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Summary: Sequencing herbarium specimens can be instrumental in answering ecological, evolutionary, and taxonomic inquiries. We developed a protocol for sequencing herbarium specimens of rust fungi (Pucciniales) and proceeded to sequence specimens ranging from 4 to 211 yr old from five different genera.We then obtained sequences from an economically important biological control agent, Puccinia suaveolens, to highlight the potential of sequencing herbarium specimens in an ecological sense and to evaluate the following hypotheses: (1) The population structure of a plant pathogen changes over time, and (2) introduced pathogens are more diverse in their native range.Our efforts resulted in sequences from 87 herbarium specimens that revealed a high level of diversity with a population structure that exhibited spatial–temporal patterns. The specimens sequenced from Europe showed more diversity than the ones from North America, uncovering an invasion pattern likely related to its European native host in North America. Additionally, to the best of our knowledge, the specimen from France collected in c. 1811 is the oldest herbarium specimen sequenced from kingdom Fungi.In conclusion, sequencing old herbarium specimens is an important tool that can be extrapolated to better understand plant–microbe evolution and to evaluate old type specimens to solidify the taxonomy of plant pathogenic fungi. [ABSTRACT FROM AUTHOR]

Botanical gardens have extensive spatial databases of their plant specimens; however, the fungi occurring in them are generally unstudied. Botanical gardens, with their great plant diversity, undoubtedly harbor a wide range of symbiotic fungi, including those that are plant-pathogenic. One such group of fungi is powdery mildews (Erysiphaceae). The powdery mildews are among the most prevalent and economically important plant pathogens in the world, with an estimated 906 species in 19 genera. They are known to infect more than 10,000 species of flowering plants and although some species occur across a range of hosts, many are associated with specific plants. Powdery mildews have undergone a long and dynamic coevolution with their host plants, resulting in co-speciation. Botanical gardens provide a living laboratory in which to study these fungi, leading to a wealth of undiscovered fungal diversity. Furthermore, monitoring pathogens in botanical gardens has led to important ecological findings related to the plant sciences and plant protection. Between 2018 and 2022, a collaborative citizen science project was established with 10 botanical gardens in the United States and Mexico. A total of more than 300 powdery mildew specimens were collected on 220 different host taxa. We sequenced the entire internal transcribed spacer (ITS) and large subunit (LSU) rDNA loci and phylogenetically and morphologically analyzed these collections revealing 130 species, of which 31 are likely unknown to science. This research highlights the importance of botanical gardens as a reservoir of fungal diversity. Future research will further elucidate the coevolutionary relationship between powdery mildews and their hosts and extend the current study to evaluate other plant pathogens and fungi in botanical gardens. [ABSTRACT FROM AUTHOR]

Mycotoxin contamination is a leading cause of food spoilage and waste on a global scale. Patulin, a mycotoxin produced by Penicillium spp. during postharvest pome fruit decay, causes acute and chronic effects in humans, withstands pasteurization, and is not eliminated by fermentation. While much is known about the impact of patulin on human health, there are significant knowledge gaps concerning the effect of patulin during postharvest fruit–pathogen interactions. Application of patulin on six apple cultivars reproduced some blue mold symptoms that were cultivar-independent and dose-dependent. Identical symptoms were also observed in pear and mandarin orange. Six Penicillium isolates exposed to exogenous patulin exhibited delayed germination after 24 h, yet all produced viable colonies in 7 days. However, four common postharvest phytopathogenic fungi were completely inhibited by patulin during conidial germination and growth, suggesting the toxin is important for Penicillium to dominate the postharvest niche. Using clorgyline, a broad-spectrum efflux pump inhibitor, we demonstrated that efflux plays a role in Penicillium auto-resistance to patulin during conidial germination. The work presented here contributes new knowledge of patulin auto-resistance, its mode of action, and inhibitory role in fungal–fungal interactions. Our findings provide a solid foundation to develop toxin and decay mitigation approaches. [ABSTRACT FROM AUTHOR]

