Agritrop
Home

How an improved sorghum variety evolves in a traditional seed system in Mali: Effects of farmers' practices on the maintenance of phenotype and genetic composition

Deu Monique, Weltzien-Rattunde Eva, Calatayud Caroline, Traoré Yalaly, Bazile Didier, Gozé Eric, Trouche Gilles, Vom Brocke Kirsten. 2014. How an improved sorghum variety evolves in a traditional seed system in Mali: Effects of farmers' practices on the maintenance of phenotype and genetic composition. Field Crops Research, 167 : pp. 131-142.

Journal article ; Article de revue à facteur d'impact
[img] Published version - Anglais
Access restricted to CIRAD agents
Use under authorization by the author or CIRAD.
document_573966.pdf

Télécharger (1MB)

Quartile : Q1, Sujet : AGRONOMY

Abstract : In Africa, it is mostly the informal seed system that ensures farmers' seed supply. This is partly because the formal seed systems are not always effective in meeting demand for new seed varieties. Sometimes informal seed recycling and exchange of improved sorghum varieties will take place alongside formal initiatives, as is the case in southern Mali. Focusing on one particular village in the Dioïla district, we analyze the efficacy of farmers' strategies for preserving varietal seed purity and genetic integrity of an improved inbred-line (Soumba variety). Six seed lots of Soumba, recycled for two to six years by farmers using different practices, were collected and assessed in on-station trials in order to compare their agronomic performance and phenotypic purity (off-type plant frequencies) with control versions of the variety. Additionally, 30 panicle samples were randomly collected from five farmer fields sown with recycled Soumba and assessed for phenotypic purity in a progeny nursery and investigated for molecular diversity using 12 SSR markers. A total of 150 panicles from five other non-Soumba varieties were collected in the village in order to investigate eventual gene flow and its potential genetic consequences for the Soumba variety. In fields sown with recycled Soumba seed, between 2% and 14% of plants showed phenotypic deviations from the typical Soumba variety. The progeny nursery and SSR marker analysis verified the presence of the off-type plants observed in the field. The STRUCTURE program revealed admixtures with other varieties in 23% of Soumba plants, confirming the presence of gene flow. Gene diversity values in Soumba samples ranged from 0.006 for the commercial sample to 0.257 for recycled samples. Introgression and contamination were best minimized when (1) farmers had received specific training in seed production, (2) they could take advantage of isolated fields and (3) they could practise true-to-type panicle selection. Farmerswere generally able to maintain the phenotype, as well as sustain or even improve yield performance of their Soumba variety while at the same time genetically enriching their seed stock. (Résumé d'auteur)

Mots-clés Agrovoc : Sorghum bicolor, Production de semences, Lignée pure, Variété, Conservation du matériel génétique, Amélioration des plantes, Phénotype, Secteur informel, Agriculteur, Technologie traditionnelle

Mots-clés géographiques Agrovoc : Mali

Classification Agris : F30 - Plant genetics and breeding
F03 - Seed production
P01 - Nature conservation and land resources

Champ stratégique Cirad : Axe 1 (2014-2018) - Agriculture écologiquement intensive

Auteurs et affiliations

  • Deu Monique, CIRAD-BIOS-UMR AGAP (FRA)
  • Weltzien-Rattunde Eva, ICRISAT (MLI)
  • Calatayud Caroline, CIRAD-BIOS-UMR AGAP (FRA)
  • Traoré Yalaly, ULPC (MLI)
  • Bazile Didier, CIRAD-ES-UPR GREEN (FRA) ORCID: 0000-0001-5617-9319
  • Gozé Eric, CIRAD-PERSYST-UPR AIDA (FRA) ORCID: 0000-0001-9121-7835
  • Trouche Gilles, CIRAD-BIOS-UMR AGAP (FRA)
  • Vom Brocke Kirsten, CIRAD-BIOS-UMR AGAP (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/573966/)

View Item (staff only) View Item (staff only)

[ Page générée et mise en cache le 2020-10-09 ]