scholarly journals Isolation and molecular characterization of symbiotic fungus from Acromyrmex ambiguus and Acromyrmex heyeri ants of Rio Grande do Sul State, Brazil

2015 ◽  
Vol 45 (7) ◽  
pp. 1256-1261 ◽  
Author(s):  
Daniela Isabel Brayer Pereira ◽  
Sônia de Avila Botton ◽  
Maria Isabel de Azevedo ◽  
Danieli Urach Monteiro ◽  
Carla Weiblen ◽  
...  

Leaf-cutting ants of the genera Atta and Acromyrmex determine serious agricultural problems and live on symbiosis with Leucoagaricus gongylophorus. The aim of this study is to identify morphological and molecularly, as well as to verify the genotypic variability of the symbiotic fungus cultivated by A. heyeri and A. ambiguus from three different regions of the state of Rio Grande do Sul, Brazil. Fungus gardens were collected and fragments of mycelia were grown in selective medium. Total DNA was extracted and amplification of the ITS region was performed by PCR using universal primers. After DNA sequencing, the chromatograms were assembled and phylogenetic analyzes were performed by the Neighbor-Joining method. A total of six isolates of L. gongylophorus were obtained and their identities were confirmed by molecular analyses. Phylogenetic analysis of the ITS region showed a tree with two distinct groups regarding the fungus isolates from A. heiyeri and A. ambiguous. In this study, it was verified that A. heyeri and A. ambiguous, cultivate the same fungus. Additionally, the molecular marker used in this study showed variations in L. gongylophorus, evidencing two distinct branches in the phylogenetic tree, according to the ant species that cultivate L. gongylophorus. However, other studies involving the inclusion of a great number of isolates of L. gongylophorus, as well as the use of other molecular markers to validate the possible variations in the phylogenetic relationship of this symbiotic fungus are required.

