Instituto Spegazzini

La Plata, Argentina

Instituto Spegazzini

La Plata, Argentina
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Hospitaleche C.A.,Museo de La Plata | Marquez G.,Catedra de Palinologia | Perez L.M.,Division Paleozoologia Invertebrados | Rosato V.,Instituto Spegazzini | Cione A.L.,Museo de La Plata
Journal of Integrative Environmental Sciences | Year: 2011

Different traces occur on fossil bones and teeth coming from the Early Miocene Gaiman Formation (Patagonia, Argentina). Most traces were attributed to the action of terrestrial and marine predators and scavengers. However, other traces on bones and teeth from this unit and one tooth from the Eocene La Meseta Formation (Antarctica) are attributed to chemical corrosion by lichens in recent times, that is, in a very late diagenetic time. The living lichens and calcium oxalate deposits occurring on the traces and their particular pattern indicates that they were not produced by vegetal roots. The lichens include reproductive structures which allowed a proper determination. A kind of corrosion pattern (Type 1) on bones and teeth from Patagonia is associated to Sarcogyne orbicularis Körber, Verrucaria sp. Schrad, and Buellia aff. punctiformis (Hoff.) Massal. The lichen Aspicilia aff. Aquatica produced rounded holes on an Antarctic tooth (Type 2). On the same tooth, the epilithic lichen Caloplaca sp. Th. Fries did not leave any kind of mark on the enameloid. © Taylor & Francis Group, LLC.

Becerra A.,National University of Cordoba | Bartoloni N.,University of Buenos Aires | Cofre N.,National University of Cordoba | Soteras F.,National University of Cordoba | Cabello M.,Instituto Spegazzini
Boletin de la Sociedad Argentina de Botanica | Year: 2016

Arbuscular mycorrhizal fungi (AMF) colonize approximately 82% of land plants in every ecosystem, even in extreme conditions such as saline soils. In the present work we report the arbuscular mycorrhizal colonization and its vertical root concentration in four Chenopodiaceae plants species (Allenrolfea patagonica, Atriplex argentina, Heterostachys ritteriana and Suaeda divaricata) at five different soil depths in two salines of central Argentina. All the plant species showed mycorrhizal colonization and varied significantly among plant species and sites for all soil depths. Atriplex argentina presented the highest mycorrhizal colonization at almost all soil depths (0-50 cm). In all plant species root concentration decrease as depth increases at both sites. The presence of mycorrhizal roots in the deeper layers of soil in the four Chenopodiaceae plants species, shows that these fungi are tolerant to live in the saline soils of central Argentina.

Soteras F.,National University of Cordoba | Becerra A.,National University of Cordoba | Cofre N.,National University of Cordoba | Bartoloni J.,University of Buenos Aires | Cabello M.,Instituto Spegazzini
Sydowia | Year: 2012

Natural saline soils of Central Argentina have rarely been the focus of arbuscular mycorrhizal fungi (AMF) which are Glomeromycota. We explored the vertical distribution of spores of different AMF species in the rhizosphere of Atriplex lampa in two saline environments (Salinas Grandes and Salinas de Ambargasta) during wet and dry seasons. 18 AMF species were identified. Spore numbers were highest at Salinas Grandes during the wet season. Soil depth showed an influence on spore abundance of some specific species. Our results highlight the effect of soil depth, seasons and soil characteristics on sporulation of AMF species under saline conditions.

Becerra A.G.,National University of Cordoba | Cabello M.N.,Instituto Spegazzini | Bartoloni N.J.,University of Buenos Aires
Mycologia | Year: 2011

The arbuscular mycorrhizal fungal (AMF) communities from the Yungas forests of Argentina were studied. The AMF species present in the rhizosphere of some dominant native plants (one tree: Alnus acuminata; three herbaceous species: Duchesnea indica, Oxalis conorrhiza, Trifolium aff. repens; and one shrub: Sambucus peruviana) from two sites (Quebrada del Portugués and Narváez Range) of the Yungas forests were isolated, identified and quantified during the four seasons of the year. Twenty-two AMF morphotaxa were found. Spore density of some AMF species at each site varied among seasons. The genera that most contributed to the biodiversity index were Acaulospora for Quebrada del Portugués and Glomus for Narváez Range. High diversity values were observed in the Yungas forests, particularly in the spring (rainy season). We concluded AMF differed in species composition and seasonal sporulation dynamics in the Yungas forests. © 2011 by The Mycological Society of America.

