Osier Tod L, Lindroth Richard L
Department of Entomology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, USA.
Oecologia. 2004 Mar;139(1):55-65. doi: 10.1007/s00442-003-1481-3. Epub 2004 Jan 23.
This research tested the long-term effects of defoliation on aspen chemistry and growth in relation to genotype and nutrient availability. We grew saplings of four aspen genotypes in a common garden under two conditions of nutrient availability, and subsequently subjected them to two levels of artificial defoliation. Artificial defoliation suppressed plant growth, and saplings of the four genotypes did not show evidence of genetic variation in tolerance to defoliation. Phenolic glycoside concentrations did not respond to defoliation, but were influenced by genotype and nutrient availability. Condensed tannins responded to defoliation and varied among genotypes. Although defoliation affected condensed tannins, plant quality was not altered in a manner important for gypsy moth performance. Regression analyses suggested that phenolic glycoside concentrations accounted for most of the variation in insect performance. The lack of a strong response important for herbivores was surprising given the severity of the defoliation treatment (nearly 100% of leaf area was removed). In this study, plant genotype was of primary importance, nutrient availability was of secondary importance and long-term induced responses were unimportant as determinants of insect performance.
本研究测试了去叶处理对杨树化学性质和生长的长期影响，及其与基因型和养分有效性的关系。我们在养分有效性的两种条件下，于一个共同园圃中培育了四种杨树基因型的树苗，随后对它们进行了两种程度的人工去叶处理。人工去叶抑制了植物生长，四种基因型的树苗在对去叶的耐受性方面未表现出遗传变异的迹象。酚糖苷浓度对去叶处理无响应，但受基因型和养分有效性的影响。缩合单宁对去叶处理有响应，且在不同基因型间存在差异。尽管去叶处理影响了缩合单宁，但植物质量并未以对舞毒蛾表现至关重要的方式发生改变。回归分析表明，酚糖苷浓度占昆虫表现变异的大部分。鉴于去叶处理的严重程度（几乎去除了100%的叶面积），对食草动物而言缺乏强烈响应令人惊讶。在本研究中，植物基因型最为重要，养分有效性次之，长期诱导反应作为昆虫表现的决定因素并不重要。
