Fresh and dry wei ghts of Mononychellus tanajoa (Acari: Tetranychidae): A functional description of biomass accumulation

The fresh and dry weights of each life stage of Mononychellus tanajoa (Bondar) were determined using grouped samples. The eggs, larvae and protonymphs averaged 0.637, 0.625 and 1.013 μg fresh weight, respectively. Male and female deutonymphs averaged 1.209 and 2.715 μg, while male and female adults averaged 1.633 and 7.035 μg fresh weight, respectively. The dry matter content of M. tanajoa across all life stages for both sexes averaged 31%. The accumulation of biomass in male and female M. tanajoa is adequately described by logistic growth functions (with 87 and 98% explained variation, respectively). Maximum growth rates of 0.026 and 0.598 μg dry matter per day for males and females, respectively, were estimated using these fitted functions.     

Construction costs and mesostructure of leaves in hydrophytes

Construction costs (CC) and parameters of leaf structure (specific leaf weight, dry matter content, volume of photosynthesizing cells, and the number of cells per leaf area unit) were determined for 19 species of aquatic higher plants. The CC of 1 g dry matter varied from 0.98 g glucose in Lemna gibba L. to 1.48 g glucose in Nuphar pumila (Timm) DC. and Potamogeton natans L. The CC of leaf area unit varied to a greater extent than the CC of 1 g dry wt (from 10 to 97 g glucose/m²) and depended on the type of mesophyll structure. In leaves of hydrophytes with dorsoventral mesophyll structure, the CC of 1 m² leaf area was 3–9 times larger than in leaves with homogeneous structure. Variations in CC of 1 m² leaf area in hydrophytes were affected insignificantly (by 2% only) by variations of CC per 1 g dry wt and were mainly determined (by 82%) by changes in specific leaf weight. Two-factor analysis of variance has shown that the CC of 1 g dry wt in hydrophytes depended on the attachment of plants to the sediment: the CC was 1.2 times larger in rooted hydrophytes than in free floating plants. The second factor (the extent of submergence) potentiated the effect of rooting on CC. Reliable differences were found between the leaf CC for hydrophytes belonging to four groups distinguished by the extent of their contact with water and sediment. In a group series: rooted hydrophytes with floating leaves → submerged rooted hydrophytes → free floating submerged hydrophytes → free floating surface inhabiting hydrophytes, the CC of 1 g dry wt decreased by 1.3 times. Path analysis has shown that this trend was due to the increase in photosynthesizing cell volume and to reduction in number of cells per leaf area unit, which caused the decrease in dry matter content. The decrease in the content of leaf dry matter was accompanied by changes in its chemical composition: the content of carbon and nitrogen decreased. This led to a consistent decrease in leaf CC expressed per 1 g dry wt upon the increase in extent of plant hydrophilicity.     

Anaerobic Production of Thiobacillus denitrificans for the Enzyme Rhodanese

A method for the anaerobic growth of Thiobacillus denitrificans in a 140-liter (total capacity) stainless-steel culture vessel is described. As a result of controlling the pH value of cultures, and of ensuring that certain essential nutrients were in excess, cell yields approaching 700 mg (dry weight) per liter were obtained. These were over threefold higher than the best yields hitherto reported. The average rhodanese content of the cells from four cultures was 176,000 units per gram (dry weight). Adenosine-5′-phosphosulfate reductase (average content, 238 units per gram dry weight) and adenylate kinase (average content, 15,300 units per gram, dry weight) were also present.     

Seasonal variation in the energy content of benthic macroinvertebrates of Lake Nainital,U.P., India

The paper discusses seasonal variation in the energy contents of four macrobenthic invertebrates of Lake Nainital during 1977–78. The energy values varied from 16971–19437 J/g dry weight in Tubifex tubifex, 16 511–20 231 J/g dry weight in Glossiphonia weberi, 19 019–25 289 J/g dry weight in Chironomus plumosus and 19 583–20 549 J/g dry weight in Viviparus bengalensis. The former two genera exhibited highest energy contents during summer, whereas the latter two revealed highest values during winter. On mean annual basis, the highest values were recorded for C. plumosus and lowest for T. tubifex. In V. bengalensis, variation occurred in ash fraction (%) and in energy values (Joule per gram dry weight) but not in energy values of organic fraction (Joule per gram ash-free dry weight), while the other three genera displayed variation in all three variables.     

