Leonor Costa Maia

New Brazilian Floristic List Highlights Conservation Challenges

A comprehensive new inventory of Brazilian plants and fungi was published just in time to meet a 2010 Convention on Biological Diversity target and offers important insights into this biodiversitys global significance. Brazil is the home to the worlds richest flora (40,989 species; 18,932 endemic) and includes two of the hottest hotspots: Mata Atlântica (19,355 species) and Cerrado (12,669 species). Although the total number of known species is one-third lower than previous estimates, the absolute number of endemic vascular plant species is higher than was previously estimated, and the proportion of endemism (56%) is the highest in the Neotropics. This compilation serves not merely to quantify the scale of the challenge faced in conserving Brazils unique flora but also serves as a key resource to direct action and monitor progress. Similar efforts by other megadiverse countries are urgently required if the 2020 targets of the Convention on Biological Diversity and the Global Strategy for Plant Conservation are to be attained.

Tolerance of mycorrhized banana (Musa sp. cv. Pacovan) plantlets to saline stress

Abstract Arbuscular mycorrhizal fungi (AMF) are known to increase plant tolerance to abiotic stress, in particular soil salinity. Isolates of Acaulospora scrobiculata Trappe, Glomus clarum Nicolson & Schenck and Glomus etunicatum Becker & Gerdemann were investigated under glasshouse conditions. Inoculated banana plants (Musa sp. cv. Pacovan) showed higher nutrient contents and growth rates than the controls. G. clarum was particularly efficient as growth promoter, and improved the dry weight of root (80%), shoot (83%), and the total leaf area (60%) compared to non-inoculated plants. The salt tolerance of banana as measured by leaf number and plant height increased considerably in presence of Glomus isolates. Inoculation with specific AMF therefore constitutes an alternative method to reduce banana plant stress caused by soil salinization.

Effect of arbuscular mycorrhizal fungi on the acclimatization of micropropagated banana plantlets

Abstract The effect of arbuscular mycorrhizal fungi (AMF) on micropropagated banana plantlets was evaluated during the acclimatization period. Plants were inoculated with Acaulospora scrobiculata, Glomus clarum or Glomus etunicatum. After cultivation in a greenhouse for 3 months, height, leaf area, fresh weight and dry matter of root and shoots, level of AMF colonization, nutrient level, photosynthesis and transpiration rate, water potential and stomatal conductance were measured. The number of AMF spores produced in each treatment was also determined. Plantlets inoculated with AMF had greater height, leaf area and fresh weight of shoots and roots, as well as higher rates of photosynthesis and transpiration than controls. Plants inoculated with Glomus were superior in most of the evaluated parameters.

Phylogenetic analysis of Glomeromycota by partial LSU rDNA sequences

We analyzed the large subunit ribosomal RNA (rRNA) gene [LSU ribosomal DNA (rDNA)] as a phylogenetic marker for arbuscular mycorrhizal (AM) fungal taxonomy. Partial LSU rDNA sequences were obtained from ten AM fungal isolates, comprising seven species, with two new primers designed for Glomeromycota LSU rDNA. The sequences, together with 58 sequences available from the databases, represented 31 AM fungal species. Neighbor joining and parsimony analyses were performed with the aim of evaluating the potential of the LSU rDNA for phylogenetic resolution. The resulting trees indicated that Archaeosporaceae are a basal group in Glomeromycota, Acaulosporaceae and Gigasporaceae belong to the same clade, while Glomeraceae are polyphyletic. The results support data obtained with the small subunit (SSU) rRNA gene, demonstrating that the LSU rRNA gene is a useful molecular marker for clarifying taxonomic and phylogenetic relationships in Glomeromycota.

Crescimento de mudas de maracujazeiro-doce (Passiflora alata Curtis) associadas a fungos micorrízicos arbusculares (Glomeromycota)

Para determinar o efeito de fungos micorrizicos arbusculares sobre o crescimento de mudas de maracujazeiro-doce foi conduzido, em casa de vegetacao, experimento com delineamento inteiramente casualizado usando cinco tratamentos de inoculacao (200 esporos/planta de Acaulospora longula Spain & Schenck, Gigaspora albida Schenck & Smith, Glomus etunicatum Becker & Gerd., Scutellospora heterogama (Nicol. & Gerd.) Walker & Sanders e controle nao inoculado), com sete repeticoes. A cada 20 dias foram avaliados altura e numero de folhas e ao final do experimento (90 dias): diâmetro do caule, biomassa, area foliar, colonizacao micorrizica e densidade de esporos de FMA na rizosfera. A partir de 70 dias foram evidenciadas diferencas no numero de folhas; aos 90 dias as plantas inoculadas com G. albida apresentaram maior altura que as demais, que nao diferiram significativamente entre si. Plantas associadas com esse fungo apresentaram, em relacao ao controle, incrementos de 2.138% e 1.430% nas biomassas fresca e seca da parte aerea, 1.937% na biomassa fresca da raiz e 2.671% na area foliar. Apesar de nao existir especificidade de hospedeiro na associacao micorrizica arbuscular, apenas G. albida promoveu respostas significativas no maracujazeiro-doce, indicando a existencia de maior compatibilidade funcional entre esses simbiontes.