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Larissa Fonseca

Sinopse: Em meio ao colorido de goiabas, batatas e flores mais que cheiros e sabores, descobrir pessoas. Agricultoras e agricultores que com suas histórias e lutas, estão representados nas varandas e nas mesas da cidade. Trazer a imagem não de uma feira, mas de cada pessoa que diariamente se dedica ao cultivo e à produção de alimentos. Encontrar o rosto e as escolhas de outros modos de fazer agricultura, de outros modos de se alimentar. De assentados e suas lutas pela preservação de sementes crioulas, de jovens universitários e sua determinação em permanecer no campo e de fumicultores aposentados dispostos a limpar suas terras dos venenos de mais 30 anos de cultivos agressivos, é feita a Feira Sabores da Terra. Feira da agricultura familiar do município de Canguçu, Rio Grande do Sul, que acontece todas as segundas-feiras à tarde e reúne cerca de 18 produtores. Em um pavilhão de madeira no centro da cidade são expostos doces coloniais, panificados, frangos congelados, farinhas, feijões, legumes, verduras, frutas e flores, em variedade conforme a estação do ano. Produtos que são vendidos entre boas conversas, rodas de chimarrão e é claro, uma melancia bem gelada ou uma deliciosa rapadura. Para a permanência e continuação da feira, que se realiza há pouco mais de um ano, os feirantes têm enfrentado e superado dificuldades. A distância de suas propriedades até a cidade, muitas das vezes são mais do que duas horas de viagem. A demanda, pelos consumidores, por produtos conforme padrões estéticos dos alimentos produzidos com veneno. O cansaço de mãos que, com mais de 40 anos de trabalho, ainda enfrentam a roça durante toda a semana e o frio, a chuva e o calor de uma feira praticamente ao ar livre. O conciliar o trabalho agrícola e a feira com os estudos, cujo acesso limitado pela distância das universidades, das oportunidades de estágios e pela dificuldade de ascender ao ensino público superior. Apesar de tão próximos, rostos e mãos muitas vezes invisíveis em escolhas alimentares. Gente que oportuniza uma alternativa à alimentação. Alimentação proveniente da relação de mulheres e homens com a terra, de suas sabedorias e ações. Feira Sabores da Terra, um ponto de aproximação entre o campo e a cidade, entre o cultivo e o alimento, entre o cuidado e o sabor. De agricultoras e agricultores e seus feijões, morangos e biscoitos. Este ensaio fotográfico é parte da agenda de pesquisa “Saberes e Sabores da Colônia”, desenvolvida no âmbito do Grupo de Estudos e Pesquisas em Alimentação e Cultura (GEPAC) e vinculada ao Bacharelado e ao Programa de Pós-Graduação em Antropologia da Universidade Federal de Pelotas. Synopsis: In the middle of colored places with guava , potatoes and flowers more than smells of flavors, we discover people. Farmers, with your stories and struggles, are represented on the balconies and tables of the city. Representing the image of each person that daily is dedicated to the cultivation and food production, not just the image of a fair is much more than that. Find the face and choices of other ways of doing agriculture and others ways of feeding. From the land reform settlements and their struggles for the preservation of native seeds, of university students and their determination to remain in the field and retires tobacco growers willing to clear their land of the poisons of another 30 years of aggressive crops, is made the Flavors of the Earth Fair. Family Agriculture Fair, in the Canguçu City in Rio Grande do Sul, Brazil, of what happens on every Monday afternoon and brings together about 18 small farmers. In a wooden pavilion in Downtown city are exposed colonial sweets, bakery products, quick-frozen, flours, beans, vegetables, fruits and flowers in variety according to season. Products that are sold as God´s taste is of course chimarrão, and watermelon ice-cold or a delicious rapadura. For the permanence and continuation of the green fair, been held little more than a year ago, the small farmers have had and overcome difficulties. The distance of their properties of the Downtown , often last more than two hours of the trip. The consumer demand by products according to aesthetic standards of foods produced with venom. The fatigue of hands, still for more than 40 years of work, are still facing small farm during the days in a cool, rain and heat weather and the a fair still open. To reconcile agricultural work and the fair with studies, to which access is restricted by distances from universities, internship opportunities, and the difficulty of access to higher public education. Although close, often invisible faces and hands in food choices. People who offer alternative food. Food derived from the relationship of men and women to the land, of his wisdom and actions. Flavors of The Hearth Fair, a point of approximation between the countryside and the city, between the crop and the food, between care and taste. Of farmers and agriculturists and their beans, strawberries and biscuits. This photo essay is part of research agenda “Knowledge and tastes of the agricultural colony”, developed in the framework of the Group of the Studies and Researches in Food an Culture (GEPAC) and linked to the Bachelor’s and the Postgraduate Program In Anthropology of Federal University of Pelotas. Palavras-chave: Agricultura Familiar – Campesinato – Feira – Alimentação - Consumo Key-words: : Family Agriculture - Peasantry – Fair – Food - Consumption Ficha técnica: Direção: Larissa Fonseca Roteiro: Larissa Fonseca Fotografia: Larissa Fonseca Coordenação de Pesquisa: Renata Menasche Edição de Imagem: Larissa Fonseca e Hamilton Bittencourt Assessoria em Imagem: Claudia Turra Magni Credits: Author: Larissa Fonseca Photographs: Larissa Fonseca Direction: Larissa Fonseca Research Coordination: Renata Menasche Image Editing: Larissa Fonseca e Hamilton Bittencourt Image Consulting: Claudia Turra Magni.


Phytotaxa ◽  
2021 ◽  
Vol 494 (1) ◽  
pp. 42-58
Author(s):  
CELESTE HEISECKE ◽  
JAIME ANDRÉS DUQUE BARBOSA ◽  
MARIA ALICE NEVES ◽  
ANIBAL ALVES DE CARVALHO JR

Leucoagaricus nzumbae sp. nov. (Agaricaceae) is described based on morphological and molecular data from Teresópolis, Rio de Janeiro, Brazil. This species is characterized by the delicate small basidiomes that turn completely lilac when dried, brownish color of the pileus surface, and trichodermal elements with intracellular and parietal brown pigments of the pileus covering. A lectotype and an epitype are designated for Leucoagaricus gongylophorus, a symbiotic fungus of leaf-cutting ants. Full description, nomenclatural notes, and illustrations of fresh basidiomes in situ and of the main macro-and micromorphological features of both species are provided.


