Cocoa pod isolates of Phytophthora palmivora (Ppal) from different locations in Papua New Guinea (PNG) were grown in the presence of cellophane to determine their abilities to mechanically penetrate this barrier and to gain access to the growth media below. Four Ppal isolates, MAG14, MAG30, MAG50, NSP11 and the plant root pathogenic oomycete P. cinnamomi for comparison, were tested for their cellophane penetrating ability. All were able to penetrate the cellophane by forming appressoria and infection peg-like structures. All Ppal isolates formed frond-like structures which grew at various depths within the cellophane while P. cinnamomi formed hyphal aggregations and frond-like structures within the cellophane. This is the first in vitro study demonstrating how Ppal can modify its hyphal morphology to form lobed structures upon contact to the cellophane surface and branched aggregating hyphae within cellophane to gain access to growth media below.

中文翻译：

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使用玻璃纸研究棕榈疫霉 PNG 可可分离株的体外感染结构

来自巴布亚新几内亚 (PNG) 不同地点的棕榈疫霉 (Ppal) 的可可豆荚分离物在玻璃纸存在下生长，以确定它们机械穿透该屏障并获得下方生长介质的能力。测试了四种 Ppal 分离物 MAG14、MAG30、MAG50、NSP11 和用于比较的植物根病原性卵菌 P. cinnamomi 的玻璃纸穿透能力。所有这些都能够通过形成附着物和感染钉状结构来穿透玻璃纸。所有 Ppal 分离物都形成了在玻璃纸内不同深度生长的叶状结构，而肉桂在玻璃纸内形成了菌丝聚集体和叶状结构。