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题目材料：
Domesticated crops have long been observed to differ strongly from their wild progenitors in morphological traits (form and structure). The enlargement of specific plant structures is the most widely emphasized of all of the changes that arise from domestication. Striking examples of gigantism can be found by comparing crops such as tomato (Lycopersicum esculentum), maize (Zea mays), beans (Phaseolus vulgaris), artichokes Cynara cardunculus var. scolymus), sunflower (Helianthus annuus), and squash (Cucurbita pepo) with their wild ancestors. The plant vigor hypothesis proposed by Price predicts that insect herbivores will tend to oviposit [lay eggs] on plant organs that grow faster and larger. Researchers found some support for this idea. For instance, in domesticated sunflowers, increased flower size from domestication is positively correlated with landing and egg-laying effort of female sunflower moths, Homoeosoma electellum, but increased seed size is negatively associated with parasitoid accessibility to H. electellum larvae. As a result, selection for gigantism may interfere with natural control and explain the observation that H. electellum is parasitized less frequently in sunflower agroecosystems than in natural sunflower ecosystems. However, parasitoids have a slightly greater effect on the banded sunflower moth, Cochylis hospes, which has a life history similar to that of H.electellum. Therefore, the life history of natural enemies and herbivores may influence whether selection for gigantism could result in enemy- whether selection for gigantism could result in enemy free space for herbivores.
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主旨题-转向
主旨题-转向
以上解析由 考满分老师提供。