Intraornatosporaceae ( Gigasporales ), a new family with two new genera and two new species

A new family (Intraornatosporaceae), two new genera (Intraornatospora, Paradentiscutata), two new species (P. bahiana, P. maritima), and a new combination (I. intraornata) are presented in the Gigasporales. The genera, both with diagnostic introverted ornamentations on the spore wall, are distinguished by spore wall structure and germ shield characteristics. The new species, detected in NE Brazil, can be differentiated by their projections on the outer spore surface. Partial sequences of the LSU rRNA gene place both species next to I. intraornata in a monophyletic major clade related to Gigasporaceae and Dentiscutataceae.

Mycorrhizal technology and phosphorus in the production of primary and secondary metabolites in cebil (Anadenanthera colubrina (Vell.) Brenan) seedlings.

BACKGROUND The application of arbuscular mycorrhizal fungi (AMF) can increase the growth and concentration of primary and secondary metabolites in several plant species. Cebil (Anadenanthera colubrina), a medicinal plant, benefits from mycorrhizal association, but the influence of the symbiosis on the production of its bioactive compounds is unknown. In this study the effect of mycorrhizal inoculation and phosphorus (P) supply on the production of primary and secondary metabolites in cebil seedlings was determined. RESULTS The production of proteins and carbohydrates in terms of both concentration and content was enhanced by inoculation with AMF, but this benefit was mitigated at higher levels of P (30 and 50 mg dm(-3) soil). The concentration of phenols, flavonoids and total tannins was favoured by mycorrhizal inoculation even at the highest levels of P (30 and 50 mg dm(-3) soil). CONCLUSION The production of primary and secondary metabolites in leaves of A. colubrina can be maximised by mycorrhization, with the benefit depending on supplementation of soil phosphate.

Produção de mudas de maracujazeiro-doce micorrizadas em solo desinfestado e adubado com fósforo

The objective of this work was to identify the required P dose and efficient arbuscular mycorrhizal fungi (AMF) to promote growth of seedlings of sweet passion fruit. An experiment was carried out at the greenhouse, in a randomized design with a factorial 2x4x4: two soil conditions (disinfected or not), four treatments of inoculation (inoculated or not with Gigaspora albida, Scutellospora heterogama and native AMF from the rhizosphere of sweet passion fruit plants), four doses of available P (Mehlich-1) (8 - natural soil -, 12, 16 and 20 mg dm -3 ), with four replicates. Native AMF promoted growth of seedlings after 30 days of inoculation, while other fungi stimulated plant development after 45 days. Quadratic models indicated maximum values of plant height in soil, with P values estimated between 15.40 and 16.07 mg dm -3 in disinfected soil and 14.85 and 15.60 mg dm -3 in non disinfected soil, obtained in treatments with S. heterogama and G. albida, respectively. Higher spores density and mycorrhizal colonization were observed in treatments with these fungi, comparing with the native AMF. Growth of sweet passion fruit seedlings can be improved by mycorrhization with selected AMF, with reduction of time spent on seedling production.

Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil

The Sao Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO 2 ). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO 2 . Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g -1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm -3 soil in the conventional system to 110 cm -3 soil in the organic system. Microbial carbon, CO 2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards

Arbuscular mycorrhiza in species of Commelinidae (Liliopsida) in the state of Pernambuco (Brazil)

Micorrizas sao associacoes simbioticas mutualisticas formadas entre fungos e raizes de plantas, sendo o principal beneficio para a planta o aumento do aporte de nutrientes. Agronomicamente, a micorriza arbuscular (MA) e o tipo mais importante de micorrizas e apresenta-se distribuido na maioria dos ecossistemas. O objetivo deste trabalho foi estudar a condicao micorrizica de especies de Commelinidae que ocorrem no Estado de Pernambuco. Raizes dessas plantas, coletadas em 10 municipios, foram lavadas, clareadas em KOH, coradas com azul de Tripano em lactoglicerol e observadas em microscopio para determinacao da presenca e identificacao do tipo de micorriza formado. O percentual de colonizacao das raizes foi avaliado pelo metodo de intersecao em placa quadriculada. Quarenta especimens, representando 30 especies, foram observados. Destes especimens, 70% estavam colonizados por fungos micorrizicos arbusculares (FMA). Em uma das familias (Typhaceae) nao foi encontrada a associacao; em duas (Eriocaulaceae e Juncaceae) todos os especimens apresentaram-se micorrizados e tres (Commelinaceae, Cyperaceae e Poaceae) mostraram especimens com ou sem FMA. Em algumas raizes foram observados outros fungos, alem dos micorrizicos. Os resultados indicam que FMA estao amplamente distribuidos entre as especies de Commelinidae em Pernambuco, sendo provavelmente importantes para o estabelecimento das mesmas nas areas de coleta.