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Recent studies investigating the relationship between crop genetic diversity and human cultural diversity patterns showed that seed exchanges are embedded in farmers’ social organization. However, our understanding of the social processes involved remains limited. We investigated how farmers’ membership in three major social groups interacts in shaping sorghum seed exchange networks in a cultural contact zone on Mount Kenya. Farmers are members of residence groups at the local scale and of dialect groups clustered within larger ethnolinguistic units at a wider scale. The Chuka and Tharaka, who are allied in the same ethnolinguistic unit, coexist with the Mbeere dialect group in the study area. We assessed farmers’ homophily, propensity to exchange seeds with members of the same group, using exponential random graph models. We showed that homophily is significant within both residence and ethnolinguistic groups. At these two levels, homophily is driven by the kinship system, particularly by the combination of patrilocal residence and ethnolinguistic endogamy, because most seeds are exchanged among relatives. Indeed, residential homophily in seed exchanges results from local interactions between women and their in-law family, whereas at a higher level, ethnolinguistic homophily is driven by marriage endogamy. Seed exchanges and marriage ties are interrelated, and both are limited between the Mbeere and the other groups, although frequent between the Chuka and Tharaka. The impact of these social homophily processes on crop diversity is discussed.

When attempting to land on a ship deck tossed by the sea, helicopter pilots must make sure that the helicopter can develop sufficient lift to be able to safely touchdown. This reminder of affordance theory led us to model and study the affordance of deck-landing-ability, which defines whether it is possible to land safely on a ship deck depending on the helicopter's available lift and the ship’s deck heave movements. Two groups of participants with no piloting experience using a laptop helicopter simulator attempted to land either a low-lifter or a heavy-lifter helicopter on a virtual ship deck by either triggering a pre-programmed lift serving as the descent law if it was deemed possible to land, or aborting the deck-landing maneuver. The deck-landing-ability was manipulated by varying the helicopter's initial altitude and the ship's heave phase between trials. We designed a visual augmentation making visible the deck-landing-ability, and thus enabling participants to maximize the safety of their deck-landing attempts and reduce the number of unsafe deck-landing. The visual augmentation presented here was perceived by participants as a means of facilitating this decision-making process. The benefits were found to have originated from the clear-cut distinction it helped them to make between safe and unsafe deck-landing windows and the display of the optimal time for initiating the landing.

In the current polycrisis era, plant science, particularly when applied to agronomy, becomes instrumental: because our main substantial and renewable resource is plant biomass, many future solutions will depend on our ability to grow and transform plant material in a sustainable way. This also questions the way we conduct plant research and thus quantitative plant biology. In response to the increasing polarization between science and society, participatory plant research offers a pertinent framework. Far from moving away from quantitative approaches, participatory plant research builds on complexity associated with biology and situated knowledge. When researchers and citizens work together on societal issues, such friction becomes more fertile, quantitative questions become more complex, societal issues are addressed at their roots and outcomes often exceed that of top-down strategies. This article serves as an introduction to this ongoing bifurcation in plant science, using plant breeding as a key example.

Seed circulation among farmers, which is embedded in composite social networks, is a key process in the dynamics of seed systems that shape crop diversity. We analyzed the daily circulation of biological objects, i.e., cultivated plants (31 species, 284 landraces), within a community of first-generation migrants (16 households, 30 persons) living on the island of Vanua Lava in the South Pacific archipelago nation of Vanuatu. By combining participant observation, ethnobiological inventories, and social network analysis, we investigated how farmer social status and plant biocultural value affect plant circulation. Plant biocultural value was estimated by referring to their local classification according to uses, cultivation practices, growing environments, and biological properties. An aggregate plant circulation network (577 events) and three subnetworks (i.e., for starchy, side dish, or snack food categories) sharing the same 30 nodes were analyzed using exponential random graph models. Evidence that farmer social status influences the patterns of plant circulation was found through the distribution of structural parameters of the network, including: dyadic reciprocity; in-degree, out-degree, and their correlation; triadic cycling; and transitivity. At the scale of the aggregate network, direct or indirect reciprocity was not observed. Instead, a high out-degree (i.e., being a more frequent giver) and a negative correlation between in-degree and out-degree both confer prestige and reinforce hierarchy. These results suggest that some of the social dynamics of the Melanesian-type Big Man political system may persist, even though the system itself no longer exists in traditional form. Moreover, based on our comparative analysis of the three subnetworks, farmer social status appears to influence greatly the circulation of plants with high biocultural value while having little influence on plants with low biocultural value. Farmer social status and plant biocultural value (following their local classification) are important factors for understanding the social rules shaping seed circulation.

