三十烷醇对海带三个品系雌配子体克隆生长和发育的影响

以海带雌配子休克隆为实验材料,通过施用三十烷醇处理。结果表明,三个品系在供试条件下,LH36生长最好,LH30发育率最高。它们对TA的反应为浓度在0．5～1．0×10-5mg／L时,都有促生长作用,其中LH30反应最敏感,LH10次之。浓度在1．0×10-5mg／L时,发育率最高,其中LH30发育率为51．5％,LH10为18．0％。LH36对各浓度处理的发育反应,差异都不明显。     

三十烷醇对海带叶绿体超微结构的效应

本文将经不同浓度三十烷醇处理的海带进行电镜切片观察,结果表明经三十烷醇处理后的海带,其叶绿体形态发生显著改变。与对照组相比,叶绿体中的类囊体片层增多,基质浓厚,其外形更为饱满,光合作用的强弱与类囊体片层的多少关系密切。文中从细胞学的水平上分析了三十烷醇促进海带增产的内在原因。     

三十烷醇乳粉在海带养殖上的应用试验

本文报道了三十烷醇乳粉在北方海带养殖中的应用。在海带苗出库时，用浓度为０．５ｐｐｍ的三十烷醇乳粉将其浸泡１２小时，或夹苗时用浓度假ｐｐｍ，将其浸泡２小时，可使海带增产２０％左右。此法低耗高效，简单易行，适宜于海带养殖中大面积推广。     

三十烷醇对几种单细胞藻生长影响的研究

于1988－1990年，在大连凌水养殖二场，用0．01×10－6－1．00×10－6三十烷醇处理亚心形良藻、盐藻、微球藻、球等鞭金藻、新月菱形康，观察其对漠的生长影响。结果表明，在各种浓度下以上5种藻均提早进人指数生长期。对前3种藻的最佳处理浓度为0．10×10－6；后2种藻为0．05×10－6；其中对亚心形扁藻，促生长效果尤为明显，可视为海产经济动物人工育苗阶段的优质饵料。     

三十烷醇对极大螺旋藻生物量及生化组成的影响

在Zarrouk液体培养基中加入1g/m3液体三十烷醇(LTA),极大螺旋藻(Spirulina maxima)的生物量增加了24.6%~25.7%,即使在碳源NaHCO₃减半(实验组2)的条件下生物量仍增加了4.43%~4.92%;碳水化合物含量增加了11.9%~16.0%,在实验组2条件下也增加5.7%~8.3%;叶绿素增加率为45.8%~63.3%;蛋白质总量基本不变,但水溶性蛋白的含量明显增加,从对照组的36%增长至实验组的60%左右,而水不溶性蛋白的含量则明显从30%左右减至10%左右.从螺旋藻生产基地的中试培养结果看,加入1g/m3液体三十烷醇,生物量提高了39.76%,比在实验室条件下获得更好的增产效果,但加入固体三十烷醇(STA)反而减少12%.以上结果表明,在极大螺旋藻培养基中添加液体三十烷醇可大幅度提高生物量和生化组成的含量.     

三十烷醇对海带产量及成分的影响

三十烷醇不仅能迅速诱导许多植物的生长反应,对其生理活性及产量也有明显的影响。它能促进光合,提高玉米、水稻幼苗活体或离体中氨基酸和可溶性蛋白质及总氮水平,对于与高等植物细胞成分、生理特征不尽相同的大型海藻也有明显的生理活性。在系统测定三十烷醇对海带生长和生理活性影响的基础上,我们又进一步探讨了三十烷醇对海带产量及成分的影响,以期为提高产量及其经济价值提供理论依据。     

硼对海带雌配子体生长的影响

硼对高等植物生长的影响，已有不少的研究．有人认为它是植物生长所必需的元素，有人不同意这个意见。硼对海藻的效应，研究的不多．McBride等的观察指出，硼对小球藻的生长没有什么影响。Lewin的实验表明，硼对硅藻的生长是必需的．Nasr等的观察指出，     

沿岸流与海带养殖关系的研究：Ⅱ、流速对海带生长的影响

本研究的第一部分，报告了山东省日照县石臼所湾海带养殖区的沿岸流的研究结果，提出了该海区海带养殖筏合理设置的措施。经过二年的生产证明，合理设筏(依主流轴向顺流设筏)后，改善了养殖区的流水条件，促进了海带的生长，减轻了风浪灾害，使该海区海带的产量得到提高。1980—1981年我们又在山东省荣成县俚岛湾，进行了不同流速条件下的海带生长与产量的定量试验，本文即报告此项研究的结果。     

