Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
Phytopathology. 2011 Aug;101(8):1005-12. doi: 10.1094/PHYTO-01-11-0015.
Ceratocystis wilt on eucalyptus, caused by Ceratocystis fimbriata, was first recognized in 1997 in the state of Bahia, Brazil, but is now known in five other states and in four other countries. C. fimbriata is a native, soilborne pathogen in some parts of Brazil but we hypothesized that genotypes of the pathogen have been moved among plantations in rooted cuttings collected from diseased trees and within plantations on cutting tools. We used six microsatellite markers to identify 78 genotypes of C. fimbriata among 177 isolates from individual trees in 20 eucalyptus plantations. The highest gene and genotypic diversity values were found in plantations on formerly wild Cerrado forest in Minas Gerais, suggesting that the fungus was in the soil prior to planting eucalyptus. In contrast, one or only a few genotypes were found in plantations on previous pastureland (with no woody hosts) in Bahia and São Paulo, and most of these genotypes were found in a Bahian nursery or in one of two Bahian plantations that were sources for rooted cuttings. Sources of cuttings tended to be dominated by one or a few genotypes that may have been spread within the plantation on cutting tools.
桉树尾孢枯萎病由尖孢镰刀菌引起，于 1997 年在巴西巴伊亚州首次被发现，但现在已知在另外五个州和四个其他国家也有发生。尖孢镰刀菌在巴西的一些地区是一种土传病原，但我们假设病原体的基因型已通过从患病树木中采集的插条和种植园中用于切割的工具在种植园中传播。我们使用了六个微卫星标记，在来自 20 个桉树种植园的 177 个单株分离物中鉴定出了 78 种尖孢镰刀菌基因型。在米纳斯吉拉斯州的曾经是野生塞拉多森林的种植园中发现了最高的基因和基因型多样性值，这表明真菌在种植桉树之前就在土壤中存在。相比之下，在巴伊亚州和圣保罗州的曾经的牧场上（没有木本宿主）的种植园中只发现了一种或少数几种基因型，而这些基因型大多存在于巴伊亚州的苗圃或两个巴伊亚种植园中，这两个种植园是插条的来源。插条的来源往往由一种或几种基因型主导，这些基因型可能已在种植园中通过切割工具传播。
