Samuel Stylianos, Veloukas Thomas, Papavasileiou Antonios, Karaoglanidis George S
Aristotelian University of Thessaloniki, Faculty of Agriculture, Plant Pathology Laboratory, POB 269, 54124, Thessaloniki, Greece.
Plant Dis. 2012 Sep;96(9):1286-1290. doi: 10.1094/PDIS-01-12-0103-RE.
This study was conducted primarily to investigate the presence and frequency distribution of the transposable elements Boty and Flipper in populations of the necrotroph plant pathogen Botrytis cinerea in Greece. In total, 334 isolates were collected from diseased grape, strawberry, tomato, cucumber, kiwifruit, and apple fruit during 2009. The presence of the two transposable elements was based on polymerase chain reaction detection. Results showed that all the sampled hosts occurred in sympatry, with four possible different genotypes (transposa type carrying both transposable elements, Boty type carrying only the Boty element, Flipper type carrying only the Flipper element, and vacuma type carrying neither transposable element). Marked differences in genotype frequencies among populations were observed. In tomato, cucumber, grape, and strawberry, transposa isolates carrying both elements were predominant in the populations whereas, in kiwifruit and apple fruit populations, the vacuma isolates were prevailing. Furthermore, in kiwi and apple fruit populations, high frequencies of Flipper-type isolates were observed. In an attempt to explain the observed predominance of vacuma isolates in kiwifruit populations, the mycelial growth rate of a set of vacuma isolates was compared with the mycelial growth rate of a set of transposa isolates at three different temperatures (0, 10, and 20°C). The same set of isolates was used to compare pathogenicity of isolates on wound-inoculated kiwifruit incubated at two different temperatures (0 and 20°C), in terms of disease incidence and disease severity. In addition, the selected isolates were used to compare their ability in causing latent infections on kiwifruit in the field. The results showed that vacuma and transposa isolates had similar mycelial growth rates at the limiting temperatures of 0 and 10°C, while vacuma isolates grew faster at the optimum temperature of 20°C. Similarly, there was no significant difference regarding pathogenicity on kiwifruit between transposa and vacuma isolates. However, artificial inoculations conducted on blossoms in the field showed that vacuma isolates caused significantly higher incidence of latent infections.
本研究主要旨在调查希腊坏死型植物病原菌灰葡萄孢菌群体中转座元件Boty和Flipper的存在情况及频率分布。2009年期间，共从患病的葡萄、草莓、番茄、黄瓜、猕猴桃和苹果果实中收集了334个分离株。基于聚合酶链反应检测这两种转座元件的存在情况。结果表明，所有采样宿主均同域出现，有四种可能的不同基因型（携带两种转座元件的转座型、仅携带Boty元件的Boty型、仅携带Flipper元件的Flipper型以及不携带任何转座元件的空泡型）。观察到群体间基因型频率存在显著差异。在番茄、黄瓜、葡萄和草莓中，携带两种元件的转座型分离株在群体中占主导地位，而在猕猴桃和苹果果实群体中，空泡型分离株占优势。此外，在猕猴桃和苹果果实群体中，观察到Flipper型分离株的频率较高。为了解释在猕猴桃群体中空泡型分离株占优势的现象，将一组空泡型分离株的菌丝生长速率与一组转座型分离株在三个不同温度（0、10和20°C）下的菌丝生长速率进行了比较。使用同一组分离株比较了在两种不同温度（0和20°C）下接种伤口的猕猴桃上分离株的致病性，包括发病率和病情严重程度。此外，所选分离株用于比较它们在田间引起猕猴桃潜伏感染的能力。结果表明，在0和10°C的极限温度下，空泡型和转座型分离株的菌丝生长速率相似，而在20°C的最适温度下，空泡型分离株生长更快。同样，转座型和空泡型分离株对猕猴桃的致病性没有显著差异。然而，在田间对花朵进行的人工接种表明，空泡型分离株引起的潜伏感染发生率显著更高。