养殖海带的生长模型研究

国内外关于海带生长和光合作用与其生长环境因素的关系研究开展的较多,但缺乏有效的模型来预测评估环境条件变化对海带生长和产量的影响.因此,根据海带生理生态学实验数据、现场观测的光照强度、温度和营养盐等影响海带生长与光合作用的环境参数和海带生长测定数据,运用动态模拟手段,建立了一个数学模型,并利用视窗化模型软件Stella9.0TM构建和运行了上述模型,用来模拟和预测海带(Laminaria japonica)的生长过程.同时,对模拟值和实测值进行了相关性分析及其检验,结果表明,该模型较好地模拟了生长海带的长度和干重,可以为相关研究和管理提供服务.     

UV-B辐射对海带幼孢子体生长和生理的影响

探讨UV-B辐射对海带幼孢子体的影响,运用实验生态学的方法,研究了高(93.6 J·m-2·d-1)、中(46.8 J·m-2·d-1 )、低(11.7 J·m-2·d-1)3个剂量的UV-B辐射对海带幼孢子体生长和生理状况的影响.辐射处理期间(第2～10天),3个辐射剂量处理组的海带幼孢子体体长和体重的相对增长率显著低于对照组(0 J·m-2·d-1);第6～10天期间,低剂量处理组和高剂量处理组的叶绿素a(Chl-a)含量与对照组相比呈现出完全相反的变化趋势,前者显著高于对照组,后者显著低于对照组;中、高剂量处理组的ATP酶活性在整个实验期间均显著低于对照组,而低剂量组与对照组无显著差异.氮(N)、磷(P)元素缺乏与中剂量UV-B联合作用条件下的海带幼孢子体体长、体重相对增长率与中剂量单独处理组无显著差异;辐射处理初期(第2～4天),N、P缺乏与中剂量UV-B辐射共同处理组的ATP酶活性明显高于单独辐射处理组,后期(第10天)则显著低于单独辐射处理组;N、P元素缺乏加剧了中剂量UV-B辐射对海带幼孢子体Chl-a含量的影响效应,N、P缺乏与中剂量UV-B辐射共同处理组的Chl-a含量显著低于中剂量UV-B辐射处理组.在高剂量UV-B辐射处理的同时,附加一定强度的光合有效辐射(photosynthetically active radiation,PAR,400～700 nm)能在一定程度上减轻UV-B辐射对海带幼孢子体生长和生理状况的影响程度.     

The effects of copper on the fine structure of the kelp Laminaria saccharina (L.) Lamour

The effects of copper on the fine structure of Laminaria saccharina were examined by incubating plants in 50, 100 and 500 μg Cu per liter of filtered and uv-treated seawater media.Copper treatment after fertilization in gametophytes yielded sporophytes that showed abnormal growth patterns, haptera-like protuburances, giant cells and abnormal branching patterns in 50 μg liter^-1 and 100 μg liter^-1copper additions.Ultrastructural examination of the plants which showed abnormality and chlorosis indicated the presence of denatured chloroplasts with swollen thylakoid membranes, detachment of thylakoid lamellae and diffused matrices.     

Secondary production in a Laminaria hyperborea kelp forest and variation according to wave exposure

The secondary production of mobile invertebrate fauna in the Laminaria hyperborea (Gunn.) Foslie kelp forest increases with wave exposure level. This faunal group has a key function in transferring kelp carbon to higher levels in the food web. By using a size-frequency method the calculated production was 68 (±18) g D.W. m⁻² yr⁻¹ (±S.E.) at low, 250 (±57) at medium and 308 (±64) at high exposure levels. The calculations included 30 macrofauna species, which accounted for 96% of the specimens registered, with Gastropods, amphipods and bivalves being the most abundant taxa. The calculated secondary production is high, but comparable to that previously reported from other macrophyte systems and was 3%, 8% and 8% of the total primary production at low, medium and high exposure levels, respectively. Our results indicate that large quantities of Laminaria kelp are exported from the system, although the production of sessile animals was not taken into account. The most important factor in determining faunal densities and secondary production was probably habitat size but at low exposure levels the percentage of egg-carrying crustacean females and juveniles were lower than at medium and high exposure levels, thereby indicating lower fitness for animals at low exposure stations.     