2001 ◽  
Vol 61 (4) ◽  
pp. 667-678 ◽  
Author(s):  
E. DIEHI ◽  
A. M. de ARAÚJO ◽  
S. CAVALLI-MOLINA

The breeding structure of both colony and population of social insects can be examined by genetic analysis. Colonies of the leaf-cutting ants Acromyrmex heyeri and A. striatus (Myrmicinae, Attini) were thus analyzed for isoenzyme systems MDH, a-GPDH, and AMY to describe genotype variability and social structure. A total of five loci were investigated (three for amylase and one for each other system). Ninety-seven colonies of A. heyeri and 103 of A. striatus were sampled in different localities in Southern Brazil (State of Rio Grande do Sul). The genotypes found show the occurrence of monogyny and polygyny associated or not with polyandry, which indicates that the social organization is colony-specific. The polygyny and polyandry observed are likely to be responsible for the great genotypic diversity of the colonies. The average inbreeding coefficient per colony was higher in A. striatus than in A. heyeri, which may reflect the different patterns of production of sexual individuals and nuptial flight of those two species.


Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 155-155 ◽  
Author(s):  
Y. Ahmed ◽  
A. M. D'Onghia ◽  
A. Ippolito ◽  
T. Yaseen

During spring-summer 2009, a survey was conducted to determine the species of Phytophthora present in citrus nurseries in Egypt. A total of 300 samples of soil and fibrous roots were collected from the rhizosphere of symptomatic Volkameriana lemon (Citrus volkameriana Tan. & Pasq.) plants growing in Delta (Benha-Qalyubia) and a desert (Cairo/Alexandria desert road) citrus nurseries. Plants showed various symptoms. Canopies of affected plants showed few and yellowish leaves, a general stunted growth, no new vegetation, and sometimes sudden desiccation; the root system showed few dark brown feeder roots, no new yellow-white apexes, and a fibrous appearance of the rootlets due to disintegration of the cortical bark but not of the xylem. Collected rootlets and soil were plated in Petri dishes containing a selective medium for the oomycete Phytophthora (2) and incubated for 3 to 6 days at 19 ± 1°C as described by Ippolito et al. (1). Pure cultures were obtained by single-hypha transfers and the isolates were identified as Phytophthora palmivora (Butler) Butler on the basis of morphological and cultural characteristics (3). Isolates formed stoloniferous colonies on potato dextrose agar (PDA) and grew between 10 and 30°C, with the optimum at 25°C. On V8 juice agar, they showed a highly fluffy pattern and produced terminal and intercalary globose chlamydospores. Sporangia were papillate, elliptical (45 to 51 × 29 to 35 μm; length/breadth ratio of 1.3:1.8), and were caducous with short pedicel. All isolates were A2 mating type, forming spherical oogonia and amphigynous antheridia in dual cultures with reference P. palmivora isolate of A1 mating type. Identification of the isolates was further confirmed by amplification and sequencing of the internal transcribed spacer (ITS) region using the universal primers ITS4 and ITS6. BLASTn analysis of ITS sequences (GenBank Accession No. HE583183) showed 99% homology with P. palmivora isolates available in GenBank. Pathogenicity tests for P. palmivora were conducted by inoculating three groups of ten 6-month-old Volkameriana lemon plants, transplanted into 1.4 liter pots with growing medium artificially inoculated at the rate of 1% (v/v) of P. palmivora inoculum produced according to Yaseen (4). Ten uninoculated plants served as a control. Two months after the inoculation, plants were analyzed for canopy symptoms and the presence of pathogen in feeder roots. More than 50% of inoculated plants showed foliage symptoms and extensive decay of feeder roots. Colonies of Phytophthora were recovered from necrotic rootlets and identified as P. palmivora, fulfilling Koch's postulates. To the best of our knowledge, this is the first report of P. palmivora as a pathogen to citrus plants in the Egyptian nurseries. P. palmivora should be considered a potential threat to the Egyptian citrus industry since it may negatively influence the nurseries and orchards production in the future. References: (1) A. Ippolito, V. De Cicco, and M. Salerno. Rivista di Patologia Vegetale 2:57, 1992. (2) H. Masago, M. Yoshikawa, M. Fukada, and N. Nakanishi. Phytopathology 67:425, 1977. (3) D. J. Stamps. Revised tabular key to the species of Phytophthora. CAB International Mycological Institute, Kew, Surrey, 1990. (4) T. Yaseen. Molecular diagnosis and biological control of Phytophthora-citrus root rot. PhD thesis. University of Bari, Italy, 2004.


