落叶松八齿小蠹伴生真菌3个菌株的鉴定及生物学生理学特性

Identification and Biological and Physiological Characteristics of 3 Fungus Strains Associated with Ips subelongatus

从落叶松八齿小蠹各虫态体内外、坑道及木材蓝变部位获得3株与落叶松八齿小蠹伴生的真菌,该3株菌可导致木材变色,与蠹害的发生存在密切关系。通过菌体的培养特性和形态观察、放线菌酮耐性及rDNAITS序列测定,将3菌株确认为Ceratocystis fujiensis,为国内新记录种。3个菌株生长的最佳环境条件:温度为25℃,光照为全黑暗条件,pH值为5.0;最佳营养条件:培养基为PDA+落叶松韧皮培养基,碳源为蔗糖,氮源为酵母粉。3个菌株均具有较强的高温和低温耐受性,能够适应北方较大的温差,树体内的黑暗和酸性条件也比较适合菌株的生长。3个菌株对寄主落叶松具有明显的营养选择性,可利用的碳源种类较多,有机氮源利于菌株生长。

Three fungal strains associated with Ips subelongatus were isolated from the blue-stain tissue,inside and surface of the body of Ips subelongatus.The fungal stains can cause wood sapstains which associate with the bark beetle attacks.According to culture and morphology characteristic,cycloheximide tolerance and rDNA ITS molecular sequence,the three strains were identified as Ceratocystis fujiensis M.J.Wingf.which is a new record species in China.The optimum conditions for strains growth were as follows：temperature was at 25 ℃,in complete dark,with pH value 5.0,medium was PDA plus larch phloem extract,supplemented with carbon source of sucrose and nitrogen source of yeast.The three strains had strong tolerance to high and low temperature,so the strains were able to adapt to the larger temperature scale in the north.Dark and acidic conditions in trees were suitable for the growth of strains.C.fujiensis was highly selective to host larch nutrition,and the strains could utilize many kinds of carbon source,but preferred organic nitrogen source.