Department of Entomology, Texas A&M University, College Station, TX, 77843-2475, USA.
Oecologia. 2013 Dec;173(4):1425-37. doi: 10.1007/s00442-013-2728-2. Epub 2013 Jul 19.
Plant defenses against herbivores are predicted to change as plant lineages diversify, and with domestication and subsequent selection and breeding in the case of crop plants. We addressed whether defense against a specialist herbivore declined coincidently with life history evolution, domestication, and breeding within the grass genus Zea (Poaceae). For this, we assessed performance of corn leafhopper (Dalbulus maidis) following colonization of one of four Zea species containing three successive transitions: the evolutionary transition from perennial to annual life cycle, the agricultural transition from wild annual grass to primitive crop cultivar, and the agronomic transition from primitive to modern crop cultivar. Performance of corn leafhopper was measured through seven variables relevant to development speed, survivorship, fecundity, and body size. The plants included in our study were perennial teosinte (Zea diploperennis), Balsas teosinte (Zea mays parviglumis), a landrace maize (Zea mays mays), and a hybrid maize. Perennial teosinte is a perennial, iteroparous species, and is basal in Zea; Balsas teosinte is an annual species, and the progenitor of maize; the landrace maize is a primitive, genetically diverse cultivar, and is ancestral to the hybrid maize; and, the hybrid maize is a highly inbred, modern cultivar. Performance of corn leafhopper was poorest on perennial teosinte, intermediate on Balsas teosinte and landrace maize, and best on hybrid maize, consistent with our expectation of declining defense from perennial teosinte to hybrid maize. Overall, our results indicated that corn leafhopper performance increased most with the agronomic transition, followed by the life history transition, and least with the domestication transition.
植物对草食动物的防御预计会随着植物谱系的多样化而发生变化，对于作物植物来说，还会随着驯化以及随后的选择和培育而发生变化。我们研究了玉米叶蝉（Dalbulus maidis）在禾本科玉米属（Zea）的四个物种中一个物种的定殖后，其防御能力是否会随着生活史进化、驯化和培育而下降。为此，我们评估了玉米叶蝉在以下四个物种中的表现：一个是具有三个连续过渡的多年生植物到一年生植物的进化过渡，一个是从野生一年生草本植物到原始作物品种的农业过渡，以及一个是从原始作物品种到现代作物品种的农业过渡。玉米叶蝉的表现通过七个与发育速度、存活率、繁殖力和体型相关的变量来衡量。我们的研究包括多年生大刍草（Zea diploperennis）、巴尔萨斯大刍草（Zea mays parviglumis）、一个地方品种玉米（Zea mays mays）和一个杂交玉米。多年生大刍草是一种多年生、多次生殖的物种，是玉米属中最基础的物种；巴尔萨斯大刍草是一种一年生物种，是玉米的祖先；地方品种玉米是一种原始的、遗传多样性丰富的品种，是杂交玉米的祖先；而杂交玉米是一种高度自交的、现代的品种。玉米叶蝉在多年生大刍草上的表现最差，在巴尔萨斯大刍草和地方品种玉米上的表现中等，在杂交玉米上的表现最好，这与我们预期的从多年生大刍草到杂交玉米的防御能力下降的情况一致。总的来说，我们的结果表明，玉米叶蝉的表现随着农业的过渡而增加最多，其次是生活史的过渡，而随着驯化的过渡而增加最少。