Plant Disease ◽  
2009 ◽  
Vol 93 (8) ◽  
pp. 843-843 ◽  
Author(s):  
P. Martini ◽  
A. Pane ◽  
F. Raudino ◽  
A. Chimento ◽  
S. Scibetta ◽  
...  

Oregano (Origanum vulgare L.; Lamiaceae) is cultivated for culinary and medicinal purposes and as an ornamental. In October of 2007, 1- to 2-year-old potted plants of oregano showed symptoms of decline associated with root and basal stem rot in a nursery in Liguria (northern Italy) that produces 1 million to 1.5 million potted aromatic plants per year. Aboveground symptoms included leaf russeting and chlorosis, wilt, defoliation and dieback of twigs, browning of the basal stem, and subsequent collapse of the entire plant. Approximately 80% of the plants died within 30 days after the appearance of the first symptoms on the canopy. Approximately 20% of a stock of 30,000 oregano plants was affected. Stocks of other aromatic species, such as mint, lavender, rosemary, and sage, appeared healthy. A Phytophthora species was consistently isolated from symptomatic stems and roots of oregano plants on BNPRAH selective medium (2). Ten pure cultures were obtained by single-hypha transfers, and the species was identified as Phytophthora tentaculata Kröber & Marwitz by morphological criteria and sequencing of the internal transcribed spacer (ITS) region of rDNA using the ITS 4 and ITS 6 universal primers for DNA amplification. Isolates from oregano formed stoloniferous colonies with arachnoid mycelium on potato dextrose agar and had a growth rate of 2 to 3 mm per day at 24°C with optimum, minimum, and maximum temperatures of 24, 8, and 34°C, respectively. Sporangia formed in soil extract solution and were papillate and spherical or ovoid to obpyriform with a length/breadth ratio of 1.3:1. Few sporangia were caducous and all had a short pedicel (<5 μm). Hyphal swellings and chlamydospores were produced in sterile distilled water and corn meal agar, respectively. All isolates were homothallic and produced globose terminal oogonia (mean diameter of 34 μm) with one or occasionally two paragynous, monoclinous, or diclinous antheridia. Amphigynous antheridia were also observed. The sequence of the ITS region of the rDNA (GenBank No. FJ872545) of an isolate from oregano (IMI 395782) showed 99% similarity with sequences of two reference isolates of P. tentaculata (Accession Nos. AF266775 and AY881001). To test for pathogenicity, the exposed root crowns of 10 6-month-old potted plants of oregano were drench inoculated with 10 ml of a suspension of 2 × 104 zoospores/ml of isolate IMI 395782. Sterile water was pipetted onto the roots of 10 control plants. All plants were maintained in 100% humidity at 22 to 24°C in a greenhouse under natural light and watered once a week. Within 3 weeks after inoculation, all inoculated plants developed symptoms identical to those observed in the nursery and died within 30 to 40 days after the appearance of the first symptoms. Control plants remained healthy. P. tentaculata was reisolated solely from symptomatic plants. P. tentaculata has been reported previously on several herbaceous ornamental plants (1,3). However, to our knowledge, this is the first report of this species on O. vulgare. Root and basal stem rot caused by P. tentaculata is the most serious soilborne disease of oregano reported in Italy so far. References: (1) G. Cristinzio et al. Inf. Fitopatol. 2:28, 2006. (2) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (3) H. Kröber and R. Marwitz. Z. Pflanzenkr. Pflanzenschutz 100:250, 1993.


