STEADY-STATE LUXURY CONSUMPTION AND THE CONCEPT OF OPTIMUM NUTRIENT RATIOS - A STUDY WITH PHOSPHATE AND NITRATE LIMITED SELENASTRUM-MINUTUM (CHLOROPHYTA)
STEADY-STATE LUXURY CONSUMPTION AND THE CONCEPT OF OPTIMUM NUTRIENT RATIOS - A STUDY WITH PHOSPHATE AND NITRATE LIMITED SELENASTRUM-MINUTUM (CHLOROPHYTA)
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DOI：
10.1111/j.0022-3646.1985.00592.x
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发表时间：
1985-12-01
影响因子：
2.9
通讯作者：
TURPIN, DH
中科院分区：
文献类型：
--
作者：
ELRIFI, IR;TURPIN, DH
微量硒（英文）在磷酸盐或硝酸盐限制下，在大量过量添加非限制性营养的情况下，柯林斯的生长速度范围很广。这导致奢侈品消费饱和。生长速率与细胞配额之间的关系可以用下垂关系来描述。kQ.cntdot. qmax -1所反映的N细胞配额在N限制下的变异性与以前报道的值相似，但P在P限制下的kQ.cntdot. qmax -1比以前报道的其他物种更大。根据最佳比率假设对这些结果进行了评价。我们的研究结果支持了先前的工作，表明使用单一最佳比例(kQ .cntdot。kQj-1)不适合处理在稳态营养限制下生长的物种。在这些条件下，最佳比例应被视为增长率的因变量。提出了两种检验最佳比率增长率相关性的方法。不同营养物质的奢侈品消费能力不同，并且依赖于生长速率。在低生长速率下，P的奢侈消费系数（Rsat）约为N的4倍。在这些条件下，N和P细胞配额之间的所有可能关系的集合被报道，然后这些值被用来建立细胞N:P生态位边界。非限制性营养物质的细胞配额不能用下垂方程来描述。分析表明，当细胞N:P比值偏离最佳比值时，drop方程描述生长速率与非限制性细胞配额关系的能力下降。当非限制性营养细胞配额饱和时，下垂方程似乎无效。总结了以前报道的非限制性营养利用模式，以支持这一结论。考虑了奢侈品消费和增长率依赖的最佳比率的生理和生态后果。
Selenastrum minutum (Naeg.) Collins was grown over a wide range of growth rates under phosphate or nitrate limitation with non-limiting nutrients added to great excess. This resulted in saturated luxury consumption. The relationships between growth rate and cell quota for the limiting nutrients were well described by the Droop relationship. The observed variability in N cell quota under N limitation as reflected in kQ.cntdot.Qmax-1, was similar in magnitude to previously reported values but kQ .cntdot.Qmax-1 for P under P limitation was greater than previously reported for other species. These results were evaluated in light of the optimum ratio hypothesis. Our findings support previous work suggesting that the use of a single optimum ratio (kQ .cntdot. kQj-1) is inappropriate for dealing with a species growing under steady-state nutrient limitation. Under these conditions the optimum ratio should be viewed as a growth rate dependent variable. Two approaches for testing the growth rate dependency of optimum ratios are proposed. The capacity for luxury consumption differed between nutrients and was growth rate dependent. At low growth rates, the coefficient of luxury consumption (Rsat) for P was ca. four times that for N. The set of all possible relationships between N and P cell quota under these conditions was reported and these values were then used to establish the cellular N:P niche boundaries for S. minutum. Cell quotas of non-limiting nutrients were not described by the Droop equation. Analysis showed that as the cellular N:P ratio deviates from the optimum ratio, the ability of the Droop equation to describe the relationship between growth rate and non-limiting cell quotas decreases. When non-limiting nutrient cell quotas are saturated, the Droop equation appears to be invalid. Previously reported patterns of non-limiting nutrient utilization are summarized in support of this conclusion. The physiological and ecological consequences of luxury consumption and growth rate dependent optimum ratios are considered.