Phytopathology. 1998 Jan;88(1):39-44. doi: 10.1094/PHYTO.1998.88.1.39.
ABSTRACT The pathogenicity of two isolates of each of four bark beetle-associated blue-stain fungi was evaluated after mass inoculation of about 40-year-old Norway spruce trees (Picea abies). Trees were inoculated with a different isolate of each fungus in 1995 and 1996 at a density of 400 inoculations per m(2) in a 1.2-m-wide band on the lower bole (about 270 inoculations per tree). Trees were felled 15 weeks after inoculation. In 1995, Ceratocystis polonica was the only fungus that had stained the sapwood (56.3% of cross-sectional sapwood area). It induced five times longer phloem necroses, 21 times more dead cambium, and 11 times more dead phloem than any other fungus. In 1996, C. polonica induced less extensive host symptoms and an unidentified Ambrosiella sp. induced comparable symptoms to C. polonica in the phloem and cambium. No trees showed any foliar symptoms 15 weeks after inoculation, but six out of eight trees inoculated with C. polonica in 1995 had only 0 to 25% functional sapwood and probably would have died if felling had been delayed. This study confirms that C. polonica, an associate of the aggressive bark beetle Ips typographus, is pathogenic to Norway spruce. The pathogenicity of the Ambrosiella sp., which is associated with a nonaggressive bark beetle, seems moderate and varies between isolates. The two remaining fungi included in this study (Ophiostoma piceae and a dark fungus with sterile mycelium), which are associated with nonaggressive bark beetles, were nonpathogenic in both experiments. These results are consistent with the hypothesis that aggressive bark beetle species vector virulent fungi that may help them kill trees, but the results also show that some nonaggressive bark beetles may vector phytopathogenic fungi.
摘要 在大规模接种约 40 年生挪威云杉（Picea abies）后，评估了来自 4 种树皮甲虫伴生蓝变真菌的每个种的 2 个分离物的致病性。1995 年和 1996 年，在树干下部 1.2 米宽的条带上以每平方米 400 个接种点（每棵树约 270 个接种点）的密度，用每个种的不同分离物接种树木。接种后 15 周，树木被砍伐。1995 年，只有 Ceratocystis polonica 使边材变色（横截面边材面积的 56.3%）。它诱导的韧皮部坏死是其他任何真菌的 5 倍，形成的死亡形成层是其他任何真菌的 21 倍，死亡韧皮部是其他任何真菌的 11 倍。1996 年，C. polonica 引起的寄主症状较轻，一种未鉴定的 Ambrosiella sp. 在韧皮部和形成层中引起的症状与 C. polonica 相当。接种后 15 周，没有树木出现任何叶片症状，但 1995 年接种 C. polonica 的 8 棵树中的 6 棵仅有 0%至 25%的功能边材，如果延迟砍伐，它们可能会死亡。这项研究证实，与侵袭性树皮甲虫 Ips typographus 有关的 Ceratocystis polonica 对挪威云杉具有致病性。与非侵袭性树皮甲虫有关的 Ambrosiella sp. 的致病性似乎适中，并且在分离物之间有所不同。本研究中包括的另外两种真菌（Ophiostoma piceae 和一种无菌菌丝的暗真菌）与非侵袭性树皮甲虫有关，在这两项实验中均无致病性。这些结果与以下假设一致，即侵袭性树皮甲虫种类携带可能有助于其杀死树木的致病真菌，但结果也表明，一些非侵袭性树皮甲虫可能携带植物病原真菌。
