Jaenike John
Department of Biology, University of Rochester, Rochester, NY, 14627.
Evolution. 1985 Nov;39(6):1295-1301. doi: 10.1111/j.1558-5646.1985.tb05695.x.
Approximately one-half of the members of the Drosophila quinaria species-group are mycophagous. The mushroom-breeding species D. falleni, D. recens, and D. phalerata are far more tolerant of the mushroom toxin α-amanitin than are D. guinaria, D. palustris, and D. subpalustris, which breed in decaying water plants. The non-mycophagous species, however, are physiologically capable of larval development in mushrooms, showing that high levels of amanitin tolerance are not necessary for mycophagy. A primary selective advantage of amanitin tolerance among the mycophagous species is that it allows them to breed in mushrooms that are toxic to nematodes that infest Drosophila in other fungi and render them infertile. Parasitism, then, may be an important factor governing evolutionary patterns of resource utilization in these species.
果蝇quinaria物种组中约一半的成员以真菌为食。以蘑菇为繁殖场所的物种，如D. falleni、D. recens和D. phalerata，比在腐烂水生植物中繁殖的D. guinaria、D. palustris和D. subpalustris对蘑菇毒素α-鹅膏菌素的耐受性要强得多。然而，不以真菌为食的物种在生理上也能够在蘑菇中进行幼虫发育，这表明对鹅膏菌素的高耐受性并非以真菌为食所必需。在以真菌为食的物种中，对鹅膏菌素耐受性的一个主要选择性优势在于，这使它们能够在对寄生在其他真菌中果蝇的线虫有毒并使其不育的蘑菇中繁殖。因此，寄生现象可能是支配这些物种资源利用进化模式的一个重要因素。
