) and the large subunit rDNA (LSU) sequence data obtained from fresh material of selected species collected in Brazil. Three key species were included and epitypified, namely Asterina melastomatis, which is the type species for the type genus of the Asterinaceae; Prillieuxina baccharidincola (Asterinaceae); and Parmularia styracis, which is the type species for the type genus of the Parmulariaceae. An LSU rDNA phylogenetic analysis was performed indicating the correct phylogenetic placement of the Asterinales within the Dothideomycetes. From this initial analysis it is clear that the Parmulariaceae as currently circumscribed is polyphyletic, and that the Asterinaceae and Parmulariaceae are related, which justifies the maintenance of the order Asterinales. Asterotexis cucurbitacearum is recognised as distinct from other Dothideomycetes and placed in the newly proposed family and order (Asterotexiaceae, Asterotexiales), while the higher order phylogeny of Inocyclus angularis remains unresolved. Additionally, Lembosia abaxialis is introduced as a novel species and the phylogenetic placement of the genera Batistinula and Prillieuxina is clarified.

8.
Plant Dis ; 98(9): 1277, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30699669

RESUMEN

Pineapple (Ananas comosus L. Merril.) is the main plant of the Bromeliaceae, cultivated economically for the fruits' appealing flavor and a refreshing sugar-acid balance. In 2013, fruits with no initially visible symptoms began to show a postharvest rot after 3 days in a market in the municipality of Viçosa, Minas Gerais, Brazil. The rot can rarely be detected from the outside of the fruit, but a longitudinal section allows observation of extension of the affected area toward the center of the fruit. The symptoms initially appear as a dark brown to black rot on surface of the fruits, which gradually enlarges in size, leading to increased rot and disposal of infected fruits. Until now, this disease occurred sporadically and caused small losses. A fungus was isolated from rot observed in fruits from cultivar Pérola and a single-spore culture was deposited in the culture collection of the Universidade Federal de Viçosa (Accession No. COAD 1588). After 7 days of incubation at 25°C, the strain displayed radial growth and gray-white to black colonies. Microscopic observations revealed brown to light brown conidiophores present singly or in groups. The septate, simple or rarely branched conidiophores are straight or curved, up to 245 µm long and 5 µm wide, and some have a geniculate growth pattern near the apex. The conidia are ellipsoidal or barrel-shaped and 22 to 25 µm long and 10 to 12.5 µm wide. The median septum appears as a black band and the cells at each end of the conidia are pale, whereas the intermediate cells are brown or dark brown. Based on morphological characteristics, the fungus was identified as Curvularia eragrostidis (4). To confirm this identification, DNA was extracted and sequences of the internal transcribed spacer (ITS), 28S and 18S rDNA regions were obtained and deposited in GenBank (Accession Nos. KJ541818 to KJ541820). The sequence of the ITS region exhibited 99% identity over 530 bp with other C. eragrostidis sequence in GenBank (JN943449) and Bayesian inference analysis placed our isolate in the same clade with others C. eragrostidis (study S15670 deposited in TreeBASE). Koch's postulates were conducted by inoculating six fruits of pineapple previously disinfected with 2% sodium hypochlorite and washed in sterile distilled water. For inoculation, the isolate was grown in potato dextrose agar (PDA) for 15 days at 25°C. Six millimeter diameter disks were removed from the surface of fruits with a sterile cork borer and replaced with PDA disks containing mycelia from the margins of the culture. An agar plug was deposited in three control fruits and all fruits were maintained at 25°C in plastic trays. Inoculated fruits showed symptoms 7 days after inoculation that were similar to those initially observed in the infected fruits, while control fruits showed no symptoms. C. eragrostidis is a cosmopolitan pathogen that infects hosts from several botanical families (2,4). In Brazil, this fungus causes leaf spot on A. comosus (3) and also infects Allium sativum, Dioscorea alata, D. cayenensis, Oryza sativa, Sorghum bicolor, Vigna unguiculata, and Zea mays (1). To our knowledge, this is the first report of C. eragrostidis causing postharvest rot disease in pineapple in Brazil. Because invasion of the fungus can occur through minute fractures, fruits should be carefully handled to avoid mechanical damage. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases , 18 February 2014. (2) D. S. Manamgoda et al. Fungal Divers. 51:3, 2011. (3) J. J. Ponte et al. Fitopatologia 10:21, 1975. (4) A. Sivanesan. Mycological Papers 158:113, 1987.

