Analysis of Ustilago scitaminea genetic diversity using microsatellite markers provides evidence of selfing and dispersal of a unique lineage over America and Africa

Raboin Louis-Marie, Selvi Athiappan, Miranda Oliveira K., Paulet Florence, Calatayud Caroline, Zapater Marie-Françoise, Brottier Philippe, Garsmeur Olivier, Carlier Jean, D'Hont Angélique. 2006. Analysis of Ustilago scitaminea genetic diversity using microsatellite markers provides evidence of selfing and dispersal of a unique lineage over America and Africa. In : VIIIth ISSCT Pathology Workshop Petit-Bourg, Guadeloupe (FWI), 23-27 January 2006, programme and abstracts. Daugrois Jean-Heinrich. ISSCT, CIRAD-CA. Réduit : ISSCT, Résumé ISSCT Pathology Workshop. 8, Petit-Bourg, Guadeloupe, 23 Janvier 2006/27 Janvier 2006.

Résumé : Ustilago scitaminea Sydow, which causes sugarcane smut disease, has been spreading throughout Africa and America since the 1950s. The objectives of the present study were (1) to confirm and further describe the global population structure of U. scitaminea on the basis of a larger number of isolates and (2) to infer its reproduction system. Microsatellite markers, that present the advantage of being highly polymorphic, PCR-based, reproducible and codominant, were therefore developed for U. scitaminea and used to analyse a sample of single-teliospore isolates from various sugarcane-producing countries around the world. We surveyed 142 single-spore isolates of Ustilago scitaminea for genetic diversity. The fungal samples were teliospores from 77 single whips (sori) collected on various cultivars and at different locations in 15 sugarcane-growing countries throughout the world. The overall genetic structure of this fungus was investigated using 17 polymorphic microsattelite loci. All isolates but one were homozygous for all loci, indicating that selfing could be the highly preferential predominant reproductive mode of U. scitaminea. In America and Africa, genetic diversity was found to be extremely low and all isolates belonged to a single inbred lineage. This inbred lineage was also found in some parts of the Asian continent where most U. scitaminea genetic diversity was detected. These observations support the hypothesis that the fungus originated in Asia. The strong founder effect observed in the global genetic structure of U. scitaminea suggests that the fungus migrated from Asia to other continents on rare occasions. (Texte intégral)

Mots-clés Agrovoc : Saccharum, Ustilago scitaminea, variation génétique, charbons, technique analytique, marqueur génétique, PCR

Mots-clés géographiques Agrovoc : Afrique, Asie, Amériques

Classification Agris : H20 - Maladies des plantes
F30 - Génétique et amélioration des plantes

Auteurs et affiliations

• Raboin Louis-Marie, CIRAD-AMIS-UMR PVBMT (REU)
• Selvi Athiappan, Sugarcane Breeding Institute (IND)
• Miranda Oliveira K., UNICAMP (BRA)
• Paulet Florence, CIRAD-CA-DIR (FRA)
• Calatayud Caroline, CIRAD-AMIS-UMR PIA (FRA)
• Zapater Marie-Françoise, CIRAD-AMIS-UMR BGPI (FRA)
• Brottier Philippe, Centre national de séquençage (FRA)
• Garsmeur Olivier, CIRAD-AMIS-UMR PIA (FRA) ORCID: 0000-0001-8869-3689
• Carlier Jean, CIRAD-AMIS-UMR BGPI (FRA) ORCID: 0000-0002-6967-1852
• D'Hont Angélique, CIRAD-AMIS-UMR PIA (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/534823/)

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