The Pigment-Labeling Method: Calibrating the Method and Understanding its Limitations

P.I.： 格里克 提案编号：95- 04117 项目摘要 为了了解世界海洋初级生产的控制，浮游植物生物量和初级生产的变化必须被理解为物理，化学和生物参数的函数。 理想的情况是，初级生产力可以确定为浮游植物类群特定生物量和生长速率的乘积之和。 虽然 这 方法 目前 不 如果可能的话，浮游植物的生物量和生长率可以用十年前引进的叶绿素标记法来测量。 原则上，分类单位比生长速率也可以由类胡萝卜素的14 C标记确定。 然而，这些潜在的强大的方法一直在有限的基础上使用，因为缺乏对所测量的内容的机械理解。 本研究将对氮限制下连续培养的微藻在恒定光照条件下叶绿素a和类胡萝卜素的~（14）C标记动力学进行研究，以扩展前人的研究成果 到其他类胡萝卜素，藻类， 和营养有限的生长条件。 该研究还将确定色素标记动力学在藻类生长下的昼夜光周期和藻类生长辐照度的变化，以评估该方法的局限性时，它是在不均匀的生长条件下进行。 这项研究的结果将有助于研究社区的其他成员在解释的色素标记实验。

P.I.: Goericke Proposal #: 95- 04117 PROJECT ABSTRACT To understand the controls of primary production in the world ocean, variations of phytoplankton biomass and primary production must be understood as a function of physical, chemical and biological parameters. Ideally, one would determine primary production as the sum of the products of phytoplankton taxon specific biomass and growth rates. Although this approach is currently not possible, phytoplankton biomass and growth rates can be measured using the chlorophyll-labeling method, which as introduced a decade ago. Taxon specific growth rates can, in principle, also be determined from the 14C labeling of carotenoids. However, these potentially powerful methods have been used on a limited basis because a mechanical understanding of what is being measured was lacking. This research will study the 14C labeling kinetics of chlorophyll a and carotenoids in nitrogen limited continuous cultures of microalgae grown under constant light to extend previous research to other carotenoids, groups of algae, and conditions of nutrient-limited growth. The study will also determine pigment-labeling kinetics in algae grown under a diel photocycle and algae subject to growth irradiance changes to assess the limitations of the method when it is performed under conditions of uneven growth. The results of this study will aid other members of the research community in the interpretation of the pigment labeling experiments.