9.
Plant Dis ; 98(11): 1587, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30699835

RESUMEN

Coffea canephora (conilon coffee) represents approximately 30% of the coffee marketed worldwide. The state of Espírito Santo is the largest conilon coffee-producing state in Brazil. In 2013 and 2014, leaves with a leaf spot were observed on most of the conilon coffee seedlings in a commercial nursery in Laranja da Terra, Espírito Santo, Brazil. The infected leaves were deposited in the VIC Herbarium (VIC 42482) and a pure single-spore culture of the pathogen was deposited in the culture collection of the Universidade Federal de Viçosa (Accession No. COAD 1729). The initial symptoms were circular, brown to dark brown lesions with yellow margins occurring on both leaf surfaces. In high humidity, concentric rings formed and the lesions expanded rapidly to reach up to 30 mm in diameter, and later became dark brown with a grayish center. Black sporodochia with white, and marginal mycelial tuffs bearing black spore masses were observed in the older lesions. These symptoms were consistent with those of Myrothecium leaf spot reported on Coffea spp. (3). Microscopic observation revealed aseptate, hyaline, and cylindrical conidia, rounded at both ends, greenish to black in mass, and 5 to 6 µm long and 1 to 2 µm wide. The symptoms and morphological characteristics described above matched the description of Myrothecium roridum Tode (4). To confirm this identification, DNA was extracted using a Wizard Genomic DNA Purification Kit and the sequence of an internal transcribed spacer (ITS) region was obtained and deposited in GenBank (Accession No. KJ815095). The sequence of the ITS region exhibited 100% identity over 561 bp with another M. roridum sequence in GenBank (JF343832). To verify the pathogenicity of the fungus, healthy leaves of the C. canephora clones 12v and 14 (four seedlings each) were wounded superficially with a sterilized needle and inoculated by spraying them with a suspension of M. roridum conidia (106 conidia ml-1). The seedlings were covered with plastic bags and incubated in a growth chamber at 25°C under a photoperiod of 12 h light/12 h dark for 5 days. The control seedlings were sprayed with distilled water and incubated similarly. Fifteen days after inoculation, symptoms in all inoculated seedlings were consistent with those initially observed on the naturally infected seedlings, whereas the controls remained healthy. Re-isolation and identification confirmed Koch's postulates. M. roridum has a wide host range, and symptoms were similar to those reported in other hosts of the pathogen in Brazil (2,3). There is only one report of M. roridum on C. canephora in Colombia (1); however, this pathogen was previously reported on C. arabica in Brazil, Colombia, Costa Rica, Guatemala, India, Indonesia, Puerto Rico, and the Virgin Islands (1,3). To our knowledge, this is the first report of a leaf spot caused by M. roridum on conilon coffee in Brazil. The cultivation of conilon coffee is increasing and the reported leaf spot disease affects the quality of the seedlings in nurseries. It is therefore important to conduct a thorough study of management strategies for this disease. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab. ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases , 27 May 2014. (2) A. M. Quezado Duval et al. Braz. J. Microbiol. 41:246, 2010. (3) S. F. Silveira et al. Fitopatol. Bras. 32:440, 2007. (4) M. Tulloch. Mycol. Pap. No. 130. CMI, Wallingford, UK, 1972.

10.
Plant Dis ; 98(10): 1437, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30703977

RESUMEN

Anthracnose is major disease of pepper (Capsicum annum) in the tropics and causes severe damage both in the field and postharvest. In Brazil, this disease is caused by Colletotrichum acutatum, C. boninense, C. capsici, C. coccodes, and C. gloeosporioides, where the first species is responsible for 70% of all occurrences (3). Recently, C. acutatum has been considered a species complex (1); thus, the aim of this study was to verify the etiology of anthracnose on peppers using a morphological and molecular approaches. In 2011, pepper fruits with typical symptoms of anthracnose (dark, sunken spots with concentric rings of orange conidial masses) were collected in Viçosa, Minas Gerais, Brazil. A single spore isolate was obtained on potato dextrose agar (PDA), and the derived culture was deposited in the Coleção de Culturas de Fungos Fitopatogênicos "Prof. Maria Menezes" (code CMM-4200). The upper side colonies on PDA were gray, cotton-like, and pale gray to pale orange. Conidia were hyaline, aseptate, smooth, straight, cylindrical with round ends or occasionally with end ± acute, 12.5 to 17 µm long and 3.5 to 4 µm wide on synthetic nutrient deficient agar. The isolate was morphologically typical of species belonging to the C. acutatum complex. Molecular identification of the pathogen was carried out and sequences of the regions internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and ß-tubulin (ßt) were obtained and deposited in GenBank (Accession Nos. KJ541821 to KJ541823). A search in the Q-bank fungi database using the ITS, ßt, and GAPDH sequences retrieved C. scovillei with 100% identity for all three genes. This pathogen was previously reported in Capsicum spp. only in Thailand, Indonesia, and Japan (1,2). To confirm pathogenicity, drops with 105 spores/ml were deposited in 10 artificially wounded fruits (cv. Itapuã 501 and Melina). In control fruits, drops of sterilized water were deposited onto wounds. The fruits were covered for one day with a transparent plastic bag with moisture supplied by a wet filter paper. The fruits were detached and mature. The bags were removed, and the fruits were incubated for 10 days in a growth chamber at 25°C with a photoperiod of 12 h. After 4 days, gray-brown to black sunken spots with concentric rings were observed on 100% of the wounded fruits that had been inoculated. No disease was observed on the control fruits. The fungus C. scovillei was successfully re-isolated from symptomatic fruits to fulfill Koch's postulates. To our knowledge, this is the first report of anthracnose on pepper fruit caused by C. scovillei in Brazil. Due to the diversity of species that cause anthracnose in Capsicum, future studies using morphological and molecular tools are essential for the correct identification of Colletotrichum spp. on pepper in Brazil. References: (1) U. Damm et al. Stud. Mycol. 73:37, 2012. (2) T. Kanto et al. J. Gen. Plant. Pathol. 80:73, 2014. (3) M. J. Z. Pereira et al. Hortic. Bras. 29:569, 2011.

