RUI: The Ecological Consequences of Sexual and Apomictic Reproduction

实验测试将使用一种高山植物>Antennaria> >parvifolia>进行。天线虫是进行这些测试的理想动物，因为种群由两种个体组成，它们在形态上相似，但在繁殖方式上不同。有些植物是有性的，需要花粉来使它们的种子受精，并产生基因可变的后代。另一些是无性繁殖（无生殖），不需要花粉，产生基因相同的后代。在一些地方，这两种类型在母羊种群中共存；在其他地方，只有一种或另一种存在。在混合种群中，这两种类型的成年个体几乎同样常见。然而，正如预测的那样，无性雌性的种子产量超过有性雌性的两倍。因此，这个实验系统集中体现了我们试图解释的悖论：为什么性个体在生产上处于劣势时却如此普遍？除了增加我们对一种非常基本的生物现象的理解之外，这项工作还可以应用于农业和林业。农业植物在遗传上通常是同质的，在这些遗传上同质的植物中，可能也存在与>天线虫>无性繁殖有关的任何缺点。研究结果可能会导致对农业系统设计的建议，这些系统可能会减少成功所需的化肥和农药投入的数量。

Experimental tests will be carried out using an alpineplant, >Antennaria> >parvifolia>. >Antennaria> is ideal for carryingout these tests, because populations consist of two kinds ofindividuals, morphologically similar but differing in their modeof reproduction. Some plants are sexual, requiring pollen tofertilize their seeds, and producing genetically variableoffspring. Others are asexual (apomictic), requiring no pollenand producing genetically identical offspring. At some sites,both types coexist in the dame populations; at others, only onetype or the other is present. In mixed populations, adultindividuals of the two types are about equally common. However,the seed production of asexual females exceeds that of sexualfemales by a factor of two, as predicted. Thus, thisexperimental system epitomizes the paradox we seek to explain:why are sexual individuals so common when they have areproductive disadvantage? In addition to increasing our understanding of a very basicbiological phenomenon, this work also has applications foragriculture and forestry. Agricultural plantings are typicallygenetically homogeneous, and any disadvantages associated withasexual reproduction in >Antennaria> may also exist in thesegenetically uniform plantings. Research findings may lead torecommendations for the design of agricultural systems that mightreduce the amount of fertilizer and pesticide inputs necessaryfor success.