Effects of Dredging Activities on Growth of Laminaria saccharina

Abstract. The possible effects of fine-grained deposits on the photosynthesis, growth, and nutrient uptake of Laminaria have been studied in field and laboratory experiments. Some of the plants were treated with fine-grained material for two hours and then transplanted in rows together with untreated plants. At two-week intervals the treatment was repeated and samples collected. The macroalgae were analyzed for growth as well as chlorophyll a , nitrogen, and phosphorus content. In the laboratory experiments, plants of a uniform size were incubated in Plexiglas containers after leaf-marking and treatment in a sediment suspension. At weekly intervals, photosynthesis, growth, chlorophyll a , and nutrients were analyzed.
The field study showed that Laminaria growth was significantly affected by the fine-grained material. The growth in the control experiment was 20% higher than in the treated plants. The chlorophyll a concentrations in the treated plants were significantly lower than in the control experiment, and the results indicated a reduced nutrient uptake in the treated plants. In the laboratory experiments the growth of the treated plants was only 30% of the controls, but no differences in photosynthetic capacities were detected. Nitrogen uptake was reduced in the treated plants, but no effects were observed on phosphorus uptake. Thick layers of fine-grained material caused direct harmful effects and rotting.
The results are discussed in relation to dredging activities; it is concluded that in heavy sedimentation areas, Laminaria growth may be significantly reduced beyond the indirect effect of shading from suspended material in the water.     

Food web structure within kelp holdfasts (Laminaria): a stable isotope study

Kelp holdfasts are highly reticulated structures which host a large diversity of small fauna. These microhabitats have been reported to play a crucial role in the biodiversity associated to kelp forest ecosystems. This study aimed at identifying trophic links and the main food sources sustaining food webs within communities associated with kelp holdfasts, through a stable isotope (δ¹³C and δ¹⁵N) approach. Sampling of the main invertebrates inhabiting Laminaria digitata holdfasts, and of their potential food sources, took place in February and May 2007. Stable isotope results reveal that most of the primary consumers, including filter-feeders and deposit-feeders, rely on the particulate organic matter sedimented within kelp holdfasts. Only three grazers departed from this general pattern. The correspondence between the stable isotope ratios of predators and sediment consumers indicated that this source is at the base of the main pathway through which energy and matter transit in the food web. δ¹⁵N ranges found for consumers revealed that the food web associated with kelp holdfasts is composed of 3.5 levels. In spite of the low diversity of food sources at the base of the food web, these microhabitats can therefore be considered micro-scale ecosystems, from a functional perspective.     

Physiology of Laminaria

Abstract. Discs of lamina tissue excised from Laminaria digitata, L. hyperborea and L. saccharina were unaffected by cutting. They photosynthesized at a constant rate for several days and increased in area and weight during prolonged bubble cultures at a rate comparable with that of plants on the shore.     

Physiology of Laminaria

Abstract. Dissolved nitrate, nitrite, ammonium and phosphate were monitored for 2.5 years along a coastal eutrophication gradient originating at the St. Andrews sewer outfall. Linear growth rates and tissue composition (phosphorus, various nitrogen fractions and storage carbohydrates) were monitored at the same stations in lamina tissue of Laminaria digitata and L. saccharina. Growth rates were considerably enhanced at the eutrophicated stations both in spring, when exogenous nutrients were at peak values at all stations, and during the summer when exogenous nutrients were very low at all stations. Enhanced summer growth rates were correlated with the increased reserves of N and P accumulated during winter and spring, and particularly with soluble organic nitrogen reserves. Accumulation of storage carbohydrates was inversely correlated with growth rate and tissue N and P reserves, presumably because fixed carbon could be incorporated into new protein and thence new tissue only if internal non-protein N reserves were available.     