11.
Plant Dis ; 97(9): 1255, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30722441

RESUMEN

In Brazil, dieback and necrosis of leaves and berries of coffee trees (Coffea arabica and C. canephora) are common symptoms of anthracnose disease caused by Colletotrichum gloeosporioides (Penz.) Sacc. In April 2010, these symptoms were observed in 100% of the plants from different coffee plantations in the Brazilian states of Espírito Santo and Bahia. Ten isolates were obtained from symptomatic leaves and berries from these areas. Of the 10 isolates, one had distinct conidial morphology with hyaline and ellipsoid conidia measuring 10 to 16 × 5.0 to 7.5 µm and melanized irregular or spatulated-shaped appressoria measuring 7.5 to 11.0 × 5.5 to 8.5 µm, formed either solitary or concatenated, which concurred with the conidia description of Colletotrichum boninense. In order to confirm the identity of this isolate, the internal transcribed spacer (ITS) rRNA region and the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene were sequenced (GenBank Accession Nos. JF683320 and JF331654, respectively) and compared to sequences from a database of C. boninense, confirming that the isolate was definitely C. boninense sensu lato, since it was exactly identical to other sequences in a large clade of isolates. To verify the pathogenicity of C. boninense in coffee and to compare the symptoms with those caused by C. gloeosporioides, leaves and berries were inoculated with the isolate of C. boninense and one representative isolate of C. gloeosporioides, both expressing the GFP (green fluorescent protein) gene. The isolates were grown for 7 days on potato dextrose agar and a conidial suspension (106 conidia × ml-1) was used to inoculate the organs, wounded and non-wounded, at different stages of development. In non-wounded organs, the conidial suspension was inoculated on the surface, and in leaves and berries used as control, the suspensions were substituted for sterile water. Leaves and berries were wounded with a sterilized needle and inoculated with 20 and 10 µl of the conidial suspension, respectively. Inoculated materials were incubated at 25°C and 100% relative humidity. The experiment was performed twice and evaluated daily for a week. No symptoms were observed on the control and non-wounded organs, while wounded organs exhibited typical anthracnose symptoms for both species. In berries, C. gloeosporioides consistently caused more severe symptoms at a faster rate than C. boninense. Both fungi caused necrosis in young but not old leaves. Typical acervuli were observed on the lesions and the fungus was successfully recovered from the inoculated tissues, which was confirmed by fluorescence microscopy, fulfilling Koch's Postulates. C. boninense has been identified as a pathogen causing anthracnose in a range of hosts worldwide. However, in Brazil, it has only been reported in pepper (Capsicum annuum) (3), passion fruit (Passiflora) (4), Hippeastrum (1) and in the medicinal plant Maytenus ilicifolia (2). To our knowledge, this is the first report of C. boninense associated with anthracnose of coffee trees in Brazil. Since the symptoms are similar to those caused by C. gloeosporioides, it can be stated that both species are associated with this disease in commercial coffee plantations in Brazil. Therefore, control strategies should consider the occurrence of C. boninense. References: (1) D. F. Farr et al. Mycol. Res. 110:1395, 2006. (2) S. A. Pileggi et al. Can. J. Microbiol. 55:1076, 2009. (3) H. J. Tozze et al. Plant Dis. 93:106, 2009. (4) H. J. Tozze et al. Australas. Plant Dis. Notes 5:70, 2010.

