Geographic patterns of seed mass are associated with climate factors, but relationships vary between species
Geographic patterns of seed mass are associated with climate factors, but relationships vary between species
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DOI：
10.3732/ajb.1500295
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发表时间：
2016-01-01
影响因子：
3
通讯作者：
Etterson, Julie R.
中科院分区：
文献类型：
--
作者：
Gorden, Nicole L. Soper;Winkler, Katharine J.;Etterson, Julie R.
研究的前提：种子大小是一个关键的生活史属性，其适应性影响贯穿植物的整个生命周期。种间研究反复报告种子质量和纬度之间的负相关性。然而，尽管它的重要性，鲜为人知的是，在物种的范围内的种子大小的地理变异的方法：为了提高我们的理解种内的地理变异的种子大小，我们收集和称重种子的母系从8至17人口的7个草本植物物种跨越大的地理区域，并测量了两个草种的传播特性，芒长。我们研究了种子质量和纬度之间的整体关系，然后将数据划分为特定物种的子集，以比较三个模型的拟合来解释种子质量和芒长度：（1）纬度和经度，（2）长期气候，（3）收集年weather.KEY结果：像以前的工作一样，我们发现种间种子质量和纬度之间存在负相关关系。然而，解释种子大小和芒长的最佳拟合模型不同的个别物种，往往包括显着的相互作用条款。对于所有物种，最好的模型是长期或收集年的气候数据，而不是纬度和longitudines.CONCLUSIONS：种内的地理格局种子性状显着不一致，协变负和正与温度和降水。唯一明显的概括是，一年生种的种子质量对应更多的采集年的天气，而多年生植物的协变与长期气候。总的来说，这项研究表明，塑造种子性状的气候变化的规模是高度物种特异性的。
PREMISE OF THE STUDY: Seed size is a critical life history attribute with fitness effects that cascade throughout the lifespan of plants. Interspecific studies repeatedly report a negative correlation between seed mass and latitude. Yet, despite its importance, little is known about geographic variation in seed size within species' ranges.METHODS: To improve our understanding of intraspecific geographic variation in seed size, we collected and weighed seeds by maternal line from 8 to 17 populations of seven herbaceous plant species spanning large geographic areas, and measured a dispersal trait, awn length, for two grass species. We examined the overall relationship between seed mass and latitude, then divided the data into species-specific subsets to compare the fit of three models to explain seed mass and awn length: (1) latitude and longitude, (2) long-term climate, and (3) collection-year weather.KEY RESULTS: Like previous work, we found a negative relationship between interspecific seed mass and latitude. However, the best-fit models explaining seed size and awn length differed between individual species and often included significant interaction terms. For all species, the best model was either long-term or collection-year climate data instead of latitude and longitude.CONCLUSIONS: Intraspecific geographic patterns for seed traits were remarkably inconsistent, covarying both negatively and positively with temperature and precipitation. The only apparent generalization is that annual species' seed mass corresponded more with collection-year weather while perennial species covaried more with long-term climate. Overall, this study suggests that the scale of climate variation that molds seed traits is highly species-specific.