Effects of ultraviolet radiation on different life cycle stages of the south Pacific kelps, Lessonia nigrescens and Lessonia trabeculata (Laminariales, Phaeophyceae)
Effects of ultraviolet radiation on different life cycle stages of the south Pacific kelps, Lessonia nigrescens and Lessonia trabeculata (Laminariales, Phaeophyceae)
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紫外线辐射对南太平洋海带、Lessonia nigrescens 和Lessonia trabeculata（海带目、褐藻纲）不同生命周期阶段的影响
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
I. Gómez
中科院分区：
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作者：
K. Véliz;M. Edding;F. Tala;I. Gómez
研究了280 - 400 nm紫外线对海带Lessonia nigrescens和L. trabeculata，收集在东南太平洋沿岸（30 ° S）进行了评价。萌发和活力（游动孢子，定居孢子），配子体的初级细胞的直径，雌配子体的百分比，生育力和孢子体生产后，暴露于三种辐射处理（PAR，PAR + UVA，PAR + UVA + UVB）进行了测量。以光系统II（PSII）叶绿素荧光最大量子产率（Fv/Fm）的变化来评价UVR对幼孢子体（二倍体阶段）的影响。与对照组相比，在暴露2和4小时后，观察到包括UVB（PAR + UVA + UVB）的治疗组的所有变量均显著降低。活动孢子对紫外线辐射的敏感性高于定居孢子和配子体，这表明沿着个体发育的增加，对紫外线辐射的耐受性也增加。此外，还观察到潮间带L.与潮下带L.小梁这些结果可以初步推断，紫外线辐射可能被视为一个重要的环境因素，影响这些物种的分布上限，主要是通过其对生命周期的早期阶段的有害影响。
The effects of exposure to ultraviolet radiation (UVR), 280–400 nm, in different life histories and development stages of the kelps, Lessonia nigrescens and L. trabeculata, collected in the south-east Pacific coast (30°S) were evaluated in the laboratory. Germination and viability (motile zoospores, settled spores), diameter of the primary cell of the gametophytes, percentage of female gametophytes, fertility and sporophytes production were measured after exposure to three radiation treatments (PAR; PAR + UVA; PAR + UVA + UVB). The effects of UVR in young sporophytes (diploid stage) were evaluated as changes in maximal quantum yield of chlorophyll fluorescence of photosystem II (PSII) (Fv/Fm). A significant decrease in all variables was observed for the treatment that included UVB (PAR + UVA + UVB) after 2 and 4 h of exposure, in relation to the control. The motile spores were more sensitive to UVR exposure compared to settled spores and gametophytes, suggesting that along with an increase in ontogenetic development; there is an increase in the tolerance to UVR. In addition, it was observed that early stages of the intertidal L. nigrescens were more tolerant to UVR compared to the subtidal L. trabeculata. These results allow initially to infer that UVR may be regarded as an important environmental factor influencing the upper limit of distribution of these species, mainly through its detrimental effects on the early stages of the life cycle.