12.
Plant Dis ; 97(9): 1257, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30722451

RESUMEN

Yucca filamentosa L. (Agavaceae), commonly known as Adam's needle, is known in Brazil as "agulha-de-adão." It is an ornamental garden plant with medicinal properties (4). In 2010, 100% of Y. filamentosa seedlings and plants were observed with a severe leaf spot disease in two ornamental nurseries located in the municipality of Viçosa, Minas Gerais, Brazil. Initially, lesions were dark brown, elliptical, and scattered, and later became grayish at the center with a reddish brown margin, irregular and coalescent. Infected leaf samples were deposited in the herbarium at the Universidade Federal de Viçosa (Accession Nos. VIC32054 and VIC32055). A fungus was isolated from the leaf spots and single-spore pure cultures were obtained on potato dextrose agar (PDA). The sporulating single-spore cultures were deposited at the Coleção de Culturas de Fungos Fitopatogênicos "Prof. Maria Menezes" (CMM 1843 and CMM 1844). On the leaf, the fungus produced pycnidial conidiomata that were scattered or gregarious, usually epiphyllous, immersed, dark brown, unilocular, subglobose, and 95 to 158 × 108 to 175 µm, with a minute, subcircular ostiole. Conidiogenous cells were blastic, hyaline, conoidal, or short cylindrical. Conidia were aseptate, hyaline, smooth walled, coarsely granular, broadly ellipsoidal to subglobose or obovate, usually broadly rounded at both ends, occasionally truncate at the base or indented slightly at the apex, and 7.5 to 13.5 × 6 to 10 µm. Conidia were also surrounded by a slime layer, usually with a hyaline, flexuous, narrowly conoidal or cylindrical, mucilaginous apical appendage that was 10 to 16 µm long. Spermatia were hyaline, dumbbell shaped to cylindrical, both ends bluntly rounded, and 3 to 5 × 1 to 1.5 µm. These characteristics matched well with the description of Phyllosticta yuccae Bissett (1). To confirm this identification, DNA was extracted using a Wizard Genomic DNA Purification Kit and amplified using primers ITS1 and ITS4 (2) for the ITS region (GenBank Accession Nos. JX227945 and JX227946) and EF1-F and EF2-R (3) for the TEF-1α (JX227947 and JX227948). The sequencing was performed by Macrogen, South Korea. The ITS sequence matched sequence No. JN692541, P. yuccae, with 100% identity. To confirm Koch's postulates, four leaves of Y. filamentosa (five plants) were inoculated with 6-mm-diameter plugs from a 7-day-old culture growing on PDA. The leaves were covered with plastic sack and plants were maintained at 25°C. In a similar manner, fungus-free PDA plugs were placed on five control plants. Symptoms were consistently similar to those initially observed in the nurseries and all plants developed leaf spots by 15 days after inoculation. P. yuccae was successfully reisolated from the symptomatic tissue and control plants remained symptomless. P. yuccae has been previously reported in Canada, the Dominican Republic, Guatemala, Iran, and the United States of America. To our knowledge, this is the first report of P. yuccae causing disease in Y. filamentosa in Brazil and it may become a serious problem for the nurseries, due to the severity of the disease and the lack of chemical products to control this pathogen. References: (1) J. Bissett. Can. J. Bot. 64:1720, 1986. (2) M. A. Innis et al. PCR Protocols: A guide to methods and applications. Academic Press, 1990. (3) Jacobs et al. Mycol. Res. 108:411, 2004. (4) H. Lorenzi and H. M. Souza. Plantas Ornamentais no Brasil. Instituto Plantarum, 2001.

