Several cyanobacteria, including diazotrophic Raphidiopsis raciborskii, can form harmful blooms when dissolved inorganic phosphorus (DIP) concentrations are very low. We hypothesized that R. raciborskii strains would vary in P allocations to cell growth and storage, providing resilience of populations to continuously low or variable P supplies. We tested this hypothesis using six toxic strains (producing cylindrospermopsins) isolated from a field population using batch monocultures with and without P and dissolved inorganic nitrogen (DIN). Treatments replete with DIN, irrespective of P addition, had similar exponential growth rates for individual strains. P storage capacity varied four-fold among strains and was significantly higher in DIN free treatments than in replete treatments. P was stored by all R. raciborskii strains, in preference to allocation to increase growth rates. P stores decreased with increased growth rate across strains but were not related to the time to P starvation in P free treatments. The storage capacity of R. raciborskii, combined with strategies to efficiently uptake P, mean that P controls may not control R. raciborskii populations in the short-term. Intra-population strain variation in P storage capacity will need to be reflected in process-based models to predict blooms of R. raciborskii and other cyanobacteria adapted to low-P conditions.

中文翻译：

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淡水蓝藻Raphidiopsis raciborskii的磷存储策略中的种群内菌株变异。

当溶解的无机磷（DIP）浓度非常低时，包括重氮营养的Raphidiopsis raciborskii在内的几种蓝细菌都可能形成有害的水华。我们假设，R。raciborskii菌株在磷分配中对细胞生长和贮藏的影响会有所不同，从而为种群提供了持续低磷或可变磷供应的适应力。我们使用六种有毒菌株（生产cysdrodrospermopsins）对这一假设进行了测试，这些菌株是使用具有和不具有P和溶解性无机氮（DIN）的批量单培养从田间种群中分离得到的。不论添加何种P，都充分补充DIN的处理对单个菌株而言具有相似的指数增长率。磷的贮藏能力在菌株之间变化了四倍，并且在无DIN处理中显着高于全处理。P被所有R.raciborskii菌株储存，优先分配以增加增长率。磷的贮藏随着菌株间生长速率的增加而降低，但与无磷处理中磷饥饿的时间无关。R. raciborskii的储存能力，再加上有效吸收P的策略，意味着P控制在短期内可能无法控制R. raciborskii种群。需要在基于过程的模型中反映种群内磷贮藏能力中的菌株变异，以预测R. raciborskii和其他适应低磷条件的蓝细菌的繁殖。raciborskii种群在短期内。在基于过程的模型中需要反映种群内磷贮藏能力中的菌株变异，以预测R.raciborskii和其他适应低磷条件的蓝细菌的繁殖。raciborskii种群在短期内。在基于过程的模型中需要反映种群内磷贮藏能力中的菌株变异，以预测R.raciborskii和其他适应低磷条件的蓝细菌的繁殖。