Linking genebanks and farmers to urban high-value markets - The case of chili peppers in Peru and Bolivia [Poster]

Poster presented at Tropentag Conference. Stuttgart-Hohenheim (Germany), 17-19 Sep 201

Diversity and conservation of traditional African vegetables: Priorities for action

© 2020 The Authors. Diversity and Distributions published by John Wiley & Sons Ltd.Aim: Traditional African vegetables have high potential to contribute to healthy diets and climate resilience in sub-Saharan African food systems. However, their genetic resources are likely at threat because they are underutilized and under the radar of agricultural research. This paper aims to contribute to a conservation agenda for traditional African vegetables by examining the geographical diversity and conservation status of these species. Location: Sub-Saharan Africa. Methods: 126 traditional annual and perennial African vegetables were selected for their food and nutrition potential. Food uses and species’ areas of origin were recorded from literature. Species’ presence records were collected from open-access databases of genebanks and herbaria. These records were used to determine geographical patterns of observed and modelled richness, to distinguish geographical clusters with different compositions of vegetables, to assess species’ ex situ and in situ conservation status and to prioritize countries for conservation actions. Results: Of the 126 species, 79 originated in sub-Saharan Africa. High levels of observed and modelled species richness were found in: (a) West Tropical Africa in Ghana, Togo and Benin; (b) West-Central Tropical Africa in South Cameroon; (c) Northeast and East Tropical Africa in Ethiopia and Tanzania; and (d) Southern Africa in Eswatini. South Sudan, Angola and DR Congo are potential areas of high species richness that require further exploration. In general, ex situ conservation status of the selected species was poor compared to their in situ conservation status. Main conclusions: Areas of high species richness in West Tropical Africa, South Cameroon and Ethiopia coincide with centres of crop domestication and cultural diversity. Hotspots of diversity in Tanzania and Eswatini are especially rich in wild vegetables. Addressing the conservation of vegetable diversity in West Tropical Africa and South Cameroon is of most urgent concern as vegetable genetic resources from these locations are least represented in ex situ collections.publishedVersio

Suitability of key Central American agroforestry species under future climates: an Atlas.

This atlas provides habitat suitability maps for 54 species that are widely used in Central America for shade in coffee or cocoa agroforestry systems. The 54 species represent 24 fruit species, 24 timber species and 6 species used for soil fertility improvement. Suitability maps correspond to the baseline climate (1960-1990) and 2050 climates predicted for Representative Concentration Pathways (RCP) 4.5 and 8.5. Habitat was classified as suitable in future climates if a minimum of 12 out of 17 downscaled Global Circulation Models predicted suitable climates. Details of the methodology of ensemble suitability modelling with the BiodiversityR package are provided in the atlas. The atlas was developed to support climate change oriented initiatives for diversification and conservation of forest genetic resources across Central America. Farmers, scientists and technicians can use the atlas to identify suitable and vulnerable areas for shade species and develop strategies for climate change adaptation. This work has been possible by the financial support of the CGIAR research program on Forests, Trees and Agroforestry (FTA; supported by the CGIAR Fund Donors); the CGIAR research program on Climate Change Agriculture and Food Security (CCAFS; supported by the CGIAR Fund Donors) and HIVOS. The authors of this atlas are scientists of Bioversity International, CATIE and the World Agroforestry Centre

Flux variability of phyto- and zooplankton communities in the Mauritanian coastal upwelling between 2003 and 2008