Fungicides are the primary tools to control a wide range of postharvest fungal pathogens. Fungicide resistance is a widespread problem that has reduced the efficacy of fungicides. Resistance to FRAC-1 (Fungicide Resistance Action Committee-1) chemistries is associated with mutations in amino acid position 198 in the β-tubulin gene. In our study, we conducted a meta-analysis of β-tubulin sequences to infer temporal, spatial, plant host, and pathogen genus patterns of fungicide resistance in postharvest fungal pathogens. In total, data were acquired from 2,647 specimens from 12 genera of fungal phytopathogens residing in 53 countries on >200 hosts collected between 1926 and 2020. The specimens containing a position 198 mutation were globally distributed in a variety of pathosystems. Analyses showed that there are associations among the mutation and the year an isolate was collected, the pathogen genus, the pathogen host, and the collection region. Interestingly, fungicide-resistant β-tubulin genotypes have been in a decline since their peak between 2005 and 2009. FRAC-1 fungicide usage data followed a similar pattern in that applications have been in a decline since their peak between 1997 and 2003. The data show that, with the reduction of selection pressure, FRAC-1 fungicide resistance in fungal populations will decline within 5 to 10 years. Based on this line of evidence, we contend that a β-tubulin position 198 mutation has uncharacterized fitness cost(s) on fungi in nature. The compiled dataset can inform end users on the regions and hosts that are most prone to contain resistant pathogens and assist decisions concerning fungicide resistance management strategies. [ABSTRACT FROM AUTHOR]

This paper examines the relationship between global energy security and climate change policy. There are growing concerns about the sustainability of the future supply of hydrocarbons. The energy system is the single largest source of anthropogenic greenhouse gases, therefore it is no surprise that decarbonising the supply of energy services is a key element of climate change policy. The central proposition of this paper is that the world faces a global energy dilemma: can we have secure, reliable and affordable supplies of energy and, at the same time, manage the transition to a low-carbon energy system? The paper is divided into five sections. The first section considers the contemporary challenges to global energy security, focusing on the possibility that in the future oil production might not be able to meet demand. The second section considers how the perils of climate change are forcing us to rethink the very meaning of energy security such that a low-carbon energy revolution is now called for. The third section explains that while the developed world is largely responsible for the anthropogenic carbon emissions currently in the atmosphere, a global shift in energy demand is underway and over the next 20 years it is the developing world that will contribute an ever-increasing share of global emissions. The fourth section introduces the notion of the global energy dilemma nexus to explain how the processes of globalisation are the driving force behind this global shift in energy demand and carbon emissions. The final section explains how the global energy dilemma nexus plays itself out in different ways across the globe. The conclusions suggest that human geography can make a significant contribution to social science research on energy security and climate change. [ABSTRACT FROM AUTHOR]

Argues that there is no alternative to a continuation of self-reliance and autonomous power generation in the development of Sakhalin oil and gas in Russia. Examination of the fuel and energy complex of the Russian Far East; Lack of proper institutional restructuring of natural monopolists; Consequences of populist price controls for coal, fuel and energy.

Theorizing in economic geography has focused on core regions, industrial and non-industrial, old and new. Indeed, contemplation of the idea of globalization has reinforced this quest. This paper disputes this blinkered thinking that peripheralizes resource peripheries, and seeks to re-position and emphasize resource peripheries within economic geography's theoretical agenda, specifically that associated with the new ‘institutional’ approach. A truly ‘global’ economic geography cannot afford to ignore resource peripheries. In particular, we argue that characterizing resource peripheries, and making them distinct from cores, is the intersection of four sets of institutional values or dimensions which we summarize in terms of industrialism (economic dimension), environmentalism (environmental dimension), aboriginalism (cultural dimension) and imperialism (geopolitical dimension). This admittedly preliminary framework underlies our hypothesis that resource peripheries around the world have become deeply contested spaces, much more so than those found in cores. [ABSTRACT FROM AUTHOR]