Influence of manganese deficiency and toxicity on isoprenoid syntheses

Twenty-eight day old wheat (Triticum aestivum L. cv Stacy) response to varying Mn concentration (10.1-10,000 micromolar) in nutrient solution was measured. Manganese concentrations in the most recently matured leaves (blade 1) were 0.21 to 19.03 mmol Mn per kilogram dry weight, respectively. Fresh and dry weights increased to a maximum at the 5 micromolar Mn nutritional level (0.37 millimole Mn per kilogram dry weight) and were decreased at Mn above and below this concentration. Blade 1 chloroplast pigment concentrations increased up to the 20 micromolar Mn nutritional level (1.98 millimole Mn per kilogram dry weight) and decreased at higher Mn concentrations. Thylakoid Mn content was above 1 mole Mn/100 mole chloroplast at Mn nutrition levels which resulted in greatly decreased plant growth. Total phytoene biosynthesis was decreased by Mn deficiency and toxicity. In vitro ent- kaurene synthesis was greatly influenced by Mn concentration with a maximal biosynthesis at 1 micromolar Mn and decreases at Mn levels above and below this concentration. In vivo blade 1 gibberellic acid equivalent concentrations were maximal at 20 parts per million Mn nutrition solution levels (1.98 millimole Mn per kilogram dry weight) and decreased at Mn tissue concentrations above and below this value; additionally, gibberellic acid concentrations were reciprocal to extracted C₂₀ alcohol concentrations. Mn influence on gibberellin and chloroplast pigment biosyntheses exactly matched the measured changes in growth.     

Production of tocopherols by cell culture of safflower

A new method for the production of tocopherols by safflower (Carthamus tinctorius) cell culture has been developed. The main tocopherol produced is α-tocopherol which has the strongest vitamin E activity among tocopherol analogues. In a time course experiment tocopherol production showed a secondary metabolic pattern rather than a primary one. Better cell lines in terms of both growth rate and amounts of tocopherols produced were obtained by selection using various growth regulators and media additives. In addition, tocopherol production was effectively stimulated by administration of biosynthetic precursors. In particular, phytol increased the total tocopherol content by some 18-fold, i.e. 63.6 mg per 100 g dry weight, and the α-tocopherol content by some 11- fold i.e. 28.8 mg per 100 g dry weight.     

Leaf non-structural carbohydrates and leaf dry weight per area in three altitudinal populations ofEspeletia schultzii WEDD

The leaf non-structural carbohydrate (NSC) content and total non-structural carbohydrate content (TNC) were measured on a dry weight basis and on a leaf area basis in three altitudinal (3100, 3550 and 4200 m a.s.l.) populations ofE. schultzii. The values of leaf dry weight per area (LWA) increase with altitude. The leaf non-structural carbohydrate content (expressed as g/kg dry weight) does not show statistically significant difference among populations, but the values expressed on an area basis (g/m²) show a statistically significant increase with altitude. Significant correlations were observed between LWA and TNC (r ²=0.65); insoluble carbohydrate (r ²=0.78); total soluble carbohydrate (r ²=0.53); reducing sugars (r ²=0.47) expressed on area basis. Correlations between LWA and NSC for any fraction and TNC on a dry weight basis were not significant. It appears that along this altitudinal gradient the leaf area is more affected than the leaf dry weight. Since the NSC is known to play a role in the freezing tolerance of plants, the results indicate that the freezing tolerance does not change among the populations along the gradient.     

Analysis of the ash of the seeds ofAesculus hippocastanum and someAceres

The seeds contain such a high percentage of phosphoric acid that it interferes with the obtaining of correct results in analysis. Its prior removal from the solution of ash is therefore necessary. A new method is suggested for the entire analysis which is a combination of percolation through an ionexchanger column and colorimetric and gravimetric determination. The oxide values and the average content of ash per 100 g. dry weight of seeds ascertained by analysis were used to calculate the weight of each determined element per 100 g. of dried substance. The analysis showed that traces of tin are present in the ash of the seeds tested. Under the given conditions each species maintains its characteristic way of storing ash constituents in the seeds and this is not obviously affected by the affinity of the plants or the influence of the soil.     

