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''Phellinus pini'' (current name: ''Porodaedalea pini'' (Brot.) Murrill 1905) is a fungal plant pathogen that causes tree disease commonly known as "red ring rot" or "white speck." This disease, extremely common in the conifers of North America, decays tree trunks, rendering them useless for lumber.〔(Red Ring Rot - Field Guide to Insects and Diseases of AZ and NM Forests )〕 It is a rot of the heartwood. Signs of the fungus include shelf-shaped conks protruding from the trunks of trees. Spores produced on these conks are blown by the wind and go on to infect other trees.〔(Decays )〕 Formal management of this disease is limited, and the disease is controlled primarily by cultural practices. Red ring rot is an important forest disturbance agent and plays a key role in habitat formation for several forest animals. == Hosts and symptoms == Red ring rot is common in North America. The pathogen ''Phellinus pini'' is widely spread in the temperate zone in the Northern Hemisphere. It infects a wide range of coniferous trees, including jack pine, lodgepole pine, Sitka and white spruce, Douglas-fir, balsam and true fir, western hemlock, and tamarack.〔(Red Ring Rot ).〕〔(Forest Disease Management Notes ).〕 It attacks both heartwood and sapwood and causes white pocket trunk rot. The basidiocarps (fruiting body), conks, are the most apparent signs on infected trees. The conks are perennial, usually gregarious, imbricate, and shelve-shaped, about 3 inches wide.〔 The tops of conks are reddish brown to blackish with concentric furrows; the underside is yellow-brown, while for growing conks, the undersurface and margin of growing conks is a bright yellowish-brown with large irregular pores. White pockets usually develop where the conks develop, but the decay may extend 4 ft above and 5 ft below a conk. Decay tends to occur at the base of stem, but may also develop into large roots.〔 In the early stage of decay, the affected wood becomes reddish to purplish in color. A cross section of the affected wood shows a well-defined ring. In advanced stages of decay, small, spindle-shaped white pockets are formed due to the degradation of lignin by ''P. pini''. The white pockets are mostly hollow and delignified and contain white residual cellulose.〔 ''On Engelmann spruce'' ''P. pini'' is the most common pathogen to Engelmann spruce (''Picea engelmannii'') and causes the largest decay columns. There is red staining in the early stages and tends to develop a long the annual rings. The decay can be identified with white pockets and punk knots (a slight swollen, resinous knot) and conks. Decay usually occurs mostly in the basal stem and may extend to roots. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Phellinus pini」の詳細全文を読む スポンサード リンク
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