79 research outputs found
Microsatellite markers for the yam bean <em>Pachyrhizus</em> (Fabaceae)
Premise of the study: Microsatellite loci were developed for the understudied root crop yam bean (Pachyrhizus spp.) to investigate intraspecific diversity and interspecific relationships within the genus Pachyrhizus.
Methods and Results: Seventeen nuclear simple sequence repeat (SSR) markers with perfect di- and trinucleotide repeats were developed from 454 pyrosequencing of SSR-enriched genomic libraries. Loci were characterized in P. ahipa and wild and cultivated populations of four closely related species. All loci successfully cross-amplified and showed high levels of polymorphism, with number of alleles ranging from three to 12 and expected heterozygosity ranging from 0.095 to 0.831 across the genus.
Conclusions: By enabling rapid assessment of genetic diversity in three native neotropical crops, P. ahipa, P. erosus, and P. tuberosus, and two wild relatives, P. ferrugineus and P. panamensis, these markers will allow exploration of the genetic diversity and evolutionary history of the genus Pachyrhizus
Ethnobiology : the missing link in ecology and evolution
Evolutionary biologists and ecologists increasingly appreciate the value of local knowledge of human communities for research into the past, present, and future of biodiversity. However, there are often significant problems accessing and interpreting this knowledge. Here, we argue that closer interaction with ethnobiologists, who study the relation between humans and the natural world, will enable local knowledge to be better applied in ecological and evolutionary biological research. This will provide more comprehensive answers to the scientific questions being asked, and will result in improved engagement with both academic and non-academic communities
Holistic sustainability assessment of biomethane systems
European states, including Ireland must ensure that an increasing portion of energy from renewable sources. This is a particular issue for transport, which in comparison to electricity and heat has very low levels of renewable penetration. Electric vehicles (EVs), liquid and gaseous biofuels are the most likely sources for future energy in transport. However, renewable does not automatically mean sustainable. For example the sustainability of biofuels sourced from food crops has been queried in the context of land use change emissions. This thesis has an ambition of assessing sustainable options for advanced biomethane production in Ireland, a country with a temperate oceanic climate, using various methodologies (life cycle assessment, energy system modelling and cost analysis). Biomethane is a versatile gaseous biofuel that is considered advanced when produced from second and third generation feedstocks such as wastes, residues, grasses, and seaweed, but a simplified and unified framework for biofuels LCA is required to compare different options. Under a low-level land use change emissions scenario, biomethane from grass could play a major role in the Irish energy system for transport in 2050, requiring only 5-11% of Irelandâs agricultural land. With high land use emissions, however, the model would suggest using hydrogen, residues-based biodiesel, and EVs. Biomethane from seaweed could be deemed unsustainable if the system is not optimised. However in an optimal configuration it could achieve 70% greenhouse gases (GHG) savings as compared to gasoline. Such reductions in GHG emissions can be achieved in an optimal system: integrating seaweed cultivation with fish farming; using innovative growing techniques; ensuring optimal seaweed composition; reusing digestate; and using renewable electricity to power plant operations. Biomethane from landfill gas was shown to require a subsidy to allow financial sustainability. Thus in conclusion, biomethane can be a sustainable transport biofuel, but requires system optimisation and state subsidies
Beyond carbon and energy: the challenge in setting guidelines for life cycle assessment of biofuel systems
Life cycle assessment (LCA) is one of the most suitable tool for a uniform assessment methodology of biofuelsâ sustainability. However, there are no binding guidelines for LCA of biofuel systems. Published LCAs use a range of methodologies, different system boundaries, impact categories and functional units, various allocation approaches, and assumptions regarding by- and co-products, as well as different reference systems to which the biofuel system is compared. The European Renewable Energy Directive and the US Renewable Fuel Standard focus on greenhouse gas (GHG) emissions. However, previous LCAs of biofuel systems have shown that a reduction of GHG emissions does not lead automatically to a decrease in other environmental impacts, and might in fact be associated with an increase in impacts such as acidification, eutrophication, and land use change. In order to enable effective comparison of biofuel systems, the authors propose a framework for biofuel LCA. System boundaries should be expanded to include the life cycle of by- and co-products. Results should be reported using more than one functional unit. Burden shifting can be avoided by considering an array of impact categories including global warming potential and energy balance, along with eutrophication and acidification potential, and a land use indicator
