针叶树病原菌异担子菌属的物种多样性及相关检疫建议

Diversity of Heterobasidion causing root and butt rotting of conifers and proposal for entry wood quarantine aiming at Heterobasidion species

异担子菌属Heterobasidion种类是北半球针叶树最严重的森林病原菌,在世界范围内能侵染27种针叶树,对欧洲和北美洲的经营林已造成重大损失。基于传统形态学研究,认为异担子菌属有2个种,即多年异担子菌H.annosum和岛生异担子菌H.insulare,然而单孢交配实验研究证明2个种为复合种。分子系统发育分析研究表明:异担子菌属包括15个种,其中5个种为森林病原菌[冷杉异担子菌H.abietinum、多年异担子菌(狭义)H.annosum s.str.、变孔异担子菌H.irregulare、西方异担子菌H.occidentale和小孔异担子菌H.parviporum];10个种为腐生菌(淀粉孢异担子菌H.amyloideum、南洋杉异担子菌H.araucariae、阿曼德异担子菌H.armandii、南方异担子菌H.australe、岛生异担子菌H.insulare、林芝异担子菌H.linzhiense、东方异担子菌H.orientale、拟岛生异担子菌H.subinsulare、拟小孔异担子菌H.subparviporum和西藏异担子菌H.tibeticum)。多年异担子菌(狭义)H.annosum s.str.、小孔异担子菌H.parviporum和冷杉异担子菌H.abietinum分布于欧洲,分别是松属、云杉属和冷杉属林木的病原菌。变孔异担子菌H.irregulare和西方异担子菌H.occidentale分布于北美洲,前者侵染松属和柏属树木,后者侵染冷杉属、铁杉属、黄杉属和巨杉属树木。虽然广义的多年异担子菌H.annosum sensu lato曾在我国报道,但基于目前研究结果表明该种为拟小孔异担子菌H.subparviporum。目前世界上最具侵染力的5种病原菌即狭义的多年异担子菌H.annosum s.str.、小孔异担子菌H.parviporum、冷杉异担子菌H.abietinum、变孔异担子菌H.irregulare和西方异担子菌H.occidentale还未在我国发现,也未列为对外检疫对象,因此建议将其列为进境植物检疫性有害生物。RNA聚合酶Ⅱ大亚基序列(RPB1)在异担子菌属种类鉴定中敏感性和特异性最高,研究证明该分子方法可应用于鉴别不同异担子菌种类的有效基因标记,在海关部门进行原木和木质产品的检疫中可运用该分子标记进行林木病原异担子菌的检测。

The species of Heterobasidion are the most aggressive pathogens in managed coniferous forests in North Hemisphere,which can infect 27 coniferous trees and cause severe damages to managed forest in Europe and North America.Two species,H.annosum and H.insulare,were recognized based on morphological study.However,the mating tests demonstrated that both taxa were complex.Recent studies show that 15 species are existed,including five pathogenetic species(H.abietinum,H.annosum s.str.,H.irregulare,H.occidentale and H.parviporum)and ten saprophytic species(H.amyloideum,H.araucariae,H.armandii,H.australe,H.insulare,H.linzhiense,H.orientale,H.subinsulare,H.subparviporum and H.tibeticum).H.annosum s.str.,H.parviporum and H.abietinum occur in Europe,and they are pathogens on Pinus,Picea and Abies,respectively;while H.irregulare and H.occidentale are distributed in North American,and the former infects Pinus and Juniperus and the latter attacks Abies,Tsuga,Pseudotsuga and Sequoiadendron.H.annosum sensu lato was previously reported in China,and it is revised as H.subparviporum based on current study.The most aggressive conifers’pathogens,H.annosum s.str.,H.parviporum,H.abietinum,H.irregulare and H.occidentale,are not found in China,and herein are proposed to be treated as wood quarantine fungi.RPB1 is the most sensitive molecular marker for identifying species of Heterobasidion,and it could be applied for logs and woody products quarantine in Chinese Customs.