13.
Plant Dis ; 97(6): 847, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30722636

RESUMEN

Gladiolus (Iridaceae) is a popular bulbous plant grown worldwide as an ornamental garden plant or cut flower due to its attractive color, size, and flower shape. In April 2012, leaf spots were observed on plants of Gladiolus grandiflorus varieties T-704 and Amsterdam growing in a production area of cut flowers located in the city of Viçosa, Minas Gerais. The oval to round leaf spots were brown with a dark border surrounded by a halo of yellow tissue. Infected leaf samples were deposited in the herbarium at the Universidade Federal de Viçosa (VIC31897). A fungus was isolated from the leaf spots and a single-spore pure culture was initiated and grown on corn meal carrot agar (CCA) medium in petri dishes incubated at 25°C under a 12-h photoperiod for 4 weeks. A sporulating single-spore culture was deposited at the Coleção de Culturas de fungos fitopatogênicos "Prof. Maria Menezes" (UFRPE, Brazil) code CMM 4055. On CCA medium, the fungal isolate initially appeared white, becoming dark after 14 days. Thirty conidia and conidiophores were measured for identification to species. The septate, smooth to pale brown conidiophores were present singly or in groups. The simple, straight or flexuous conidiophores were 42.5 to 82.5 × 3.5 to 7.5 µm and some had a geniculate growth pattern. The majority of conidia were curved at the third (central) cell from the base, which was usually enlarged compared to the end cells. The cells at each end of the 3-distoseptate conidia were pale brown, the intermediate cell brown or dark brown, and the third (central) cell was often the darkest. The basal cell had a protuberant hilum. Conidia were smooth and 20.0 to 33.5 × 10 to 17.5 µm. These characteristics matched well with the description of Curvularia gladioli (1). To confirm this identification, DNA was extracted using a Wizard Genomic DNA Purification Kit and the internal transcribed spacer region (ITS) of rDNA was amplified using ITS1 and ITS4 primers and the partial 28S rDNA region using primers LR0R and LR5. The sequences were deposited in GenBank as accession nos. JX995106 and JX995107, respectively. The ITS sequence matched sequence AF071337, C. gladioli, with 100% identity. This pathogen was first identified as C. lunata, but based on the characteristic of the hilum, spore size, and pathogenicity testing, the fungus was renamed C. trifolii f. sp. gladioli (3). Due to the explicit curvature of the conidia at the third cell and molecular data, the fungus was reclassified as C. gladioli (1,2). To confirm Koch's postulates, 1-month-old healthy plants of G. grandiflorus var. T-704 and Amsterdam (five plants each) were inoculated with a conidial suspension (2 × 104 conidia mL-1) by spraying the foliage and then placed on a growth chamber at 25°C. The control plants were sprayed with distilled water. Symptoms were consistent with those initially observed and all plants developed leaf spots by 4 days post-inoculation. C. gladioli was consistently recovered from the symptomatic tissue and control plants remained symptomless. To our knowledge, this is the first report of C. gladioli causing leaf spot on G. grandiflorus in Brazil. Due to a lack of chemical fungicides for management of this pathogen, further studies to evaluate the susceptibility of the main varieties of gladiolus grown in Brazil to C. gladioli may be necessary. References: (1) G. H. Boerema and M. E. C. Hamers. Neth. J. Plant Pathol. 95:1, 1989. (2) D. S. Manamgoda et al. Fungal Divers. 56:131, 2012. (3) J. A. Parmelee. Mycologia 48:558, 1956.

14.
Plant Dis ; 96(11): 1697, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30727493

RESUMEN

Physic nut (Jatropha curcas L.; Euphorbiaeae) has become important in Brazil due to its potential as a feedstock for biodiesel production. In October 2010, during routine monitoring of fields in the state of Piauí, several plants were observed with symptoms of collar and root rot. Initially, plants appeared withered and chlorotic, and later became defoliated. Roots and collars of affected plants also appeared rotten with black fungal structures directly observed. Symptomatic tissue fragments of 5 mm diameter were washed with 70% ethanol, 1% sodium hypochlorite, and sterilized water, before being placed in petri dishes containing potato dextrose agar (PDA) and incubated at 25°C. Pure cultures were then obtained by single-spore isolation. The fungus isolated was grown on plates containing 2% water agar overlaid with sterilized corn straw or pine twigs and incubated at 25°C under a photoperiod of 12 h for 4 weeks to induce the formation of fruiting bodies. Thirty measurements of all of the relevant morphological characters were made using a light microscope for the identification of the species. On PDA, isolates initially appeared white and became dark after 7 days. The aerial mycelia formed chains of zero- to one-septate arthroconidia, oblong to globose, initially hyaline that became brown and with a thick wall with age. The dimensions of arthroconidia were 4 to 12 × 2.5 to 8 µm. The formation of pycnidia was observed on the plates with corn straw and pines twigs. These were dark, with a globose base up to 250 µm and a neck up to 810 µm. Conidiogenous cells were holoblastic, lageniform to ampulliform, hyaline, and 6 to 10 × 1.5 to 2.5 µm. Conidia were hyaline, ellipsoid to nearly fusiform, and 8 to 12 × 4 to 5 µm. Septate and dark conidia were not observed. DNA was extracted from one isolate following Wizard Genomic DNA Purification Kit procedures and amplified using primers ITS1 and ITS4. Products were directly sequencing by Macrogen, Korea. The 856-bp sequence obtained was deposited in GenBank (Accession No. JQ927342). The sequence was 99% similar to Neoscytalidium dimidiatum (Penz.) Crous & Slippers, further supporting the identification by morphology. Pathogenicity tests were conducted by using 6 mm disks removed from the outer bark of the collar region of healthy plants using a sterile cork borer, and 6-mm diameter plugs were placed in each wound. Five plants were inoculated with the isolate and five plants inoculated with an isolate-free agar plug. Below these, pieces of moistened cotton were placed and covered with Parafilm. After 60 days, all inoculated plants reproduced the symptoms observed in the field, and the pathogen was successfully reisolated. All non-inoculated plants remained healthy. The genus Neoscytalidium includes species having Scytalidium-like synanamorphs in the aerial mycelia and Fusicoccum-like conidia in the pycnidia (1). Currently, this species is reported to cause diseases in fig, mango, and orange (2,3). To our knowledge, this is the first report of collar and rot root caused by N. dimidiatum in J. curcas and of this fungus in Brazil. It seems likely the disease exists in areas beyond Piauí and could cause important losses for biodiesel production. References: (1) P. W. Crous et al. Stud. Mycol. 55:235, 2006. (2) G. Polizzi et al. Plant Dis. 93:1215, 2009. (3) J. D. Ray et al. Austral. Plant Dis. Notes 5:48, 2010.

