Garbelotto M, Smith T, Schweigkofler W
Department of Enivormental Science, Policy, and Management, Universityof California, Berkeley 94720, USA.
Phytopathology. 2008 Jan;98(1):137-43. doi: 10.1094/PHYTO-98-1-0137.
Patterns of spore deposition by Fusarium circinatum, the causal agent of pine pitch canker (PPC) of Monterey pine (Pinus radiata) and other conifers, were studied between May 2003 and April 2004 at two sites in Northern California using a novel spore trapping method combined with a real-time polymerase chain reaction (PCR) approach. At each study site, two plots were sampled by placing spore traps at 100 m intervals along transects 600 m in length. The air was sampled continuously by exchanging the spore traps every 2 weeks. The spore deposition rate (DR), ranged from 0 to 1.3 x 10(5) spores m(2). Spores were detected throughout the year, with higher trapping frequencies (TF) during the rainy season (November to April), than during the dry season (May to October). The detection of spores on traps at distances larger than 200 m from any Monterey pine, suggests at least midrange aerial dispersal. Finally, different inoculum loads were associated with trees displaying different levels of disease symptoms, suggesting infectiousness of the pathogen varies as the disease progresses. This study represents one of the first documenting continuous inoculum pressure values over an entire year for a forest pathogen, and provides important epidemiological information that will be invaluable in the development of disease progression models.
2003年5月至2004年4月期间，在加利福尼亚州北部的两个地点，采用一种新型孢子捕获方法结合实时聚合酶链反应（PCR）方法，研究了辐射松（Pinus radiata）和其他针叶树松脂溃疡病（PPC）的致病因子——轮状镰刀菌（Fusarium circinatum）的孢子沉积模式。在每个研究地点，沿着600米长的样带，每隔100米放置孢子捕获器，对两个样地进行采样。每2周更换一次孢子捕获器，对空气进行连续采样。孢子沉积率（DR）范围为0至1.3×10⁵个孢子/平方米。全年均检测到孢子，雨季（11月至4月）的捕获频率（TF）高于旱季（5月至10月）。在距离任何辐射松超过200米的捕获器上检测到孢子，表明至少存在中等距离的空中传播。最后，不同的接种量与显示不同疾病症状水平的树木相关，表明病原体的传染性随疾病进展而变化。这项研究是首批记录森林病原体全年连续接种压力值的研究之一，并提供了重要的流行病学信息，这对于疾病进展模型的开发将是非常宝贵的。
