Seasonal patterns in the photosynthetic capacity, tissue pigment and nutrient content of different developmental stages of Undaria pinnatifida (Phaeophyta: Laminariales) in Port Phillip Bay south-eastern Australia
Seasonal patterns in the photosynthetic capacity, tissue pigment and nutrient content of different developmental stages of Undaria pinnatifida (Phaeophyta: Laminariales) in Port Phillip Bay south-eastern Australia
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DOI：
10.1515/bot.1999.027
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发表时间：
1999-05-01
期刊：
影响因子：
2.2
通讯作者：
Burridge, TR
中科院分区：
文献类型：
--
作者：
Campbell, SJ;Bité, JS;Burridge, TR
光合性能，暗呼吸，色素浓度，组织营养浓度和鲜：干重比测定在整个生长季节的菲利普港湾裙带菜孢子体的少年和成年。裙带菜孢子体各阶段的光合速率（15 ~ 42 mg O-2 g（-1）dw h（-1））春季高于夏季，与春季幼孢子体的快速生长相一致。成年裙带菜孢子体的dw：fw比年轻的孢子体。在P-max和阿尔法叶绿素a的基础上在幼年植物的季节性趋势解释较高的色素（叶绿素a，c，岩藻黄素）浓度在春季比夏季。孢子体生活阶段之间的色素含量和它们的比例的差异可能是幼年植物光适应的指示。较低的饱和光需求（Ik）和补偿点（I，）在春季观察到的夏季植物和较低的Ik值的幼年孢子体相比，成年孢子体也被发现在春季。春、夏季的补偿点大多在7.63 ~ 15.49 μ mol m（-2）s（-1）之间。低I-K和I-C，和高P-max，α，和色素含量可能会提高青少年裙带菜利用低光子通量率的能力。无季节差异，发现呼吸速率之间的干重的基础上，或在年轻和成年孢子体之间的呼吸。在夏季，幼鱼和成年鱼的呼吸速率按叶绿素a标准化，高出2-3倍。高C：N比（原子）在少年（春季平均值= 20.2，夏季平均值= 27.9）和成年孢子体（春季平均值= 11.32，夏季平均值= 18.6）表明较高的积累储备碳水化合物的少年植物和氮限制在夏季。从冬季到夏季，两个阶段的组织C：N比增加。春季和夏季两个阶段的低N：P比（< 5）也暗示了N限制。总体而言，高N的可用性在港口菲利普湾和低光适应的生理特性提供裙带菜与其他快速增长的大型藻类的竞争优势。
Photosynthetic performance, dark respiration, pigment concentration, tissue nutrient concentration and fresh:dry weight ratios were measured in juvenile and adult sporophytes of Undaria pinnatifida throughout the growing season from Port Phillip Bay. The photosynthetic rates (15 to 42 mg O-2 g(-1) dw h(-1)) of Undaria pinnatifida sporophyte stages were higher on a dry weight basis in spring compared to summer coinciding with rapid growth of juvenile sporophytes in spring. Higher dw:fw ratios of adult Undaria sporophytes were found compared to young sporophytes. The seasonal trends in P-max and alpha on a Chl a basis in juvenile plants are explained by higher pigment (Chl a, c, fucoxanthin) concentrations in spring than summer. Differences in pigment content and their ratios between sporophyte life stages may be indicative of light adaptation by juvenile plants. Lower saturated light requirement (Ik) and compensation points (I,) were observed in spring compared to summer plants and lower Ik values of juvenile sporophytes compared to adult sporophytes was also found during spring. Spring and summer compensation points in this study mostly ranged from 7.63 to 15.49 mu mol m(-2) s(-1). Low I-k and I-c, and high P-max, alpha, and pigment content may enhance the capacity of juvenile Undaria to utilise low photon flux rates. No seasonal differences were found between respiration rates on a dry weight basis or between respiration in young and adult sporophytes. Respiration rates normalised to Chl a, were 2-3 times higher in summer in both young and adult stages. High C:N ratios (by atom) in juvenile (spring mean = 20.2; summer mean = 27.9) and adult sporophytes (spring mean = 11.32; summer mean = 18.6) indicate a higher accumulation of reserve carbohydrates by juvenile plants and N limitation in summer. Tissue C:N ratios increased in both stages from winter through to summer. Low N:P ratios in spring and summer for both stages (< 5) is also suggestive of N limitation. Overall the high N availability in Port Phillip Bay and the low light adapted physiological characteristics provide Undaria with a competitive advantage over other fast growing macroalgae.