Raboin Louis-Marie, Selvi Athiappan, Oliveira Karine Miranda, Paulet Florence, Calatayud Caroline, Zapater Marie-Françoise, Brottier Philippe, Luzaran Rosalyn, Garsmeur Olivier, Carlier Jean, D'Hont Angélique
CIRAD (Centre de coopération internationale en recherche agronomique pour le développement), UMR PVBMT, Pôle de Protection des Plantes, Ligne Paradis, 97410 Saint-Pierre, Réunion, France.
Fungal Genet Biol. 2007 Jan;44(1):64-76. doi: 10.1016/j.fgb.2006.07.004. Epub 2006 Sep 18.
The basidiomycete Ustilago scitaminea Sydow, which causes sugarcane smut disease, has been spreading throughout Africa and America since the 1940s. The genetic diversity and structure of different populations of this fungus worldwide was investigated using microsatellites. A total of 142 single-teliospore were isolated from 77 distinct whips (sori) collected in 15 countries worldwide. Mycelium culture derived from on generation of selfing of these single teliospores were analysed for their polymorphisms at 17 microsatellite loci. All these strains but one were homozygous at all loci, indicating that selfing is likely the predominant reproductive mode of U. scitaminea. The genetic diversity of either American or African U. scitaminea populations was found to be extremely low and all strains belong to a single lineage. This lineage was also found in some populations of Asia, where most U. scitaminea genetic diversity was detected, suggesting that this fungal species originated from this region. The strong founder effect observed in U. scitaminea African and American populations suggests that the fungus migrated from Asia to other continents on rare occasions through movement of infected plant material.
担子菌纲真菌甘蔗黑粉菌（Ustilago scitaminea Sydow）可引发甘蔗黑穗病，自20世纪40年代以来一直在非洲和美洲蔓延。利用微卫星对该真菌在全球不同种群的遗传多样性和结构进行了研究。从全球15个国家收集的77个不同病鞭（孢子堆）中总共分离出142个单担孢子。对这些单担孢子自交一代产生的菌丝体培养物进行了17个微卫星位点的多态性分析。除一个菌株外，所有这些菌株在所有位点均为纯合子，这表明自交可能是甘蔗黑粉菌的主要繁殖方式。研究发现，美洲或非洲的甘蔗黑粉菌种群的遗传多样性极低，所有菌株都属于单一谱系。在亚洲的一些种群中也发现了这一谱系，亚洲检测到了大多数甘蔗黑粉菌的遗传多样性，这表明该真菌物种起源于该地区。在非洲和美洲的甘蔗黑粉菌种群中观察到的强烈奠基者效应表明，这种真菌很少通过感染植物材料的移动从亚洲迁移到其他大陆。