15.
Plant Dis ; 96(11): 1702, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30727504

RESUMEN

Pfaffia glomerata (Spreng) Pedersen (Amaranthaceae) and other species in this genus, popularly known as "Brazilian ginseng," have been marketed and used for many years in folk medicine for the treatment of various diseases (1). In January 2012, samples of P. glomerata with leaf spots were collected in the city of Viçosa, state of Minas Gerais, Brazil. Two samples were deposited in the herbarium at the Universidade Federal de Viçosa (VIC31849 and VIC31851). The diseased leaves were examined using a stereomicroscope (75×). The fungal structures were scraped with a scalpel from the plant surface and mounted in lactophenol. Thirty measurements of all of the relevant morphological characters were obtained using light microscopy for the identification of the species. To confirm the identification, fungal DNA from single-spore pure culture was isolated from the diseased leaves on PDA, and the DNA was amplified using primers ITS1 and ITS4 for the ITS region (GenBank Accession No. JQ990331) and LR0R and LR5 for partial 28S rDNA (Accession No. JQ990330). Sequencing was performed by Macrogen, Korea. The symptoms observed were leaf spots, subcircular, usually up to 6 mm diameter, initially yellowish becoming brown to reddish, margin indefinite, with the formation of fungal structures, hypophyllous, white, scattered, or grouped. Conidiophores were very numerous in dense subsynnematal fascicles, moderately brown at the base but for most of the length subhyaline, 42.5 to 350 × 2.5 to 3.5 µm, showing conidial scars. Conidia formed singly, 22.5 to 77.5 × 5 to 6 µm, hyaline, hilum slightly thickened, and refractive. These characteristics show that the fungus found on P. glomerata matched well with the description of Cercosporella pfaffiae (2). Koch's postulates were fulfilled by inoculation of 6-mm-diameter PDA plugs with the isolate mycelia on leaves of P. glomerata. Six plants were inoculated with the isolate and six plants were inoculated with an isolate-free agar plug. Inoculated plants were maintained in a moist chamber for 24 hours and subsequently in a greenhouse at 26°C. Leaf spot was observed in inoculated plants 15 days after inoculation, and symptoms were similar to those in the field. All non-inoculated plants remained healthy. A Megablast search of the NCBI GenBank nucleotide sequence database using the ITS sequence retrieved C. virgaureae as the closest match [GenBank GU214658; Identity = 458/476 (96%), Gaps = 2/476 (0%)]. To confirm the identification, Bayesian inference analyses were employed, and the tree was deposited in TreeBASE (Study S12680). The analysis placed our isolate in the same clade with the type species of Cercosporella. Molecular studies and morphological characteristics confirm our identification. C. pfaffiae has been previously reported in P. iresinoides (H.B.K.) Spreng. in Trinidad and Gomphrena glomerata L. in Argentina (2). To our knowledge, this is the first report of C. pfaffiae causing disease in P. glomerata in Brazil and it may become a serious problem for some medicinal plant growers, due to the severity of the disease and the lack of chemical products for this pathogen. References: (1) Neto et al. J. Ethnopharmacol. 96:87, 2005. (2) U. Braun. A Monograph of Cercosporella, Ramularia and Allied Genera (Phytopathogenic Hyphomycetes). Eching bei Müchen, IHW-Verlage. Vol. 1, p. 68, 1995.