A molecularly imprinted polymer of Tenofovir (1), an FDA-approved acyclic nucleoside phosphonate with antiviral activity, was synthesized using a non-covalent approach. A pre-polymerization complex was formed between (1) and DMAEMA and in-house synthetic N1-[(2-methacryloyloxy)ethyl] thymine, with EGDMA as a cross-linker in an MeCN/H2O (9:1, 1:1) mixture as a porogen, giving an imprinting factor (IF) of 5.5 at 2.10−5 mol/L. Binding parameters were determined by the Freundlich–Langmuir model, Qmax and Ka, and well as the particle morphology for MIP and NIP. Finally, the release profiles, for MIP and NIP, were obtained at 25 °C and 37 °C, which is body temperature, in a phosphate buffer saline, pH 7.4, mimicking the blood pH value, to determine the potential sustained release of our polymeric materials.

Biodiversity-based agriculture is the main form of agriculture practiced by smallholder farmers, who produce half the world’s food, especially in the Global South. This form of agriculture relies on planned biodiversity intentionally managed by farmers and on the associated biodiversity that spontaneously colonizes the agroecosystem. In recent decades, there have been increasing calls from researchers and society to support biodiversity-based agriculture as an alternative paradigm to today’s industrial agriculture. Building adapted governance and management systems for enhancing farmers’ access to agrobiodiversity is a key challenge for the development of biodiversity-based agriculture. To achieve this, a better understanding of how farmer’s access agrobiodiversity is needed, and in particular, how this access is affected by interactions between farmers and with institutions, i.e., social networks. In this article, we first review the literature on the role of social networks in farmers’ access to agrobiodiversity, in the form of crop diversity and associated biodiversity, and the related knowledge to manage this diversity. This review points at a major knowledge gap concerning how the composition and structure of these networks affect farmers’ access to agrobiodiversity. Then, we review literature on social-ecological networks to identify how this framework developed for environmental management could contribute in getting a better understanding of the role of social networks’ structure and composition in farmers’ access to agrobiodiversity. Based on this review, we propose a social-ecological network framework dedicated to crop diversity. Finally, we present potential applications of this framework to develop new participatory approaches for agrobiodiversity management and governance, adapted to biodiversity-based agriculture.

As the effects of climate change begin to be felt on yield stability, it is becoming essential to promote the use of genetic diversity in farmers’ fields. The presence of genetic variability in variety could fulfil this purpose. Indeed, the level of intra-varietal genetic diversity influences the spatio-temporal stability of yields and the disease susceptibility of crop species. Breeding history of varieties and their management practices are two factors that should influence intra-varietal genetic diversity. This paper describes the genetic diversity of eight wheat samples covering a gradient from modern single varieties to on-farm mixtures of landraces. This gradient discriminates between landrace, historical and modern varieties, considering the breeding history of varieties, between single-varieties and mixtures of varieties, and between ex situ and in situ de facto strategy in terms of management practices. Genetic diversity of these samples was analyzed with the help of 41 single nucleotide polymorphism markers located in neutral regions, through computing genetic indices at three different levels: Allelic, haplotypic and genetic group level. Population structure and kinship were depicted using discriminant analysis and kinship network analysis. Results revealed an increase in the complexity of the genetic structure as we move on the gradient of variety types (from modern single variety to in situ on-farm mixtures of landraces). For the landraces, the highest levels of genetic diversity have been observed for a landrace (Solina d’Abruzzo) continuously grown on-farm in the region of Abruzzo, in Italy, for many decades. This landrace showed an excess of haplotypic diversity compared to landraces or the historical variety that were stored in genebanks (ex situ conservation). Genetic analyses of the mixtures revealed that, despite a very high selfing rate in wheat, growing in evolutionary mixtures promotes recombination between different genetic components of the mixture, a second way to increase the level of haplotype diversity. When management practices such as growing in mixture and on-farm management are combined, they substantially increase the different levels of genetic diversity of the populations (allelic, haplotypic, genetic group diversity), and consequently promote their adaptability. Our results confirm the need to develop and manage evolving diversified large populations on-farm. These results invite crop diversity managers such as genebank curators, community seed bank managers and farmers’ organizations to adapt their management strategies to the type of variety they wish to manage, because we have shown that their choices have a strong influence on the genetic composition of the crop populations.

