Lempa K, Martel J, Koricheva J, Haukioja E, Ossipov V, Ossipova S, Pihlaja K
Section of Ecology, Department of Biology, and Kevo Subarctic Research Institute, University of Turku, FIN-20014 Turku, Finland e-mail:
Department of Chemistry, Laboratory of Physical Chemistry, University of Turku, FIN-20014, Turku, Finland, , , , , , FI.
Oecologia. 2000 Feb;122(3):354-360. doi: 10.1007/s004420050041.
Fluctuating asymmetry (FA) is used to describe developmental instability in bilateral structures. In trees, high FA of leaves has been assumed to indicate the level of environmental or genetic stress, and for herbivores leaves from such trees have been shown to be in some cases (though not invariably) of higher quality compared to trees with symmetrical leaves. We demonstrated that FA of birch leaves correlated positively with growth rate of leaves, and with the amount of leaf biomass consumed by larvae of the geometrid Epirrita autumnata. Since asymmetry per se cannot define leaf quality for a herbivore, we determined the biochemical compounds which covary with the degree of foliage FA, in order to elucidate relationships between leaf FA, chemistry and herbivory. High foliar FA was characteristic of birches with high initial concentrations, and rapid seasonal decline in the concentrations of gallic acid and hydrolysable tannins, and with rapid seasonal changes in the concentrations of flavonoid-glycosides and sugars. In contrast, leaf FA was not related to concentrations of proanthocyanidins, protein-bound amino acids or soluble phenylalanine, the precursor of proanthocyanidins and proteins with aromatic amino acids. The positive correlation between leaf FA and consumption by E. autumnata was presumably related to the previously demonstrated compensatory consumption of E. autumnata to high concentrations of foliar gallotannins. Furthermore, sugars are well-known feeding stimulants. We propose that the variable results in studies correlating leaf FA and herbivory may stem from variable chemical associations of FA in different plants and of species-specific effects of compounds on insects.
波动不对称性（FA）用于描述双侧结构中的发育不稳定性。在树木中，叶片的高FA被认为表明环境或遗传压力的程度，并且对于食草动物来说，与具有对称叶片的树木相比，来自此类树木的叶片在某些情况下（尽管并非总是如此）质量更高。我们证明了桦树叶的FA与叶片生长速率以及尺蛾Epirrita autumnata幼虫消耗的叶片生物量呈正相关。由于不对称性本身无法为食草动物定义叶片质量，我们确定了与叶片FA程度共变的生化化合物，以阐明叶片FA、化学性质和食草作用之间的关系。高叶片FA是初始浓度高、没食子酸和可水解单宁浓度季节性快速下降、黄酮糖苷和糖浓度季节性快速变化的桦树的特征。相比之下，叶片FA与原花青素、蛋白质结合氨基酸或可溶性苯丙氨酸（原花青素和含芳香族氨基酸蛋白质的前体）的浓度无关。叶片FA与Epirrita autumnata的消耗量之间的正相关可能与之前证明的Epirrita autumnata对高浓度叶片没食子单宁的补偿性消耗有关。此外，糖是众所周知的取食刺激物。我们认为，在将叶片FA与食草作用相关联的研究中，结果的差异可能源于不同植物中FA的可变化学关联以及化合物对昆虫的物种特异性影响。