2003 ◽  
Vol 28 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Andréia M. R. Oliveira ◽  
Valmir Duarte ◽  
José R. P. Silveira ◽  
Marcelo G. Moraes

Erwinia carotovora subsp. atroseptica (Eca), E. carotovora subsp. carotovora (Ecc) and E. chrysanthemi (Ech) may cause potato (Solanum tuberosum) blackleg. To determine the occurrence of these pathogens in the conditions found in the State of Rio Grande do Sul (RS), potato plants showing blackleg symptoms were harvested from 22 fields in nine counties in Serra do Nordeste, Planalto, Depressão Central, and Grandes Lagoas, from September to December of 1999 (Spring-Summer season). Green pepper (Capsicum annuum) fruits were used as a host to enrich for pectolytic erwinia from potato stems with blackleg symptoms. Bacteria were subsequently isolated on non-selective medium. Isolates that were Gram-negative, facultatively anaerobic, and pitted crystal-violet-pectate medium were tested for biochemical traits to identify the species and subspecies. Four hundred strains were identified as either Eca, Ecc or Ech. Although the three erwinias were found in RS potato fields, only three strains of Ech were found in one field. Frequencies of Eca and Ecc were 55 and 42%, respectively. Eight strains could not be assigned based on the biochemical characterization.


2005 ◽  
Vol 60 (7) ◽  
pp. 787-791 ◽  
Author(s):  
Rejane C. de Souza ◽  
João B. Fernandes ◽  
Paulo C. Vieira ◽  
M. Fátima das G. F. da Silva ◽  
Marizete F. P. Godoy ◽  
...  

The stems of Pilocarpus grandiflorus have afforded the new imidazole alkaloid 4,6-dehydro- 1,2,4,5-tetrahydro-2,5-dioxopilocarpine in addition to the 17 known compounds germanicol, β - amiryn, ocotillone, stigmast-4-en-3-one, 3β -hydroxy-stigmast-5-en-7-one, 6β -hydroxy-stigmast-4- en-3-one, β -sitosterol, scopoletin, 3-(1’,1’-dimethylallyl)-scopoletin, elisin, dictamine, 4-methoxy-2- quinolone, platydesmine, syringaresinol, syringaldehyde, syringic acid and vanillic acid. Their structures were elucidated on the basis of chemical and spectroscopic evidence. The phenolic compounds vanillic acid and syringaldehyde and the furoquinoline alkaloid platydesmine exhibited antifungal activity against Leucoagaricus gongylophorus, the symbiotic fungus of leaf-cutting ants (Atta sexdens rubropilosa).


1998 ◽  
Vol 64 (12) ◽  
pp. 4820-4822 ◽  
Author(s):  
Célia Gomes De Siqueira ◽  
Maurício Bacci ◽  
Fernando Carlos Pagnocca ◽  
Odair Correa Bueno ◽  
Maria JoséAparecida Hebling

ABSTRACT Atta sexdens L. ants feed on the fungus they cultivate on cut leaves inside their nests. The fungus, Leucoagaricus gongylophorus, metabolizes plant polysaccharides, such as xylan, starch, pectin, and cellulose, mediating assimilation of these compounds by the ants. This metabolic integration may be an important part of the ant-fungus symbiosis, and it involves primarily xylan and starch, both of which support rapid fungal growth. Cellulose seems to be less important for symbiont nutrition, since it is poorly degraded and assimilated by the fungus. Pectin is rapidly degraded but slowly assimilated by L. gongylophorus, and its degradation may occur so that the fungus can more easily access other polysaccharides in the leaves.


