Pigment characterisation of suspended matter in association with particulate heavy metal loadings in the German Bight and Elbe Estuary

The pigment fingerprints, determined by HPLC, of suspended matter from different areas of the German Bight and from the Elbe Estuary are presented. These include areas with suspended matter concentrations varying between 10 mg l^–1 in the deeper waters in the middle of the Bight and 150 mg l^–1 in the Elbe mouth. Pigment data allows the identification of three groups of suspended matter (marine, turbidity zone and Elbe) for the numerous different locations. The changes in pigment concentrations in the suspended matter over tidal cycles are considered. The presence of pigments and pigment breakdown productsi.e. lutein and chlorophyllides is used to assess the possible condition of the phytoplankton present in the suspended matter. These pigment characteristics are compared with the loading of the heavy metals cadmium, copper, manganese, iron, zinc and lead in the particulate matter. It has been demonstrated that the pigments of the planktonic material can be used very effectively to identify different types of suspended matter and that the heavy metal loadings of the suspended matter were significantly correlated with chlorophyll-a.     

SEPARATION OF CHLOROPHYLLS c1c2, AND c3 OF MARINE PHYTOPLANKTON BY REVERSED-PHASE-C18-HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY1

We separated chlorophylls c₁ c₂, and c₃ of marine phytoplankton together with other pigments by a modification of the commonly applied reversed-phase-C18-high-performance liquid chromatography (RP-C18-HPLC) method. However, the chlorophyll c-like pigment 2,4, Mg-divinylpheoporphyrin as monomethyl ester, co-eluted with chlorophyll c₁. The method involves optimization of the mobile phase by using a very high ion strength solvent in combination with a high carbon loaded RP-C18 column. Fingerprints of the various taxonomic groups of algae can thus be developed in a single run, including separation of the carotenoids lutein and zeaxanthin.     

Antennal sensilla of the ground beetle Bembidion lampros Hbst (Coleoptera, Carabidae)

Antennal sensilla typology, number and distribution pattern were studied in the ground beetle Bembidion lampros Hbst (Coleoptera, Carabidae) using scanning electron microscopy. The 1.6–1.8 mm long filiform antennae of both sexes consist of the scape, pedicel and of the flagellum composed of nine flagellomeres. In both sexes, three types of sensilla chaetica, two types of sensilla trichodea, five types of sensilla basiconica, one type of sensilla coeloconica, one type of sensilla campaniformia and Böhm sensilla were distinguished. The possible function of the sensilla was discussed and three types of sensilla were considered as olfactory, sensilla trichodea type 2 and sensilla basiconica types 1 and 2. Olfactory sensilla occupy dorsal and/or ventral areas of the flagellomeres and occur sparsely (sensilla basiconica type 1) or not at all (sensilla basiconica type 2 and sensilla trichodea type 2) outside these areas. No remarkable sexual differences in the types, numbers and distribution of antennal sensilla were found.     

Histochemical and biochemical approaches to the study of phenolic compounds and peroxidases in needles of Norway spruce (Picea abies)

The three youngest age-classes of needles of Norway spruce ( Picea abies ) were collected from four sites in the Krusne Hory Mountains (Czech Republic) characterized by different levels of damage caused by environmental pollution. Histochemical methods did not reveal any differences in localization of phenolics among the needles. Mesophyll cells close to the epidermis of needles and cells around resin ducts and substomatal cavities often accumulated higher amounts of phenolics than the rest of the mesophyll cells, but this was independent of age and damage. Needles of different age- and damage-class did not show any marked changes in general lignification pattern. However, a lower intensity of histochemical detection of lignin was observed in needles from the most damaged site. This finding was confirmed by chemical analysis using thioglycolic acid. Generally, the amount of lignin in mesophyll cells was lower in damaged trees than in healthy ones. Using the Folin–Ciocalteau method, no significant differences in the total content of phenolics were observed in the needles, although HPLC revealed marked alterations in the forms of seven phenolic acids. Concentrations of conjugated forms of phenolic acids (esters and glycosides) were higher in damaged needles (255.9 μg g⁻¹ f. wt) than in healthy needles (189.8 μg g⁻¹ f. wt). By contrast, content of esterified phenolic acids incorporated into cell walls was higher in needles from healthy trees (101.1 μg g⁻¹ f. wt) than in damaged needles (78.3 μg g⁻¹ f. wt). Marked differences were also observed in the activity of soluble peroxidases, although the activity of ionically bound forms was approximately the same in healthy and damaged needles. The total amounts of chlorophylls and carotenoids decreased as environmental damage increased.     

荔枝蝽触角化感器的扫描电镜观察

应用扫描电镜技术研究了荔枝蝽(Tessaratoma papillosaD rury)触角化感器的类型、数量和分布。结果表明,毛形感器、刺形感器和锥形感器在荔枝蝽雌雄虫触角上均有分布,其中以毛形感器最多,且毛形感器数量和分布在雌雄间有明显的不同。另外,雄虫触角上还分布有念珠形感器,而腔形感器在雌虫触角上有分布,这2种感器数量相对较少。     

Salt Tolerance in Aquatic Macrophytes: Ionic Relation and Interaction

Effects of seawater salinity (SWS) and pure NaCl on the intracellular contents of Na⁺, K⁺, Mg²⁺, Ca²⁺, chlorophylls (Chl) and carotenoids (Car) were studied in three submerged aquatic macrophytes, Hydrilla verticillata, Najas indica and Najas gramenia, which differed in their tolerance to salinity. NaCl resulted in significant increase in Chl/Car ratio in the salt-sensitive H. verticillata and moderately salt-tolerant N. indica, but not in the salt-tolerant N. gramenia. SWS treatment did not result in any significant change in the ratio. The intracellular content of Na⁺ increased significantly in all the test plants upon exposure to both NaCl and SWS. The content of K⁺ decreased significantly in these plants upon salinity treatment, except in N. gramenia. The contents of Ca²⁺ and Mg²⁺ decreased significantly upon NaCl treatment and remained unchanged or increased upon SWS treatment. No relationship between salt tolerance and K⁺/Na⁺ ratio was observed. The maintenance of a minimal level of K⁺ was observed to be the most probable requirement of salt tolerance in aquatic macrophytes.     

