广西高峰林场相思树的真菌病害调查

相思树是从澳大利亚引进的速生丰产林种,在广西以高峰林场为主要种植基地。经初步调查,不同相思树上发生的真菌性病害不同,马占相思树、厚荚相思树、直干相思树、纹英相思树、杂交相思发生炭疽病,其病原茵为胶孢炭疽菌(Colletotrichum gloeosporioides),在马占相思、直干相思、纹荚相思和杂交相思的叶片上只产生病原菌的无性阶段,而在厚荚相思叶片上可同时出现无性阶段和有性阶段;马占相思树和杂交相思树上发生的白粉病菌为白粉菌Oidium sp．,其中杂交相思白粉病发生普遍而严重,发病期多在3-5月;黑木相思树发生叶尖枯病,病原为异色拟盘多毛孢(Pestalotiopsis versicolor),一年四季均可发病;马占相思树干基部心腐病发生严重,造成木材的大量损失,病原尚未得到确定。本文对病害的症状特点、病原菌形态特征进行了描述。

A Survey of Fungal Diseases of Acacia Cultivated in Guangxi Gaofeng Forest Farm

Acacia spp.,which are fast-growing trees introduced from Australia,have been successfully planted in Guangxi Gaofeng Forest Farm,a major Acacia planting base in China.A preliminary survey of fungal diseases on Acacia was made from December 2004 to May 2006.The result showed that anthrac- nose(Colletotrichum gloeosporioides)was a common leaf disease of Acacia mangium,A.crassicarpa, A.auriculiformis,A.aulatocarpa and hybridized Acacia(A.mangium×A.auriculiformis),which occurred all the year round.The pathogen produced asexual and sexual stages on leaves of A.crassicarpa and only formed asexual stage on other Acacia species.Powdery mildew(Oidium sp.)of A.mangium and hybridized Acacia(A.mangium×A.auriculiformis)was prevalent from March to May and it was more serious on hybridized Acacia than on A.mangium.Pestalotiopsis versicolor caused leaf-tip blight of Acacia melanoxylon.The heart rot occurred seriously on main stem of A.mangium,causing serious timber damage,however its pathogens have not been identified yet.The symptoms of these diseases and morphological characters of pathogens were described.