16.
Persoonia ; 26: 47-56, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22025803

RESUMEN

We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and is subject to phytosanitary legislation in the EU. This species is frequently confused with a taxon generally referred to as G. mangiferae, the presumed teleomorph of P. capitalensis, which is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts. DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S nrDNA, ITS2) and partial translation elongation factor 1-alpha (TEF1), actin and glyceraldehyde-3-phosphate dehydrogenase (GPDH) genes resolved nine clades correlating to seven known, and two apparently undescribed species. Phyllosticta citribraziliensis is newly described as an endophytic species occurring on Citrus in Brazil. An epitype is designated for P. citricarpa from material newly collected in Australia, which is distinct from P. citriasiana, presently only known on C. maxima from Asia. Phyllosticta bifrenariae is newly described for a species causing leaf and bulb spots on Bifrenaria harrisoniae (Orchidaceae) in Brazil. It is morphologically distinct from P. capitalensis, which was originally described from Stanhopea (Orchidaceae) in Brazil; an epitype is designated here. Guignardia mangiferae, which was originally described from Mangifera indica (Anacardiaceae) in India, is distinguished from the non-pathogenic endophyte, P. brazilianiae sp. nov., which is common on M. indica in Brazil. Furthermore, a combined phylogenetic tree revealed the P. capitalensis s.l. clade to be genetically distinct from the reference isolate of G. mangiferae. Several names are available for this clade, the oldest being P. capitalensis. These results suggest that endophytic, non-pathogenic isolates occurring on a wide host range would be more correctly referred to as P. capitalensis. However, more genes need to be analysed to fully resolve the morphological variation still observed within this clade.

17.
Persoonia ; 26: 108-56, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22025808

RESUMEN

Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola taccada, Diaporthe musigena on Musa sp., Diaporthe acaciigena on Acacia retinodes, Leptoxyphium kurandae on Eucalyptus sp., Neofusicoccum grevilleae on Grevillea aurea, Phytophthora fluvialis from water in native bushland, Pseudocercospora cyathicola on Cyathea australis, and Teratosphaeria mareebensis on Eucalyptus sp. Other species include Passalora leptophlebiae on Eucalyptus leptophlebia (Brazil), Exophiala tremulae on Populus tremuloides and Dictyosporium stellatum from submerged wood (Canada), Mycosphaerella valgourgensis on Yucca sp. (France), Sclerostagonospora cycadis on Cycas revoluta (Japan), Rachicladosporium pini on Pinus monophylla (Netherlands), Mycosphaerella wachendorfiae on Wachendorfia thyrsifolia and Diaporthe rhusicola on Rhus pendulina (South Africa). Novel genera of hyphomycetes include Noosia banksiae on Banksia aemula (Australia), Utrechtiana cibiessia on Phragmites australis (Netherlands), and Funbolia dimorpha on blackened stem bark of an unidentified tree (USA). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

18.
Plant Dis ; 95(9): 1194, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30732037

RESUMEN

In Brazil, Capsicum chinense Jacq. is the predominant species of commercial hot peppers because of its popular citrus-like aroma and adaptability to different soils and climates (4). In June 2010, 30 samples of C. chinense with severe leaf spot were collected from a field in the city of Viçosa, state of Minas Gerais, Brazil. Symptoms were observed on leaves, calyxes, fruits, and stems on most of the plants found in the area. On leaves, symptoms included amphigenous lesions that were initially circular to ellipsoid, 1 to 5 mm in diameter, whitish to tan in the center, and surrounded by a dark brown or reddish purple border. Lesions coalesce and turned necrotic with age. A fungus isolated from the lesions matched well with the description of Cercospora apii Fresen. It formed erumpent stromata that were dark brown and spherical to irregular; fascicule conidiophores were clear brown or pale, straight or curved, unbranched, geniculate, 22.5 to 80 × 5 to 7.5 µm, 0 to 3 septate, subtruncate apex; and conidia were solitary, hyaline to subhyaline, filiform, base truncate, tip acute, straight to curved, 12.5 to 140 × 3.5 to 5 µm, and 0 to 11 septate (1,2). A sample was deposited in the herbarium of the Universidade Federal de Viçosa, Minas Gerais, Brazil (VIC 31415). Identity was confirmed by amplifying part of the calmodulin gene with species-specific primers CercoCal-apii and CercoCal-R (3) of fungal DNA from a single-spore culture. In amplification reaction, initial denaturation step was done at 94°C for 5 min, followed by 40 cycles of denaturation at 94°C (30 s), annealing at 56°C (30 s), and elongation at 72°C (30 s). Primers CercoCal-apii and CercoCal-R amplified a single DNA product of 176 bp, and coupled with the morphological characteristics, confirmed the identity of the fungus as Cercospora apii. To check pathogenicity, a 6-mm-diameter plug of the isolate was removed from the expanding edge of a 21-day-old culture grown on potato dextrose agar (PDA) and placed in contact with the adaxial face of the leaves of 8-week-old C. chinense grown in 2-liter plastic pots with soil substrate. Six plants, one per pot, were inoculated with the isolate and six plants were inoculated with the fungus-free PDA plug. Inoculated plants were maintained in a moist chamber for 24 h and then subsequently kept in a greenhouse at 26°C. Leaf spot was observed in all inoculated plants 15 days after inoculation and symptoms were similar to those expressed in the field. The fungus was reisolated from the inoculated plants and matched well with the description of Cercospora apii. All fungus-free PDA inoculated plants remained healthy. Cercospora apii comprises a complex of 281 morphologically indistinguishable species that can infect an extremely wide host range (2). To our knowledge, this pathogen has the potential to cause significant damage to the hot pepper industry of Brazil. References: (1) C. Chupp. A Monograph of the Fungus Cercospora. Cornell University Press, Ithaca, NY, 1954. (2) P. W. Crous and U. Braun. CBS Biodivers. Ser. 1:1, 2003. (3) M. Groenewald et al. Phytopathology 95:951, 2005. (4) S. D. Lannes et al. Sci. Hortic. 112:266, 2007.

