Decay process of wood of Japanese white birch [Betula platyphylla Sukaczev var. japonica (Miq.) H. Hara] tree by Inonotus obliquus (Fr.) Pilát was clarified by using the regression model in wood color and chemical components as a function of height position (1, 2, 3, and 4 m above the ground), wood type (sound wood and decayed wood), and their interactions, and anatomical observations. The 3 m height position, at which a sclerotium of I. obliquus was found, showed the highest decayed area percentage among four height positions. By the results of two-way analysis of variance, wood type affected all color indice. In addition, all factors (height position, wood type, and their interaction) were significant in all wood chemical components except for Klason lignin and hemicellulose. In the wood of the reaction zone, some substances were formed in the lumens of many vessels and a few wood fibers. Based on the results, we proposed the decay process of I. obliquus in naturally grown Japanese white birch, and the proposed process will contribute to a full understanding of the interactions between I. obliquus and Japanese white birch in the future.

中文翻译：

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阐明日本日光自然生长的白桦中桦褐孔菌的腐烂过程

日本白桦木材的腐烂过程[白桦苏卡泽夫变种粳稻(Miq.) H. Hara] 树 by桦褐孔菌（Fr.）Pilát 通过使用木材颜色和化学成分的回归模型作为高度位置（距地面 1、2、3 和 4 m）、木材类型（完好木材和腐烂木材）和它们的相互作用和解剖观察。3m高位置，菌核I. 斜肌发现，在四个高度位置中显示出最高的腐烂面积百分比。从双向方差分析的结果来看，木材类型对所有颜色指数都有影响。此外，除克拉森木质素和半纤维素外，所有因素（高度位置、木材类型及其相互作用）在所有木材化学成分中均显着。在反应区的木材中，许多血管的管腔和少量的木纤维中形成了一些物质。根据结果​​，我们提出了衰减过程I. 斜肌在自然生长的日本白桦中，所提出的过程将有助于充分理解之间的相互作用I. 斜肌以及未来的日本白桦。