Huang Shuang-Quan, Tang Lu-Lu, Yu Qian, Guo You-Hao
College of Life Sciences, Wuhan University, Wuhan 430072, China.
Evolution. 2004 May;58(5):1131-4. doi: 10.1111/j.0014-3820.2004.tb00446.x.
We tested one of the predictions of Brunet and Charlesworth (1995) that relative floral sex allocation will vary temporally with the mating environment and that the form of dichogamy (protandry vs. protogyny) will select for the pattern of variation in male versus female resource allocation. In many hermaphroditic plant species, allocation to female function (ovule number) decreases from early to late flowers within inflorescences as a result of resource limitation or ontogenetic changes. This pattern may obscure the effects of the mating environment and dichogamy on selection for allocation patterns in protandrous species (male allocation increases regardless). By examining a protogynous species the alternative pattern of temporal variation in resource allocation is predicted, namely that allocation to male function should decrease (or female allocation increase) throughout the flowering sequence. This pattern was observed in protogynous Aquilegia yabeana (Ranunculaceae), in which ovule number per flower remained constant whereas pollen number decreased in sequentially blooming flowers. These observations support the temporal sex allocation hypothesis of Brunet and Charlesworth (1995).
我们检验了布鲁内特和查尔斯沃思（1995年）的一项预测，即相对花性分配会随交配环境在时间上发生变化，并且雌雄异熟的形式（雄蕊先熟与雌蕊先熟）会选择雄性与雌性资源分配的变化模式。在许多雌雄同体的植物物种中，由于资源限制或个体发育变化，花序内从早期花到晚开花，分配给雌性功能（胚珠数量）会减少。这种模式可能会掩盖交配环境和雌雄异熟对雄蕊先熟物种中分配模式选择的影响（无论如何雄性分配都会增加）。通过研究一个雌蕊先熟的物种，预测了资源分配随时间变化的另一种模式，即整个开花序列中分配给雄性功能的应该减少（或雌性分配增加）。在雌蕊先熟的毛茛科植物华北耧斗菜中观察到了这种模式；在依次开放的花中，每朵花的胚珠数量保持不变，而花粉数量减少。这些观察结果支持了布鲁内特和查尔斯沃思（1995年）的时间性性别分配假说。