Plant Disease ◽  
2015 ◽  
Vol 99 (1) ◽  
pp. 157-157 ◽  
Author(s):  
T. S. de Oliveira ◽  
L. J. Dallagnol ◽  
J. V. de Araujo Filho ◽  
F. R. de Castro Moretti ◽  
L. E. A. Camargo

Platanus × acerifolia (Aiton) Willd. (London planetree) is a tree commonly used as an ornamental and in the furniture industry. In the summer of 2013, powdery mildew was observed on shoots of P. × acerifolia plants in the cities of Pelotas and Canela (State of Rio Grande do Sul, Brazil). Voucher specimens (n = 2) were deposited in the Phytopathological Museum Manoel Alves Oliveira at Federal University of Pelotas. Dense white powdery masses of conidia and mycelium were observed on leaves (abaxial and adaxial surfaces), petioles, and young stems. Leaves with high disease severities (≥70%) were deformed with curved edges to the adaxial side, and they often died. Mycelia were superficial with lobed appressoria. Conidiophores were straight, sometimes curved at the base, unbranched, cylindrical, 98 to 236 μm long (137.3 ± 41.2 μm) and composed of a cylindrical foot cell 49 to 102 μm long (66.9 ± 19.5 μm) and 4.4 to 6.4 μm wide (5.3 ± 0.8 μm) followed by two to four cells. Conidia were produced singly or in short chains (two to three), without distinct fibrosin bodies, ellipsoid to ovoid and measuring 24 to 37 μm long (29.5 ± 3.2 μm) and 12 to 19 μm wide (15.2 ± 1.4 μm), often with a wrinkled appearance. Primary conidia had truncate bases and rounded apex while both base and apex were truncated in secondary conidia. Germ tubes were produced apically (pseudoidium type). Chasmothecia were not observed. Genomic DNA was used to amplify the internal transcribed spacer (ITS) region using the ITS1 and ITS4 primers. The resulting sequence (602 bp) was deposited (Accession No. KF499270) in GenBank. BLASTn searches revealed similarity of 100 and 99% with Erysiphe platani from P. orientalis L. (Accession No. JQ365943.1) and P. occidentalis L. (Accession No. JX997805.1), respectively. Phylogenetic analysis placed our sequence in a clade (99% bootstrap support) which included only other E. plantani sequences. In short, morphological and molecular approaches allowed us to identify the infecting fungus as E. platani. For Koch's postulates, 10 detached leaves were inoculated (10 to 15 conidia cm2) on their adaxial surface using an eyelash brush. Non-inoculated leaves served as control. All leaves were kept inside trays with petiole immersed in humidified cotton and maintained at 25 ± 1°C. Symptoms identical to those of the original leaves were observed 6 to 8 days after inoculation, whereas the control leaves remained symptomless. Although E. platani has been previously reported on P. × acerifolia in the city of Poços de Calda, state of Minas Gerais, Brazil (1) and on P. occidentalis in Korea (2), to our knowledge, this is the first record of E. platani on P. × acerifolia in Rio Grande do Sul, Brazil. References: (1) E. M. Inokuti et al. New Dis. Rep. 15:38, 2007. (2) Y. J. La and H. D. Shin. Plant Dis. 97:843, 2013.


Author(s):  
Emanuele B. Manke ◽  
Claudia F. A. Teixeira-Gandra ◽  
Rita de C. F. Damé ◽  
André B. Nunes ◽  
Maria C. C. Chagas Neta ◽  
...  

ABSTRACT Although several studies have evaluated the intensity-duration-frequency relationships of extreme rainfall events, these relationships under different seasonal conditions remain relatively unknown. Thus, this study aimed to determine whether the intensity-duration-frequency relationships obtained seasonally from the rainfall records in the winter and summer represent the maximum rainfall events for the city of Pelotas, Rio Grande do Sul state, Brazil. Pluviographic data from 1982 to 2015 were used to create two seasonal series: one for the summer from December 21 to March 20 and the other for the winter from June 21 to September 22. These seasonal relationships were compared with the annual pluviographic data. The intensity, duration, and frequency relationships obtained from the summer rain data adequately represented the maximum rainfall in Pelotas, Rio Grande do Sul state, Brazil. The maximum intensity values of rainfall obtained from the relationship of intensity, duration, and frequency for the winter did not adequately encapsulate the occurrence of rain with greater intensities.


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