Isolation of Staining Fungi from Jack Pine Trees‪.‬

Abstract This study was conducted to isolate wood staining fungi from standing trees of jack pine (Pinus banksiana Lamb.) to investigate whether species of Ceratocystis and Ophiostoma are associated with living trees. Two media were used for isolation, and a total of 532 fungal cultures were isolated from bark and sapwood of four freshly cut jack pine log sections. The most frequently isolated staining fungi were Hormonema dematioides Lagerberg & Melin, Aureobasidium pullulans (de Bary) Arnaud, and a Leptographium species. Re-inoculation of these three fungi into fresh jack pine billets showed that all these fungi caused stain in jack pine wood. However, all these species grow relatively slowly, especially in the tangential and radial directions of the billets. Comparing stain growth rates of these three fungi, established that H. dematioides grew the fastest, followed by Leptographium sp. A. pullulans grew the slowest on jack pine billets among the three species. The results indicated that none of the well known staining fungi such as Ceratocystis coerulescens (Munch) Bakshi, Ophiostoma minus (Hedgcock) H. & P. Sydow, O. piceae (Munch) H. & P. Sydow, or O. piliferum (Fries) H. & P. Sydow was associated with healthy living jack pine trees. Prompt transportation of logs from forests to sawmills, as well as a sanitary treatment of log storage yards, may help to reduce the severity of log stain before sawing.