Tomlin Elizabeth S., Alfaro Rene I., Borden John H., He Fangliang
Centre for Pest Management, Department of Biological Sciences, Simon Fraser University, Burnaby, B.C. V5A 1S6, Canada.
Tree Physiol. 1998 Jan;18(1):21-28. doi: 10.1093/treephys/18.1.21.
The traumatic wound response of families of white spruce, Picea glauca (Moench) Voss, resistant or susceptible to the white pine weevil, Pissodes strobi (Peck), were compared after simulated weevil damage. Leaders from 331 trees were wounded just below the apical bud in the spring, coinciding with the natural time of weevil oviposition. A portable 1-mm diameter drill was used to drill 24 holes per leader. Leaders were removed in the fall and examined for evidence of traumatic resin canal formation. Drilled trees had a traumatic wound response 8 times greater than that of undrilled trees; however, undrilled trees also formed some resin canals in response to unknown causes. In the drilled trees, the traumatic wound response extended into the lower part of the leader, where it could possibly affect older larvae. Trees from resistant families responded with greater intensity than trees from susceptible families, by producing multiple rings of traumatic resin canals. Trees from resistant families also responded more rapidly than trees from susceptible families based on number of cells to the first ring of traumatic resin canals. Trees from some resistant families exhibited no traumatic resin canal formation, showing considerable within-family variation and suggesting that other resistance mechanisms might be important. In the year after drilling, there was a reduction in tree diameter growth and trees suffered a reduction in constitutive resin canals in the bark, which suggests some energetic cost of traumatic resin production. There was no indication that the extent of constitutive defenses, as measured by density of cortical resin canals before wounding, was related to the ability to produce traumatic resin canals. Screening trees based on their capacity to produce traumatic resin canals may be useful in selecting genotypes resistant to white pine weevil.
在模拟象鼻虫损害后，对白云杉（Picea glauca (Moench) Voss）抗或感白松象鼻虫（Pissodes strobi (Peck)）的家系的创伤伤口反应进行了比较。春季，在331棵树的顶芽下方刚好进行创伤处理，这与象鼻虫自然产卵时间一致。使用便携式直径1毫米的钻头，在每个主枝上钻24个孔。秋季移除主枝，检查创伤树脂道形成的证据。钻孔的树的创伤伤口反应比未钻孔的树大8倍；然而，未钻孔的树也因未知原因形成了一些树脂道。在钻孔的树中，创伤伤口反应延伸到主枝下部，在那里可能影响较老的幼虫。抗性家系的树比感病家系的树反应更强烈，产生多圈创伤树脂道。基于形成第一圈创伤树脂道的细胞数量，抗性家系的树也比感病家系的树反应更快。一些抗性家系的树没有表现出创伤树脂道形成，显示出相当大的家系内变异，这表明其他抗性机制可能很重要。钻孔后的一年，树的直径生长减少，树皮中的组成型树脂道数量减少，这表明创伤树脂产生存在一些能量成本。没有迹象表明，以受伤前皮层树脂道密度衡量的组成型防御程度与产生创伤树脂道的能力有关。基于产生创伤树脂道的能力筛选树木，可能有助于选择对白松象鼻虫具有抗性的基因型。
