Performance of Pinus contorta inoculated with two strains of root endophytic fungus, Phialocephala fortinii:: effects of synthesis system and glucose concentration
Performance of Pinus contorta inoculated with two strains of root endophytic fungus, Phialocephala fortinii:: effects of synthesis system and glucose concentration
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DOI：
10.1139/cjb-76-7-1205
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发表时间：
1998-07-01
期刊：
影响因子：
--
通讯作者：
Trappe, JM
中科院分区：
文献类型：
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作者：
Jumpponen, A;Trappe, JM
黑化的根部定植真菌随处可见。然而，人们对它们的生态作用知之甚少，对这些真菌与其潜在寄主植物之间关系的研究结果也存在争议。研究这种联系的培养系统也可能影响寄主-真菌的相互作用。通过两个试验研究了黄山松与油松的关联性。和根部内生真菌Phialocephala fortinii Wang&Wilcox，研究寄主对接种的反应。首先，在无菌条件下，将两个品系接种于无菌条件下，在5个葡萄糖浓度的条件下生长。采用多元线性回归分析研究了接种量和葡萄糖浓度对菌体生长的影响。其次，在盆栽条件下，将相同的两株赤霉菌接种于红松苗木上。在无菌培养系统中，接种使寄主植物的所有生物量成分显著增加。例如，接种菌株1和菌株2的苗木总生物量分别增加约60%和90%。接种真菌培养6个月后，未观察到幼苗死亡。接种使寄主生物量随葡萄糖浓度的增加而增加，而不加接种物时，葡萄糖浓度对寄主生物量的影响不显著。接种降低了叶片中的氮磷浓度。葡萄糖浓度对叶片养分浓度的影响在两个菌株之间有所不同。在露地盆栽中，接种不影响生物量或叶片养分浓度。我们假设，在无菌培养系统中观察到的宿主生长的增加是由于封闭培养系统中的真菌呼吸，真菌提供给宿主植物的碳水化合物，或者最有可能是这两个因素的组合。讨论了无菌培养的生态学作用和无菌培养方法的有效性。
Melanized, root-colonizing fungi are ubiquitous. Their ecological role, however, is poorly understood, and results of studies of associations between these fungi and their potential host plants are controversial. The culture system under which the association is studied may also affect the host-fungus interaction. Two experiments on the association between Pinus contorta Dougl. ex Loud., and a root-inhabiting endophytic fungus, Phialocephala fortinii Wang & Wilcox, were conducted to study the host response to inoculation. First, Pinus contorta seedlings were inoculated with two strains of Phialocephala fortinii and grown under aseptic conditions with five levels of glucose in the medium. Multiple linear regression analysis was employed to study the effects of inoculation and glucose concentration. Second, the same two strains of Phialocephala fortinii were inoculated on Pinus contorta seedlings in open pot cultures. Inoculation resulted in substantial increase in all biomass components of the host plant in the aseptic culture system. Total biomass, for example, was increased approximately 60 and 90% when seedlings were inoculated with strain 1 and strain 2, respectively. No seedling mortality was observed following fungal inoculation after 6 months of incubation. Inoculation increased host biomass with increasing glucose concentration, while glucose concentration did not significantly affect host biomass when no inoculum was added. Inoculation lowered foliar nitrogen and phosphorus concentrations. The effect of glucose concentration on the foliar nutrient concentrations varied between the two strains. In the open pot cultures, inoculation did not affect biomass or foliar nutrient concentration. We hypothesise that the observed increases in host growth in the aseptic culture system are due to fungal respiration in a closed culture system, the carbohydrates made available to the host plant by the fungus, or, most likely, to a combination of both factors. The ecological role of Phialocephala fortinii and the validity of aseptic culture assays are discussed.