Physiology of Laminaria

Abstract. Sporophytes of Laminaria digitata and L. saccharina were collected from the shore at different times of year. Intact sporophytes of both species, and discs cut from L. digitata lamina tissue were maintained for several weeks in laboratory cultures under various nitrate, phosphate, temperature and daylength regimes. Substrate-saturated uptake rates of approximately 24 μgN g dry weight^-1 h^-1 from 20 μM nitrate and 8 μgP g dry weight^-1 h^-1 from 10 μM phosphate were more than sufficient to account for internal nitrogen and phosphorus accumulation. Other nitrogen sources - nitrite, ammonium and urea - were also taken up, independently of each other, and supported growth. During the late spring decline of ambient nutrient levels, when growth rates on the shore also decline markedly, enrichment with nitrate (15 μM) and phosphate (3μ) together prevented this decline and also maintained peak photosynthetic rates (net photosynthesis = 10.4 μlO₂ cm^-2 h^-1) which otherwise dropped to 4.5 μO₂ cm^-2 h^-1 over 47 days at ambient nutrient levels (0.5 μM nitrate and phosphate). Slow summer growth rates in June/July were enhanced to greater than spring peak values by combined nitrate (7.5 μM) and phosphate (1.8 μM) enrichment; neither was sufficient alone, although the individual nutrients were accumulated internally. A lesser, but significant enhancement was also achieved in September. In midwinter, nutrient enhancement itself (10.5 μM nitrate and 3.0 μM phosphate) had a small effect on growth rates only if summer water temperature (15°C) was used, but the dramatic effect of an increased photoperiod (7.5 to 17.5 h) was in excess of that expected for the increased radiant energy available. This was found to be due, at least in L. digitaia discs, to the re-establishment of a surface meristoderm in the dormant winter tissue; this was particularly active with high phosphate supply. Growth of the new lamina in January on the shore was much reduced if the old lamina was removed, although the time of initiation of new growth remained unchanged. In the laboratory, the old lamina was found to be a source of nitrogen for new lamina but not of fixed carbon or phosphorus. New lamina photosynthesis, manifest as mannitol accumulation, was directly proportional to phosphate supply up to at least 7.5 μM phosphate. Mannitol accumulation was then suppressed by a nitrate supply above 12 um, presumably by diversion of fixed carbon to other biosynthetic pathways.     

Trophic significance of the kelp Laminaria digitata (Lamour.) for the associated food web: a between-sites comparison

This study aimed at establishing the trophic significance of the kelp Laminaria digitata for consumers inhabiting two rocky shores of Northern Brittany (France), displaying contrasted ecological conditions. The general trophic structure did not vary between these two sites, with a wide diversity of filter-feeders and predators, and only 14% of the species sampled belonging to the grazers' trophic group. The diversity of food sources fueling the food web appeared also similar. The food webs comprised four trophic levels and the prevalence of omnivory appeared relatively low compared to previous studies in the same area. Conversely, to the food web structure, which did not differ, the biochemical composition of L. digitata differed between the two sites, and was correlated to a larger diversity of grazers feeding on this kelp in sheltered conditions. This indicated that the spatial variability occurring in the nutritive value of L. digitata is likely to deeply affect the functioning of kelp-associated food webs. The contribution of L. digitata-derived organic matter to the diet of filter-feeders inhabiting these two environments was assessed using the mixing model Isosource, which showed the higher contribution of kelp matter in sheltered conditions. These results highlight the spatial variability that may occur in the functioning of kelp-associated food webs. Moreover, this suggests that hydrodynamics is likely to control the availability of kelp-derived organic matter to local filter-feeders, probably through an increase of detritus export in exposed areas.     

日本真海带对硒的积累和生物转化

在海水中添加亚硒酸盐(Na₂SeO₃)及不同浓度的氮磷营养盐(NaNO₃+NaHO₂PO₄),研究海带对硒的积累,通过分离测定海带富硒前后各生化组分的含硒量来探讨硒的生物转化问题.结果表明天然海带含硒量(鲜重)为0.451~0.596μg/g,海带富硒最佳的Na2SeO₃浓度为200mg/dm3,培养56h后的富硒倍率约为50.在天然海带中,硒主要以有机态存在,有机硒占总硒含量的86.22%;在含有200mg/dm3NaO₂SeO₃的海水中培养56h后测得海带的总硒为24.481μg/g,其中有机硒含量为16.703μg/g,无机硒为4.714μg/g;在添加氮磷营养盐的含硒海水中,海带的富硒能力得到进一步的提高,在适宜的氮磷条件下(150mg/dm3NaNO₃和25mg/dm3NaHO₂PO₄)总硒含量达到33.649μg/g,而无机硒含量基本不变,为4.497μg/g,因此提高部分转化为有机硒,有机硒含量达到24.678μg/g.这说明海带具有通过自身代谢将无机硒转化为有机硒的较强的能力.