Nothophaeocryptopus gaeumannii causes Swiss needle cast disease in Douglas‐fir forest trees and ornamental plantations. This study analysed disease and pathogen behaviour from summer 2011 to spring 2012. An untreated plot within a Pseudotsuga menziesii var. glauca plantation in Valle de Bravo, Mexico was divided into 12 sub‐plots. At each sampling date, needles were collected from four trees per sub‐plot. The analysis included seven needle age cohorts from branches from two canopy sections, as well as fallen needles from five random trees inside the entire plot. Airborne ascospores were collected weekly in slide traps. Sequencing identified the pathogen from DNA extracted from 18 mycelial colonies (isolates) and ascospores DNA from four selective slide traps. Disease and pathogen characteristics were mostly similar to other reports, except for ascospores inside pseudothecia on the youngest age class of foliage. Defoliation affected lower canopies frequently, while in the middle canopy it ranged from 6% to 98% depending on the needle age. In fallen needles, mature pseudothecia contained ascospores and isolated colonies developed in an agar‐based medium. Ascospore fluctuation peaked in two periods, but the most relevant occurred from 11 February to 17 March 2012, coinciding with bud break. These results contribute further understanding of SNC disease useful in improving the health of Christmas trees and the less‐studied P. menziesii var. glauca.

中文翻译：

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对瑞士假单胞菌变种瑞士针铸疾病的分析。墨西哥的一个圣诞树种植园内的glauca

高加索夜蛾（Nothophaeocryptopus gaeumannii）在花旗松林木和观赏人工林中引起瑞士针叶病。这项研究分析了2011年夏季至2012年春季的疾病和病原体行为。Pseudotsuga menziesii var中未经处理的地块。劳卡墨西哥Valle de Bravo的人工林分为12个子样地。在每个采样日期，从每个子图的四棵树中收集针叶。分析包括来自两个冠层部分的树枝的七个针头年龄队列，以及整个样地内五棵随机树的针头掉落。每周在载玻片收集器中收集空气中的子囊孢子。测序从从18个菌丝菌落（分离物）中提取的DNA和从四个选择性载玻片陷阱中提取的子囊孢子DNA中鉴定出病原体。病害和病原体特征与其他报道大部分相似，除了在最年轻的叶子年龄等级的假皮层中的子囊孢子。落叶经常影响下冠层，而在中冠层，取决于针头的年龄，其范围从6％到98％不等。在落针中 成熟的假鞘膜含有子囊孢子和在琼脂基培养基中形成的分离菌落。子囊孢子的波动在两个时期达到峰值，但最相关的是从2012年2月11日至3月17日，与芽断裂相吻合。这些结果有助于进一步了解SNC疾病，有助于改善圣诞树和未得到充分研究的圣诞树的健康。P.menziesii变种 劳卡。