Marschall Mariann, Proctor Michael C F
Department of Plant Physiology, Eszterházy Károly College, H-3301 Eger, Leányka út 6-8, Hungary.
Ann Bot. 2004 Oct;94(4):593-603. doi: 10.1093/aob/mch178. Epub 2004 Aug 19.
Data are presented from 39 species of mosses and 16 liverworts for ratios of chlorophylls and total carotenoids, and light saturation of photosynthetic electron flow or photosynthetic CO2 uptake, in relation to the postulate that bryophyte cells in general show shade-plant characteristics.
Pigment concentrations were measured by spectrophotometer in 80 % acetone extracts. Light-saturation curves were constructed by (modulated) chlorophyll florescence and for some species by infra-red gas analysis.
The pigment measurements were widely variable but broadly in line with the findings of previous authors. Median values (mosses/liverworts) were: total chlorophyll, 1.64/3.76 mg g(-1); chlorophyll a : b, 2.29/1.99; chlorophylls : carotenoids, 4.74/6.75). The PPFD values at 95 % saturation (estimated from fitted curves) also ranged widely, but were almost all <1000 micromol m(-2) s(-1); the median for mosses was 583 and for liverworts 214 micromol m(-2) s(-1). The two highest PPFD95% values were from Polytrichum species with lamella systems forming a ventilated photosynthetic tissue. Total chlorophyll, chlorophyll a : b and chlorophylls : carotenoids all correlated significantly with PPFD95%.
Bryophytes include but are not inherently shade plants. Light-saturation levels for species of open sun-exposed habitats are lower than for vascular sun plants and are probably limited by CO2 diffusion into unistratose leaves; this limit can only be exceeded by bryophytes with ventilated photosynthetic tissues which provide increased area for CO2 uptake.
针对39种苔藓植物和16种地钱，给出了叶绿素与总类胡萝卜素的比率，以及光合电子流或光合二氧化碳吸收的光饱和情况的数据，这与苔藓植物细胞通常表现出阴生植物特征的假设相关。
通过分光光度计测量80%丙酮提取物中的色素浓度。通过（调制）叶绿素荧光构建光饱和曲线，部分物种则通过红外气体分析构建。
色素测量结果差异很大，但大致与先前作者的研究结果一致。中位数（苔藓植物/地钱）为：总叶绿素，1.64/3.76毫克/克；叶绿素a:b，2.29/1.99；叶绿素:类胡萝卜素，4.74/6.75）。95%饱和时的光合有效辐射（PPFD）值（根据拟合曲线估算）范围也很广，但几乎都<1000微摩尔·米-²·秒-¹；苔藓植物的中位数为583，地钱为214微摩尔·米-²·秒-¹。两个最高的PPFD95%值来自具有形成通风光合组织的片状系统的金发藓属物种。总叶绿素、叶绿素a:b和叶绿素:类胡萝卜素均与PPFD95%显著相关。
苔藓植物包括但并非天生就是阴生植物。暴露于开阔阳光下生境的物种的光饱和水平低于维管束阳生植物，可能受到二氧化碳扩散到单层叶中的限制；只有具有通风光合组织、能提供更多二氧化碳吸收面积的苔藓植物才能超过这一限制。
