Investigation of functional rhizo-biocomplex on highly adverse soil-adapting plants and application of the functional rhizo-biocomplex to agro-technology.

利用印度尼西亚加里曼丹中部当地泥炭土，对一株腐生土壤真菌青霉菌Y-1进行了种子萌发促进活性试验。用Y-1菌接种后种子萌发良好，但在当地泥炭土床上孵育1个月后幼苗全部死亡。只有将未灭菌的当地土壤悬浮液上清再接种到苗床上，接种Y-1的发芽苗才能存活并正常生长6个月以上。这表明腐生真菌促进种子萌发，而一些土壤细菌为发芽的幼苗提供养分。另一方面，在西伯利亚针叶林床土中，贫营养型伯克霍尔德菌和假单胞菌占据了土壤菌群，在10 ~ 15℃、较低碳源浓度（0.02 ~ 0.05%）下，它们表现出较高的乙炔还原活性。包括培养基pH在内，这些土壤细菌对适合多年冻土的培养条件具有高度的适应性，因此在夏季类似于活化多年冻土的理化条件下，土壤细菌的固氮活性相对较高。此外，结冷胶作为凝胶基质使细菌表现出最大的固氮潜力。在北海道乌苏山新积累的火山灰土积累极端土壤土地的野外条件下，该土地允许先锋植物具有菌根共生体并生长优势。特别是柳树树苗具有基本的外生菌根真菌，而草食性杂草，除了马尾和芦苇，允许与丛枝菌根真菌共生。结果表明，乌苏里山新鲜火山灰土壤中分布的先锋植物依赖于菌根感染。

Using local peat soil from Central Kalimantan, Indonesia, a saprophytic soil fungus Penicillium sp. Isolate Y-1 from X. complanata seedbed was tested its seed-germination promotion activity. The seeds germinated well by means of inoculation with Y-1 fungus, but the resulting seedlings were all died after one month-incubation in the local peat soil bed. Only when the supernatant of the local soil suspension without sterilization was further inoculated to the seedbeds, the germinated seedlings that had been inoculated with Y-1 resulted in survival and normal growth of the seedlings over 6 month. This suggested that saprophytic fungi stimulate seed germination, while some soil bacteria provide nutrients to the germinated seedlings. On the other hand, in Siberian Taiga forest bed soil, oligotrophic Burkholderia and Pseudomonas occupied soil microflora, and they showed a relatively high acetylene reduction activity at 10-15℃,under a lower concentration of carbon source (0.02-0.05%). Including medium pH, these soil bacteria were highly adapted to culture conditions agreeable to the permafrost soil, so that physicochemical conditions similar to activated permafrost soil in summer seasons resulted in relatively higher nitrogen-fixing activity. Moreover, gellan gum as gel matrix allowed the bacteria to show maximal nitrogen-fixing potential. Under a field condition of newly accumulated volcanic ash soil accumulated extreme soil land in Mt. Usu, Hokkaido, the land allowed pioneer plants to possess mycorrhizal symbionts and grew dominantly. Particularly, those of willow tree saplings constitutively possessed ectomycorrhizal fungi, while herbivorous weeds, except horsetail and rasp, allowed symbiosis with arbuscular mycorrhizal fungi. Thus, it was found that pioneer plants distributing throughout fresh volcanic ash soil in Mt. Usu were dependent on mycorrhizal infection.