Indigenous Arbuscular Mycorrhizal Fungal Assemblages Protect Grassland Host Plants from Pathogens

Plant roots can establish associations with neutral, beneficial and pathogenic groups of soil organisms. Although it has been recognized from the study of individual isolates that these associations are individually important for plant growth, little is known about interactions of whole assemblages of beneficial and pathogenic microorganisms associating with plants. We investigated the influence of an interaction between local arbuscular mycorrhizal (AM) fungal and pathogenic/saprobic microbial assemblages on the growth of two different plant species from semi-arid grasslands in NE Germany (Mallnow near Berlin). In a greenhouse experiment each plant species was grown for six months in either sterile soil or in sterile soil with one of three different treatments: 1) an AM fungal spore fraction isolated from field soil from Mallnow; 2) a soil pathogen/saprobe fraction consisting of a microbial community prepared with field soil from Mallnow and; 3) the combined AM fungal and pathogen/saprobe fractions. While both plant species grew significantly larger in the presence of AM fungi, they responded negatively to the pathogen/saprobe treatment. For both plant species, we found evidence of pathogen protection effects provided by the AM fungal assemblages. These results indicate that interactions between assemblages of beneficial and pathogenic microorganisms can influence the growth of host plants, but that the magnitude of these effects is plant species-specific.

The politicization of indigenous identities in Peru

Until now, scholars have argued that, unlike other Latin American countries with sizable indigenous populations, indigenous politics are largely unimportant in Peru because indigenous-based parties or national-level movements are absent. Rather than focusing solely on the emergence of indigenous parties or movements, which ignores the larger consequence of individuals' indigenous identifications for electoral politics, we argue that it is more important to examine the emergence of indigenous political divisions and their effects on indigenous representation. Using data from the World Values Survey across the presidential elections of 1995, 2001, and 2006, we show that, as indigenous identity has become more carefully defined, indigenous voting divisions have emerged in Peru, and concomitantly, parties have begun to recognize and respond to these divisions.

Copyright & Risk: Scoping the Wellcome Digital Library Project (peer reviewed)

Copyright & Risk: Scoping the Wellcome Digital Library is a comprehensive case study which assesses the merits of the risk-managed approach to copyright clearance adopted by the Wellcome Library in the course of their pilot digitisation project Codebreakers: Makers of Modern Genetics (http://wellcomelibrary.org/collections/digital-collections/makers-of-modern-genetics/#).