Continuous multiyear records of sediment-trap-gained microorganism fluxes are scarce. Such studies are important to identify and to understand the main forcings behind seasonal and multiannual evolution of microorganism flux dynamics. Here, we assess the long-term flux variations and population dynamics of diatoms, coccolithophores, calcareous and organic dinoflagellate cysts, foraminifera and pteropods in the eastern boundary upwelling ecosystem of the Canary Current. A multiannual, continuous sediment trap experiment was conducted at the mooring site CBeu (Cap Blanc eutrophic; ∼20∘ N, 18∘ W; trap depth is ca. 1300 m) off Mauritania (northwest Africa), between June 2003 and March 2008. Throughout the study, the reasonably consistent good match of fluxes of microorganisms and bulk mass reflects the seasonal occurrence of the main upwelling season and relaxation and the contribution of microorganisms to mass flux off Mauritania. A clear successional pattern of microorganisms, i.e., primary producers followed by secondary producers, is not observed. High fluxes of diatoms, coccolithophores, organic dinoflagellate cysts, and planktonic foraminifera occur simultaneously. Peaks of calcareous dinoflagellate cysts and pteropods mostly occurred during intervals of upwelling relaxation. A striking feature of the temporal variability of population occurrences is the persistent pattern of seasonal groups contributions. Species of planktonic foraminifera, diatoms, and organic dinoflagellate cysts typical of coastal upwelling, as well as cooler-water planktonic foraminifera and the coccolithophore Gephyrocapsa oceanica, are abundant at times of intense upwelling (late winter through early summer). Planktonic foraminifera and calcareous dinoflagellate cysts are dominant in warm pelagic surface waters, and all pteropod taxa are more abundant in fall and winter when the water column stratifies. Similarly, coccolithophores of the upper and lower photic zones, together with Emiliania huxleyi, and organic dinoflagellate cysts dominate the assemblage during phases of upwelling relaxation and deeper layer mixing. A significant shift in the “regular” seasonal pattern of taxa relative contribution is observed between 2004 and 2006. Benthic diatoms strongly increased after fall 2005 and dominated the diatom assemblage during the main upwelling season. Additional evidence for a change in population dynamics is the short dominance of the coccolithophore Umbilicosphaera annulus, the occurrence of the pteropod Limacina bulimoides and the strong increase in the flux of calcareous dinoflagellate cysts, abundant in warm tropical oligotrophic waters south of the study area after fall 2005. Altogether, this suggests that pulses of southern waters were transported to the sampling site via the northward Mauritania Current. Our multiannual trap experiment provides a unique opportunity to characterize temporal patterns of variability that can be extrapolated to other eastern boundary upwelling ecosystems (EBUEs), which are experiencing or might experience similar future changes in their plankton community

Screening genetic resources of Capsicum peppers in their primary centre of diversity in Bolivia and Peru

For most crops, like Capsicum, their diversity remains under-researched for traits of interest for food, nutrition and other purposes. A small investment in screening this diversity for a wide range of traits is likely to reveal many traditional varieties with distinguished values. One objective of this study was to demonstrate, with Capsicum as model crop, the application of indicators of phenotypic and geographic diversity as effective criteria for selecting promising genebank accessions for multiple uses from crop centers of diversity. A second objective was to evaluate the expression of biochemical and agromorphological properties of the selected Capsicum accessions in different conditions. Four steps were involved: 1) Develop the necessary diversity by expanding genebank collections in Bolivia and Peru; 2) Establish representative subsets of ~100 accessions for biochemical screening of Capsicum fruits; 3) Select promising accessions for different uses after screening; and 4) Examine how these promising accessions express biochemical and agromorphological properties when grown in different environmental conditions. The Peruvian Capsicum collection now contains 712 accessions encompassing all five domesticated species (C. annuum, C. chinense, C. frutescens, C. baccatum, and C. pubescens). The collection in Bolivia now contains 487 accessions, representing all five domesticates plus four wild taxa (C. baccatum var. baccatum, C. caballeroi, C. cardenasii, and C. eximium). Following the biochemical screening, 44 Bolivian and 39 Peruvian accessions were selected as promising, representing wide variation in levels of antioxidant capacity, capsaicinoids, fat, flavonoids, polyphenols, quercetins, tocopherols, and color. In Peru, 23 promising accessions performed well in different environments, while each of the promising Bolivian accessions only performed well in a certain environment. Differences in Capsicum diversity and local contexts led to distinct outcomes in each country. In Peru, mild landraces with high values in health-related attributes were of interest to entrepreneurs. In Bolivia, wild Capsicum have high commercial demand

Distributions, conservation status, and abiotic stress tolerance potential of wild cucurbits (Cucurbita L.)