Sedimentation of chlorophylls in an Arctic fjord under freshwater discharge

Sedimentation of chlorophylls was studied during summer 1997 in Adventfjorden (Spitsbergen, Arctic). During the period of study, the water column was found to be well stratified by a freshened surface layer (salinity <31 PSS). A high load of suspended particulate matter from riverine discharge reduced the euphotic zone to an interval of 0.4–1.1m. Total particulate matter sedimentation rates were about twice as high in June as in July. The following chlorophylls were distinguished in the sedimented particles: chl a and its degradation products (allomer chl a, phaeophytin a, phaeophorbide a, chlorophyllide a), chl b and chl c ₁+c ₂. The quantitatively most important derivative of chl a was phaeophorbide a (31--41% of porphyrin a). Generally, the sedimentation rate of chlorophylls increased with depth. Linear relationships between concentrations of chl a and phaeophorbide a (r ²=0.92), as well as between concentrations of chl a and phaeophytin a (r ²=0.90) indicated a strong connection between phytoplankton abundance and zooplankton grazing. The significant correlation between chl a and chlorophyllide a concentrations (r ²=0.82) showed that most of the sinking chl a belonged primarily to diatoms, and low chlorophyllide a:chl a ratio (0.03) indicated that cellular senescence was not an important reason for the sinking of chl a. Moreover, very low chl b:chl a ratios (about 0.05 calculated for samples where chl b was detectable) suggest that contributions of green algae and/or higher plant detritus were negligible in sinking particles. The ratio of chl c ₁+c ₂:chl a was 0.85 indicating that chl c-containing algae were dominating.     

Effects of changes in growth temperature on photosynthesis and carotenoid composition in Zea mays leaves

The effects of changes in growth temperature on photosynthesis and carotenoid composition were examined in Zea mays L. leaves of different age and different developmental history. The plants were first grown at sub-optimal temperature (14°C) until the full development of the third leaf. At that time, the mature third leaf and the immature fourth leaf had a low chlorophyll (Chl) content, a low Chl a/b ratio, a high carotenoid/Chl a+b ratio, a high xanthophyll/β-carotene ratio, and about 80% of the xanthophyll cycle pool (violaxanthin [V] + antheraxanthin [A] + zeaxanthin [Z]) was in the form of zeaxanthin and antheraxanthin. When the temperature was increased from 14°C to 24°C for three days, increased Chl synthesis, accompanied by an increase in the Chl a/b ratio, took place. The ratios of lutein, neoxanthin, and V+A+Z to Chl a+b decreased markedly, whereas no significant changes appeared in the β-carotene/Chl a+b ratio. Furthermore, there was a sharp decrease in the xanthophyll/β-carotene ratio and most of zeaxanthin was converted to violaxanthin in the xanthophyll cycle. The third leaf and the tip segment of the fourth leaf, both expanded at 14°C, showed little difference in their pigment contents. However, the rate of CO₂ assimilation of the tip segment of the fourth leaf was nearly twice that of the third leaf on the third day at 24°C, while the photosynthetic activity was similar in both leaves before the transfer to 24°C. During the warm period at 24°C, new leaf tissue (basal segment of the fourth leaf and part of a fifth leaf) was formed. On the third day at 24°C, the pigment content of 24°C-grown leaf tissue did not differ much from that of 14°C-grown leaf tissue with the exception that the total carotenoid content was lower in the former as compared to the latter, mainly because of a lower V+A+Z content. The rate of CO₂ assimilation of 24°C-grown leaf tissue was comparable to that of the tip segment of the fourth leaf. Regardless of which leaf tissue is considered, reducing the temperature from 24°C to 14°C for 5 days slightly affected the pigment content, but violaxanthin was largely converted to zeaxanthin and antheraxanthin in the xanthophyll cycle. The results indicate that compared to old leaf tissue of mature leaves, physiologically younger leaf tissue of immature leaves is much more able to recover from depressions in the photosynthetic activity induced by growth at sub-optimal temperature when the plants experience optimal growth temperatures, but that factors other than the pigment content must determine this capability.     

牛角花齿蓟马成虫触角感器的扫描电镜观察

本研究旨在明确我国北方苜蓿重要害虫——牛角花齿蓟马Odontothrips loti触角感器类型、形态特征及分布特点。利用扫描电镜观察牛角花齿蓟马雌、雄成虫触角的超微结构,比较雌、雄虫之间的差异。结果表明：牛角花齿蓟马雌虫触角长度（314.42±7.21 μm）明显较雄虫（260.58±5.69 μm）长,除柄节和第I鞭节外,其他各节雌虫均较雄虫粗大。牛角花齿蓟马成虫触角感器类型共有7种,即Bhm氏鬃毛（BB）、刺形感器（SChI, SChII）、锥形感器（SBI, SBII, SBIII）、钟形感器（SCa）、腔锥形感器（SCo）、腔形感器（SCav）和毛形感器（ST）,雌虫触角上述7种类型感器均有分布,而雄虫触角上未发现腔形感器。牛角花齿蓟马成虫触角感器在类型、形态特征及分布方面表现雌、雄个体差异。本研究为深入探究牛角花齿蓟马触角感器的嗅觉通讯机制提供形态学基础。