Soteras F.,National University of Cordoba | Cofre N.,National University of Cordoba | Bartoloni J.,University of Buenos Aires | Cabello M.,Instituto Spegazzini | Becerra A.,National University of Cordoba
Boletin de la Sociedad Argentina de Botanica | Year: 2013

Atriplex lampa is a valuable fodder shrub available for browsing by livestock even during drought periods in the Chaco Phytogeographical Province. Halophytes may benefit from the association with arbuscular mycorrhizal fungi (AMF) through improved tolerance to drought and salt. Ecological studies of AMF are generally restricted to the main rooting zone. However, AMF vertical distribution and seasonal dynamics in natural saline soils of Argentina have been poorly studied. The aim of this work was to explore AMF root colonization, root concentration and to identify AMF morphoespecies in A. lampa rhizosphere in two saline environments (Salinas de Ambargasta and Salinas Grandes) of central Argentina, in five soil depth levels, during the wet and dry seasons. Despite we did not find arbuscules, AMF were found colonizing A. lampa roots in all depth levels. Salinas Grandes showed the highest root colonization value, and showed the highest root concentration, during wet season. The 20 AMF morphospecies identified in this work belonged to the genera: Acaulospora, Ambispora, Claroideoglomus, Diversispora, Funneliformis, Glomus, Septoglomus and Scutellospora. This is the second record in Argentina of AMF structures in A. lampa roots. Future studies that evaluate mycorrhizal dependency of the plant are necessary to confirm the function of the symbiosis.

Lax P.,National University of Cordoba | Becerra A.G.,National University of Cordoba | Soteras F.,National University of Cordoba | Cabello M.,Instituto Spegazzini | Doucet M.E.,National University of Cordoba
Biology and Fertility of Soils | Year: 2011

Information about the interaction between arbuscular mycorrhizal fungi (AMF) and the false root-knot nematode Nacobbus aberrans (Thorne, 1935) Thorne & Allen, 1944 is scarce. The effect of Glomus intraradices Schenk & Smith on tomato (Lycopersicon esculentum L.) cv. Platense inoculated with nematode juveniles from Lisandro Olmos (Argentina) was studied under greenhouse conditions. Six treatments with five replications were performed. After 80 days, nematode reproduction and percentage of AMF colonization in roots were estimated. Some plant growth parameters were also measured. In general, plants with AMF and AMF plus nematodes grew as well as the control without AMF and without nematodes. Furthermore, G. intraradices was beneficial in reducing nematode-induced damage in roots (lower number of galls) as well as in having a suppressive effect on parasite reproduction. This is the first study on the use of G. intraradices as a possible strategy in the control of N. aberrans in tomato. © 2010 Springer-Verlag.

Velazquez M.S.,Instituto Spegazzini | Biganzoli F.,University of Buenos Aires | Cabello M.N.,Instituto Spegazzini
Sydowia | Year: 2010

There is considerable interest in documenting the biodiversity of plants together with the associated microorganisms. We investigated the species composition and colonisation patterns of arbuscular mycorrhizal fungi (AMF) in five vegetation types in El Palmar National Park, Entre Rios, Argentina. The plant communities consisted of: gallery forest, grassland, marsh, palm forest and scrubland. The roots of 103 plant species of 42 families were examined for AMF colonisation. Ninety-three plant species were found to be colonized. Arum-type mycorrhizal colonisation occurred in 74 species, Paris-type in three species, three species had a mix of both Paris- and Arum-type. It was not possible to determine the colonisation type for 13 plant species. A total of 46 taxa of AMF, including the genera Glomus (15 taxa), Acaulospora (14 taxa), Scutellospora (8 taxa), Gigaspora (5 taxa), Archaeospora (1 taxon), Entrophospora (1 taxon), Pacispora (1 taxon) and Paraglomus (1 taxon), were identified. A higher diversity was observed in the grassland and palm forest, mainly due to a high proportion of Acaulosporaceae and Gigasporaceae. El Palmar National Park contains a well-established, highly diverse, native community of AMF. Consequently, the park may act as a place for in situ conservation of Glomer-omycota.

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