Harrington Thomas C, Huang Qiong, Ferreira Maria A, Alfenas Acelino C
Department of Plant Pathology and Microbiology, Iowa State University, Ames 50014.
College of Plant Protection, Yunnan Agricultural University, Kunming, 650201, China.
Plant Dis. 2015 Jan;99(1):106-111. doi: 10.1094/PDIS-01-14-0056-RE.
Genotypes of the Latin American wilt pathogen Ceratocystis fimbriata have been moved around the world in vegetatively propagated material of various crop plants, including Ipomoea batatas (sweet potato), Colocasia esculenta (taro), and Eucalyptus spp. When compared to a worldwide collection of isolates of C. fimbriata, isolates from taro, Punica granatum (pomegranate), and Eriobotrya japonica (loquat) from Yunnan Province, China were found to have sequences of internal transcribed spacer (ITS) rDNA and mating type genes that were identical to isolates from Eucalyptus in Brazil. Analyses of 35 isolates with 14 microsatellite markers revealed that the Yunnan population was nearly uniform, consisting of only 19 alleles and seven closely related genotypes, suggesting that the population is not natural and is the result of an introduction. As in comparisons of sequences of ITS rDNA and mating type genes, the microsatellite alleles of the Yunnan isolates were most similar to those of Eucalyptus isolates from Minas Gerais and Bahia, Brazil, where C. fimbriata is native, soilborne, and commonly infects cuttings of Eucalyptus spp. used for rooting in nurseries. Thus, the Yunnan population, which is causing severe losses on pomegranate, may have been indirectly derived from introductions of C. fimbriata in contaminated Eucalyptus cuttings from Brazil.
拉丁美洲枯萎病病原菌——帚状炭疽菌的基因型，已通过包括甘薯、芋头和桉树等多种作物的无性繁殖材料传播到世界各地。与全球范围内收集的帚状炭疽菌分离株相比，来自中国云南省芋头、石榴和枇杷的分离株，其内部转录间隔区（ITS）核糖体DNA和交配型基因序列，与巴西桉树分离株的序列相同。对35个分离株进行14个微卫星标记分析发现，云南群体几乎是同质的，仅由19个等位基因和7个密切相关的基因型组成，这表明该群体并非自然形成，而是引入的结果。如同ITS核糖体DNA和交配型基因序列比较一样，云南分离株的微卫星等位基因与巴西米纳斯吉拉斯州和巴伊亚州桉树分离株的等位基因最为相似，在巴西，帚状炭疽菌是本土土壤传播的，常感染用于苗圃扦插生根的桉树种条。因此，在石榴上造成严重损失的云南群体，可能间接来源于从巴西受污染的桉树插条引入的帚状炭疽菌。
