Ethnolinguistic structuring of sorghum genetic diversity in Africa and the role of local seed systems

Westengen, Ola Tveitereid; Okongo, Mark Atam; Onek, L. A.; Berg, Trygve; Upadhyaya, Hari D.; Birkeland, Siri; Khalsa, Siri Dharma Kaur; Ring, Kristoffer Hofaker; Stenseth, Nils Chr.; Brysting, Anne K.

doi:10.1073/pnas.1401646111

Cited by 56 publications

(54 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a previous study, we analyzed the relationship between sorghum genetic diversity patterns and the organization of rural societies at the local scale and found that different ethnolinguistic groups living in the same locality grow different landraces (5). At the country scale, Deu and colleagues (6) observed that sorghum genetic patterns coincide with major ethnolinguistic groups, and similar patterns have been observed at the broader scale of African linguistic families (7,8).…”

mentioning

confidence: 84%

“…It has been shown to induce human genetic differentiation by limiting gene flows among ethnolinguistic groups (37,38), as well as to maintain cultural differentiation by limiting the dissemination of knowledge and practices between geographically close groups (39,40). In the same way, patrilocal residence and ethnolinguistic endogamy, driving homophilous seed exchanges, explain the relationship between ethnolinguistic diversity and crop diversity patterns that has notably been observed on country and continental scales for sorghum (6,7), pearl millet (41), cassava, and taro (3,42). Thus, considering seed exchanges as major gene flow drivers, the effect of farmers' social exchange networks on crop diversity dynamics can be interpreted in terms of evolutionary forces.…”

Section: Effect Of Residential and Ethnolinguistic Homophily On Seed mentioning

confidence: 98%

See 1 more Smart Citation

Seed exchange networks, ethnicity, and sorghum diversity

Labeyrie

Thomas

Muthamia

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

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.crop diversity dynamics | local seed systems | social organization | social networks analysis | exponential random graph models

show abstract

mentioning

confidence: 84%

Section: Effect Of Residential and Ethnolinguistic Homophily On Seed mentioning

confidence: 98%

Seed exchange networks, ethnicity, and sorghum diversity

Labeyrie

Thomas

Muthamia

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Seed exchange among farmers of the same ethnic group may have contributed in shaping this genetic structure (Barnaud, Trigueros, McKey, & Joly, 2008;Orozco-Ramírez et al, 2016;Pressoir & Berthaud, 2004). Codiffusion of sorghum with human migration has been demonstrated at Africa-wide scale (Westengen et al, 2014) and at a regional scale in Kenya (Labeyrie, Thomas, Muthamia, & Leclerc, 2016). Durra sorghum in Senegal are grown mainly by the Fulani ethnic group, so the clustering of Senegalese durra with Ethiopian durra ( Figure S2d) and low F ST (0.052) suggest that durra sorghums moved with Fulani people from northeast Africa (Scheinfeldt, Soi, & Tishkoff, 2010).…”

Section: Distribution and Diffusion Of Ethnic Groups In Senegal Inclumentioning

confidence: 99%

Genomic signatures of adaptation to Sahelian and Soudanian climates in sorghum landraces of Senegal

Faye

Maina

et al. 2019

Ecology and Evolution

View full text Add to dashboard Cite

Uncovering the genomic basis of climate adaptation in traditional crop varieties can provide insight into plant evolution and facilitate breeding for climate resilience. In the African cereal sorghum (Sorghum bicolor L. [Moench]), the genomic basis of adaptation to the semiarid Sahelian zone versus the subhumid Soudanian zone is largely unknown. To address this issue, we characterized a large panel of 421 georeferenced sorghum landrace accessions from Senegal and adjacent locations at 213,916 single‐nucleotide polymorphisms (SNPs) using genotyping‐by‐sequencing. Seven subpopulations distributed along the north‐south precipitation gradient were identified. Redundancy analysis found that climate variables explained up to 8% of SNP variation, with climate collinear with space explaining most of this variation (6%). Genome scans of nucleotide diversity suggest positive selection on chromosome 2, 4, 5, 7, and 10 in durra sorghums, with successive adaptation during diffusion along the Sahel. Putative selective sweeps were identified, several of which colocalize with stay‐green drought tolerance (Stg) loci, and a priori candidate genes for photoperiodic flowering and inflorescence morphology. Genome‐wide association studies of photoperiod sensitivity and panicle compactness identified 35 and 13 associations that colocalize with a priori candidate genes, respectively. Climate‐associated SNPs colocalize with Stg3a, Stg1, Stg2, and Ma6 and have allelic distribution consistent with adaptation across Sahelian and Soudanian zones. Taken together, the findings suggest an oligogenic basis of adaptation to Sahelian versus Soudanian climates, underpinned by variation in conserved floral regulatory pathways and other systems that are less understood in cereals.

show abstract

“…Lastly, on a wider spatiotemporal scale, past human migrations have also largely contributed to present‐day diversity patterns, as was remarkably highlighted for sorghum across Africa (Westengen, Okongo, et al., ), for the diffusion of banana from New‐Guinea to West Africa (Perrier et al., ), of maize in the Americas (Vigouroux et al., ), and of sweet potato from South America to Polynesia (Roullier, Benoit, McKey, & Lebot, ).…”

Section: Introductionmentioning

confidence: 99%

Past and present dynamics of sorghum and pearl millet diversity in Mount Kenya region

Labeyrie

Deu

Dussert

et al. 2016

Evolutionary Applications

View full text Add to dashboard Cite

Crop populations in smallholder farming systems are shaped by the interaction of biological, ecological, and social processes, occurring on different spatiotemporal scales. Understanding these dynamics is fundamental for the conservation of crop genetic resources. In this study, we investigated the processes involved in sorghum and pearl millet diversity dynamics on Mount Kenya. Surveys were conducted in ten sites distributed along two elevation transects and occupied by six ethnolinguistic groups. Varieties of both species grown in each site were inventoried and characterized using SSR markers. Genetic diversity was analyzed using both individual‐ and population‐based approaches. Surveys of seed lot sources allowed characterizing seed‐mediated gene flow. Past sorghum diffusion dynamics were explored by comparing Mount Kenya sorghum diversity with that of the African continent. The absence of structure in pearl millet genetic diversity indicated common ancestry and/or important pollen‐ and seed‐mediated gene flow. On the contrary, sorghum varietal and genetic diversity showed geographic patterns, pointing to different ancestry of varieties, limited pollen‐mediated gene flow, and geographic patterns in seed‐mediated gene flow. Social and ecological processes involved in shaping seed‐mediated gene flow are further discussed.

show abstract

Ethnolinguistic structuring of sorghum genetic diversity in Africa and the role of local seed systems

Cited by 56 publications

References 54 publications

Seed exchange networks, ethnicity, and sorghum diversity

Seed exchange networks, ethnicity, and sorghum diversity

Genomic signatures of adaptation to Sahelian and Soudanian climates in sorghum landraces of Senegal

Past and present dynamics of sorghum and pearl millet diversity in Mount Kenya region

Contact Info

Product

Resources

About