19.
Plant Dis ; 94(11): 1378, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30743634

RESUMEN

There are more than 300 blackberry (Rubus) species worldwide. Rubus brasiliensis Mart. is a native Brazilian species found in tropical forests. In January 2009, samples of R. brasiliensis with severe leaf blight were collected from an area of rain forest in the city of São Miguel do Anta, State of Minas Gerais, Brazil. Dark spots began developing in the young leaves and progressed to necrotic spots with occasional twig dieback. From the spots, a fungus was isolated with the following morphology: acervuli that were 20 to 50.0 × 50 to 125.0 µm and hyaline amerospores that were ellipsoid and fusiform and 7.5 to 23.75 × 2.5 to 5.0 µm. On the basis of these morphological characteristics, the fungus was identified as Colletotrichum acutatum. In Brazil, C. acutatum is reported in apple, citrus, strawberry, peach, plum, nectarine, olive, medlar, and yerba-mate, but it was not reported as the causal agent of leaf blight in R. brasiliensis. A sample was deposited in the herbarium at the Universidade Federal de Viçosa, Minas Gerais, Brazil (VIC 31210). One representative isolate, OLP 571, was used for pathogenicity testing and molecular studies. Identity was confirmed by amplifying the internal transcribed spacer (ITS) regions of the ribosomal RNA with primers ITS4 (3), CaInt2 (a specific primer for C. acutatum [2]) and CgInt (a specific primer for C. gloeosporioides [1]). Isolates of C. acutatum (DAR78874 and DAR78876) and C. gloeosporioides (DAR78875) obtained from Australian olive trees were used as positive controls. The primers ITS4 and CaInt2 amplified a single DNA product of 500 bp expected for C. acutatum. OLP 571 was grown for 7 days on potato dextrose agar. Young leaves of R. brasiliensis were inoculated with a conidial suspension (106 conidia/ml) on young leaves. Inoculated plants were maintained in a moist chamber for 2 days and subsequently in a greenhouse at 25°C. Necrotic spots similar to those described were detected on young leaves 3 days after the inoculation. Control leaves, on which only water was sprayed, remained healthy. The same fungus was reisolated from the inoculated symptomatic tissues. To our knowledge, this is the first report of C. acutatum causing leaf blight in the native species of R. brasiliensis in Brazil. References: (1) P. R. Mills et al. FEMS Microbiol. Lett. 98:137, 1999. (2) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

20.
Bull Entomol Res ; 100(1): 99-103, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19366474

RESUMEN

The objective of this work was to study the effect of colony waste on the mortality of workers of Atta sexdens rubropilosa Forel colonies fed with different plant substrates. Eight nests were used; two colonies each were fed with Acalypha wilkesiana Müller.Arg, Ligustrum japonicum Thunb, Eucalyptus urophylla S.T. Blake or a mixture of the three substrates in equal proportions. Irrespective of diet, being kept with waste led to higher mortality. However, workers that were kept in contact with waste produced by colonies fed Acalypha had higher average survival rate and later death when compared with workers from the other treatments. Workers from the Eucalyptus-fed colonies had the lowest survival rate and 50% of them died within four days of exposure to Eucalyptus waste. Trichoderma viride Pers. ex Gray, a fungus garden antagonist, and the entomopathogen Aspergillus flavus Link. ex Gray were present in the colonies supplied with all plants. The largest fungus diversity was verified in the waste of colonies fed Acalypha and the mixture of Acalypha, Ligustrum and Eucalyptus. Therefore, antibiotic properties of Acalypha did not reduce contaminant diversity but apparently minimized effects of pathogenic microorganisms present in the waste such as Asp. flavus. This may explain the highest survival rate of workers in this treatment.


Asunto(s)
Hormigas/fisiología , Dieta , Heces/microbiología , Animales , Aspergillus flavus/fisiología , Eucalyptus/química , Euphorbiaceae/química , Heces/química , Ligustrum/química , Longevidad , Tasa de Supervivencia
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