A genetic study on subtropical Anadenanthera colubrina (Vell.) Brenan var. cebil (Griseb.) Altschul tree from Northwestern Argentina

Anadenanthera colubrina (Vell.) Brenan var. cebil (Griseb.) Altschul is a tree species in South America important for its cultural, economic, and medicinal uses. In addition, it represents a trace in memory of the forests that have decreased over the years and for this reason it is not only interesting to study but also important to preserve the tree species for future generations. In this paper, we have characterized the genetic diversity of four populations. We collected seeds from four different sites: San Bernardo (B), El Cebilar (C), Met\ue1n (M), and El Gallinato (G) in Salta Province, North Argentina. We then compared the intergenic transcribed sequences of ribosomal DNA, a known genetic molecular marker. Our previous results, obtained through the morphological and genetic analysis of only four individuals (one for each zone), have showed that the individuals from B and M sites were more similar to each other as well as the individuals from G and C sites. In this paper, a larger number of individuals (25) were characterized and their phylogenetic relationships were computed. The results confirmed the previously found similarities

Subtropical Dry Forests: The Main Forest Ecoregion of Argentina

The Chaco is a sparsely populated, wooded grassland natural region of the Río de la Plata basin, where four physiognomic regions can be identified: Humid Chaco, Semi-arid Chaco, Arid Chaco, and Chaco Serrano. In this introduction to the section of subtropical dry forests, the most relevant tree genera and species are presented. A severe degradation and deforestation process characterize this region in the current century. The main productive systems are described, together with their effects on environmental, economic, and social aspects: extraction of firewood, production of charcoal, and extensive livestock. The recent advance of the agricultural frontier threatens the native communities living within and from the forest in an ancient equilibrium: changes in land use, technological advances of agriculture, increase of logging in the natural forest are occurring. A new tree-centered production paradigm is needed. “Quebracho” species represent a historical paradigm of overexploitation but a promise of possible sustainable management. Key species for the reconversion of the productive systems in the Chaco (not treated in the following chapters) are presented, taking into account their potential for breeding and relevance for restoration, within the environmental, economic, and social context of the region.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Verga, Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Agencia De Extensión Rural La Rioja; ArgentinaFil: Lopez Lauenstein, Diego. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Lopez Lauenstein, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); Argentin

The seed endosphere of Anadenanthera colubrina is inhabited by a complex microbiota, including Methylobacteriumspp. and Staphylococcus spp. with potential plant-growth promoting activities

Background and aims Plant seeds are emerging micro–habitats, whose importance as reservoir and vector of beneficial microbes just begins to be recognized. Here we aimed to characterize the bacterial microbiota of the Anadenanthera colubrina seed endosphere, with special focus to beneficial traits and to the colonization pattern. Methods Cultivation–dependent (isolation from surface–sterilized seeds) and cultivation–independent (pyrosequencing of 16S rRNA gene from metagenomic seed DNA) analyses, functional tests and microscopical investigations (fluorescence in situ hybridization coupled with confocal laser scanning microscopy (FISH-CLSM) were performed. Results We isolated several Methylobacterium and Staphylococcus spp., exhibiting both plant growth promotion and antimicrobial activities. The two taxonomic groups showed complementary traits, which supports a functional selection. Both genera were detected also by pyrosequencing, together with further taxa. The genera Friedmaniella, Bifidobacterium, Delftia, Anaerococcus and Actinomyces appeared here for the first time as seed endophytes. We detected bacterial cells and micro–colonies in seed cryosections by FISHCLSM. Alphaproteobacteria, Firmicutes and other bacteria colonized intercellular spaces of the parenchyma and associated to transport vessels. Conclusions This work sheds light onto the diversity, functions and colonization pattern of the Anadenanthera colubrina seed endophytes, and strongly suggest a role as beneficial partners for seed-associated microbiot