کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6383670 | 1626339 | 2014 | 30 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Does the 14C method estimate net photosynthesis? II. Implications from cyclostat studies of marine phytoplankton
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
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![عکس صفحه اول مقاله: Does the 14C method estimate net photosynthesis? II. Implications from cyclostat studies of marine phytoplankton Does the 14C method estimate net photosynthesis? II. Implications from cyclostat studies of marine phytoplankton](/preview/png/6383670.png)
چکیده انگلیسی
Two species of marine phytoplankton, Isochrysis galbana and Chlorella kessleri, were grown in a continuous culture system on a 12-h:12-h light:dark cycle of illumination under nitrate-limited growth conditions. At growth rates of ~1Â dâ1, production rates estimated from 14C uptake were not significantly different from production rates estimated from changes in particulate organic carbon (POC) and total organic carbon (TOC). At growth rates of ~0.35Â dâ1, however, production rates based on uptake of 14C significantly (p<0.05) overestimated production rates based on changes in POC and TOC in all cases for C. kessleri and after 24Â h for I. galbana. The ratio of production based on 14C uptake to production based on changes in POC and TOC concentrations was in all cases higher after 24Â h than after 12Â h. The extent of overestimation after a 24-h incubation at ~0.35Â dâ1 was about 23 and 40% in the cases of I. galbana and C. kessleri, respectively. Dark respiration rates estimated from changes in 14C activity during the dark period were lower than the rates estimated from changes of POC and TOC concentrations during the 12Â h of darkness because only about 73% of the carbon respired during the dark period had been fixed during the previous 12-h photoperiod. The fact that the 14C method tends to overestimate net carbon assimilation by a greater percentage at low growth rates than at high growth rates probably reflects the greater efficiency of intracellular recycling of respired CO2 at high growth rates. The fact that the extent of overestimation is greater when cells are grown on a light:dark cycle probably reflects the fact that not all carbon respired in the dark was fixed during the previous photoperiod and that intracellular recycling of respired CO2 during the photoperiod is inefficient during some phases of the synchronized growth that tends to be entrained by light:dark cycles.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Deep Sea Research Part I: Oceanographic Research Papers - Volume 91, September 2014, Pages 94-100
Journal: Deep Sea Research Part I: Oceanographic Research Papers - Volume 91, September 2014, Pages 94-100
نویسندگان
Shaofeng Pei, Edward A. Laws,