Societal Impact Statement Crop wild relatives—wild species closely related to cultivated plants—are valuable genetic resources for crop improvement, but gaps in knowledge constrain their conservation and limit their further use. We develop new information on the distributions, potential breeding value, and conservation status of the 16 known wild relatives of cultivated pumpkins, squashes, zucchini, and gourds (Cucurbita L.). The taxa occur from the central USA to Central America, plus two South American species, with the greatest richness in central Mexico and the western borderlands between Mexico and the USA. We determine the majority of species are of medium priority for conservation, both with regard to collecting for ex situ maintenance, and for enhanced habitat protection. Summary Crop wild relatives are valuable genetic resources for crop improvement. Knowledge gaps, including with regard to taxonomy, distributions, and characterization for traits of interest constrain their use in plant breeding. These deficiencies also affect conservation planning, both with regard to in situ habitat protection, and further collection of novel diversity for ex situ maintenance. Here we model the potential ranges of all 16 known wild cucurbit taxa (Cucurbita L.), use ecogeographic information to infer their potential adaptations to abiotic stresses, and assess their ex situ and in situ conservation status. The taxa occur from the central USA to Central America, plus two South American species. Predicted taxon richness was highest in central Mexico and in the western borderlands between Mexico and the USA. We find substantial ecogeographic variation both across taxa and among populations within taxa, with regard to low temperatures, high and low precipitation, and other adaptations of potential interest for crop breeding. We categorize 13 of the taxa medium priority for further conservation as a combination of the ex situ and in situ assessments, two low priority, and one sufficiently conserved. Further action across the distributions of the taxa, with emphasis on taxonomic richness hotspots, is needed to comprehensively conserve wild Cucurbita populations

Development of core collections in soybean on the basis of seed size

Core collections display a large fraction of the diversity contained in large collections in smaller germplasm panels. We used historical data (1973–2015) collected at the World Vegetable Center, Taiwan, for developing soybean (Glycine max L. Merr.) core collections representing the diversity of the whole collection of 7853 accessions held by the Center. The collection was split into two groups on the basis of the 100 seed weight: large seeded (>25 g or equal to 25 g) and small seeded (<25 g). The large-seeded group (vegetable soybean/edamame) comprised 456 accessions, while the small-seeded group contained 7397 accessions. Within these two groups, we developed core collections based on seven quantitative and 14 qualitative traits collected during the autumn season, resulting in a core collection of 112 large-seeded vegetable soybean accessions and 1480 accessions for the small-seeded types

Selective preservation of organic matter in marine environments; processes and impact on the sedimentary record

© The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Biogeosciences 7 (2010): 483-511, doi: 10.5194/bg-7-483-2010The present paper is the result of a workshop sponsored by the DFG Research Center/Cluster of Excellence MARUM "The Ocean in the Earth System", the International Graduate College EUROPROX, and the Alfred Wegener Institute for Polar and Marine Research. The workshop brought together specialists on organic matter degradation and on proxy-based environmental reconstruction. The paper deals with the main theme of the workshop, understanding the impact of selective degradation/preservation of organic matter (OM) in marine sediments on the interpretation of the fossil record. Special attention is paid to (A) the influence of the molecular composition of OM in relation to the biological and physical depositional environment, including new methods for determining complex organic biomolecules, (B) the impact of selective OM preservation on the interpretation of proxies for marine palaeoceanographic and palaeoclimatic reconstruction, and (C) past marine productivity and selective preservation in sediments. It appears that most of the factors influencing OM preservation have been identified, but many of the mechanisms by which they operate are partly, or even fragmentarily, understood. Some factors have not even been taken carefully into consideration. This incomplete understanding of OM breakdown hampers proper assessment of the present and past carbon cycle as well as the interpretation of OM based proxies and proxies affected by OM breakdown. To arrive at better proxy-based reconstructions "deformation functions" are needed, taking into account the transport and diagenesis-related molecular and atomic modifications following proxy formation. Some emerging proxies for OM degradation may shed light on such deformation functions. The use of palynomorph concentrations and selective changes in assemblage composition as models for production and preservation of OM may correct for bias due to selective degradation. Such quantitative assessment of OM degradation may lead to more accurate reconstruction of past productivity and bottom water oxygenation. Given the cost and effort associated with programs to recover sediment cores for paleoclimatological studies, as well as with generating proxy records, it would seem wise to develop a detailed sedimentological and diagenetic context for interpretation of these records. With respect to the latter, parallel acquisition of data that inform on the fidelity of the proxy signatures and reveal potential diagenetic biases would be of clear value.We acknowledge generous financial support by the DFG Research Center/Cluster of Excellence MARUM “The Ocean in the Earth System”, the International Graduate College EUROPROX and the Alfred Wegener Institute for Polar and Marine Research enabling the realisation of the “Workshop on Selective Preservation of Organic Matter: Processes and Impact on the Fossil Record” which formed the basis of this paper. GJMV acknowledges support by the German Science Foundation (DFG grant VE486/2)