Analysis of seed exchange networks at a single point in time may reify sporadic relations into apparently fixed and long-lasting ones. In northern Cameroon, where environment is not only strongly seasonal but also shows unpredictable interannual variation, farmers’ social networks are flexible from year to year. When adjusting their strategies, Tupuri farmers do not systematically solicit the same partners to acquire the desired propagules. Seed acquisitions documented during a single cropping season may thus not accurately reflect the underlying larger social network that can be mobilized at the local level. To test this hypothesis, we documented, at the outset of two cropping seasons (2010 and 2011), the relationships through which seeds were acquired by the members of 16 households in a Tupuri community. In 2011, farmers faced sudden failure of the rains and had to solicit distant relatives, highlighting their ability to quickly trigger specific social relations to acquire necessary seeding material. Observing the same set of individuals during two successive years and the seed sources they solicited in each year enabled us to discriminate repeated relations from sporadic ones. Although farmers did not acquire seeds from the same individuals from one year to the next, they relied on quite similar relational categories of people. However, the worse weather conditions during the second year led to (1) a shift from red sorghum seeds to pearl millet seeds, (2) a geographical extension of the network, and (3) an increased participation of women in seed acquisitions. In critical situations, women mobilized their own kin almost exclusively. We suggest that studying the seed acquisition network over a single year provides a misrepresentation of the underlying social network. Depending on the difficulties farmers face, they may occasionally call on relationships that transcend the local relationships used each year.

Carotenogenesis has been extensively studied in fruits and flower petals. Transcriptional regulation is thought to be the major factor in carotenoid accumulation in these organs. However, little is known about regulation in root organs. The root carotenoid content of carrot germplasm varies widely. The present study was conducted to investigate transcriptional regulation of carotenoid biosynthesis genes in relation to carotenoid accumulation during early carrot root development and up to 3 months after sowing. HPLC carotenoid content analysis and quantitative RT-PCR were compared to quantify the expression of eight genes encoding carotenoid biosynthesis enzymes during the development of white, yellow, orange, and red carrot roots. The genes chosen encode phytoene synthase (PSY1 and PSY2), phytoene desaturase (PDS), ζ-carotene desaturase (ZDS1 and ZDS2), lycopene ε-cyclase (LCYE), lycopene β-cyclase (LCYB1), and zeaxanthin epoxidase (ZEP). All eight genes were expressed in the white cultivar even though it did not contain carotenoids. By contrast with fruit maturation, the expression of carotenogenic genes began during the early stages of development and then progressively increased for most of these genes during root development as the total carotenoid level increased in coloured carrots. The high expression of genes encoding LCYE and ZDS noted in yellow and red cultivars, respectively, might be consistent with the accumulation of lutein and lycopene, respectively. The results showed that the accumulation of total carotenoids during development and the accumulation of major carotenoids in the red and yellow cultivars might partially be explained by the transcriptional level of genes directing the carotenoid biosynthesis pathway.

This paper rethinks the governance of genebanks in a social and political context that has significantly evolved since their establishment. The theoretical basis for the paper is the commons conceptual framework in relation to both seed and plant genetic resources. This framework is applied to question the current policy ecosystem of genetic research and breeding and explore different collective governance models. The concept of crop diversity management system (CDMS) commons is proposed as the new foundation for a more holistic and inclusive framework for crop diversity management, that covers a broad range of concerns and requires different actors. The paper presents a multi-stakeholder process established within the context of the two recent projects CoEx and Dynaversity, imagining possible collective arrangements to overcome existing deadlocks, foster collective learning, and design collaborative relationships among genebanks, researchers, and farmers’ civil society organizations involved in crop diversity management.