Life cycle assessment of seaweed biomethane, generated from seaweed sourced from integrated multi-trophic aquaculture in temperate oceanic climates
Biomethane produced from seaweed is a third generation renewable gaseous fuel. The advantage of seaweed for biofuel is that it does not compete directly or indirectly for land with food, feed or fibre production. Furthermore, the integration of seaweed and salmon farming can increase the yield of seaweed per hectare, while reducing the eutrophication from fish farming. So far, full comprehensive life cycle assessment (LCA) studies of seaweed biofuel are scarce in the literature; current studies focus mainly on microalgal biofuels. The focus of this study is an assessment of the sustainability of seaweed biomethane, with seaweed sourced from an integrated seaweed and salmon farm in a north Atlantic island, namely Ireland. With this goal in mind, an attributional LCA principle was applied to analyse a seaweed biofuel system. The environmental impact categories assessed are: climate change, acidification, and marine, terrestrial and freshwater eutrophication. The seaweed Laminaria digitata is digested to produce biogas upgraded to natural gas standard, before being used as a transport biofuel. The baseline scenario shows high emissions in all impact categories. An optimal seaweed biomethane system can achieve 70% savings in GHG emissions as compared to gasoline with high yields per hectare, optimum seaweed composition and proper digestate management. Seaweed harvested in August proved to have higher methane yield. August seaweed biomethane delivers 22% lower impacts than biomethane from seaweed harvested in October. Seaweed characteristics are more significant for improvement of biomethane sustainability than an increase in seaweed yield per unit area
Finding the niche: A review of market assessment methodologies for rural electrification with small scale wind power
The mass roll out of solar PV across the Global South has enabled electricity access for millions of people. In the right context, Small Wind Turbines (SWTs) can be complementary, offering the potential to generate at times of low solar resource (night, monsoon season, winter, etc.) and increasing the proportion of the total energy system that can be manufactured locally. However, many contextual factors critically affect the viability of the technology, such as the extreme variability in the wind resource itself and the local availability of technical support. Therefore, performing a detailed market analysis in each new context is much more important. The Wind Empowerment Market Assessment Methodology (WEMAM) is a multi-scalar, transdisciplinary methodology for identifying the niche contexts where small wind can make a valuable contribution to rural electrification. This paper aims to inform the development of WEMAM with a critical review of existing market assessment methodologies. By breaking down WEMAM into its component parts, reflecting upon its practical applications to date and drawing upon insights from the literature, opportunities where it could continue to evolve are highlighted. Key opportunities include shifting the focus towards development outcomes; creating community archetypes; localised studies in high potential regions; scenario modelling and MCDA ranking of proposed interventions; participatory market mapping; and applying socio-technical transitions theory to understand how the small wind niche can break through into the mainstream
Farmer seed networks make a limited contribution to agriculture? Four common misconceptions
The importance of seed provisioning in food security and nutrition, agricultural development and rural livelihoods, and agrobiodiversity and germplasm conservation is well accepted by policy makers, practitioners and researchers. The role of farmer seed networks is less well understood and yet is central to debates on current issues ranging from seed sovereignty and rights for farmers to GMOs and the conservation of crop germplasm. In this paper we identify four common misconceptions regarding the nature and importance of farmer seed networks today. (1) Farmer seed networks are inefficient for seed dissemination. (2) Farmer seed networks are closed, conservative systems. (3) Farmer seed networks provide ready, egalitarian access to seed. (4) Farmer seed networks are destined to weaken and disappear. We challenge these misconceptions by drawing upon recent research findings and the authorsâ collective field experience in studying farmer seed systems in Africa, Europe, Latin America and Oceania. Priorities for future research are suggested that would advance our understanding of seed networks and better inform agricultural and food policy
Development of SSR markers and genetic diversity analysis in enset (Ensete ventricosum (Welw.) Cheesman), an orphan food security crop from Southern Ethiopia
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