Life-cycles of three populations of Potamogeton pectinatus L. at different degrees of wave exposure in the Askö area,Northern Baltic proper

Potamogeton pectinatus L. populations were studied at three stations over an annual cycle.The maximum standing crop of 17.5 g dry weight (wt.) m⁻² was recorded a the most sheltered station, decreasing slightly at the intermediate station to 15.8 g dry wt.m⁻², and being only 4.8 g dry wt.m⁻² at the most exposed station.Flowering and seed production occurred at all three stations. The maximum proportion of dry weight allocated to reproduction was higher at the more exposed stations (4%), while at the sheltered station only 1% was allocated to reproductive parts. The number of overwintering tubers produced per m² decreased from 115 per m² to 45 per m² with lowered exposure. Conversely, the number of flowers per inflorescence and flowers per m² was highest at the most sheltered station, decreasing from 9 to 6 and 945 to 672 per m², respectively, with increasing exposure. No definite trend could be found for seed production, which was highly variable and dependent on a successful period of fertilization during calm weather. At the sheltered locality more resources were allocated to vegetative shoots and rhizomes which were also able to overwinter.The resource allocation of Potamogeton pectinatus seems to be strongly influenced by environmental factors. This is discussed in relation to current reproductive strategy concepts.     

Water Content during Abscisic Acid Induced Freezing Tolerance in Bromegrass Cells

Changes in water content and dry weight were determined in control cells and those induced to cold harden in response to abscisic acid (ABA) treatment (7.5 × 10⁻⁵ molar). Bromegrass (Bromus inermis Leyss cv Manchar) cells grown in suspension culture at room temperature (23°C) for 7 days acclimated to −28°C (LT₅₀) when treated with ABA, or to −5°C when untreated. ABA significantly reduced cell growth rates at 5 and 7 days after treatment. Growth reduction was due to a decrease in cell number rather than cell size. When the cell water content was expressed as percent water (percent H₂O) or as grams water per gram dry weight (gram H₂O/gram dry weight [g DW]), the water content of hardy, ABA-treated cells decreased from 85% to 77% or from 6.4 to 3.3 g H₂O/g DW in 7 days. Control cell water content remained static at approximately 87% and 7.5 g H₂O/g DW. However, cell water content, expressed as milligrams water per million cells (milligram H₂O/10⁶ cells), did not differ in ABA-treated or control cells. The dry matter content of ABA-treated cells, expressed as milligram DW/10⁶ cells increased to 3.3 milligram/10⁶ cells in 7 days, whereas the dry weight of the control cells remained between 1.4 to 2.1 milligrams/10⁶ cells. The osmotic potential of ABA-treated cells decreased by the fifth day while that of control cells increased significantly and then decreased by day 7. Elevated osmotic potentials were not associated with increased ion uptake. In contrast to much published literature, these results suggest that cell water content does not decrease in ABA-treated cells during the induction of freezing tolerance, rather the dry matter mass per cell increased. Cell water content may be more accurately expressed as a function of cell number when accompanying changes to dry cell matter occur.     

Leaf Photosynthesis and Respiration of High CO(2)-Grown Tobacco Plants Selected for Survival under CO(2) Compensation Point Conditions

Four self-pollinated, doubled-haploid tobacco, (Nicotiana tabacum L.) lines (SP422, SP432, SP435, and SP451), selected as haploids by survival in a low CO₂ atmosphere, and the parental cv Wisconsin-38 were grown from seed in a growth room kept at high CO₂ levels (600-700 parts per million). The selected plants were much larger (especially SP422, SP432, and SP451) than Wisconsin-38 nine weeks after planting. The specific leaf dry weight and the carbon (but not nitrogen and sulfur) content per unit area were also higher in the selected plants. However, the chlorophyll, carotenoid, and alkaloid contents and the chlorophyll a/b ratio varied little. The net CO₂ assimilation rate per unit area measured in the growth room at high CO₂ was not higher in the selected plants. The CO₂ assimilation rate versus intercellular CO₂ curve and the CO₂ compensation point showed no substantial differences among the different lines, even though these plants were selected for survival under CO₂ compensation point conditions. Adult leaf respiration rates were similar when expressed per unit area but were lower in the selected lines when expressed per unit dry weight. Leaf respiration rates were negatively correlated with specific leaf dry weight and with the carbon content per unit area and were positively correlated with nitrogen and sulfur content of the dry matter. The alternative pathway was not involved in respiration in the dark in these leaves. The better carbon economy of tobacco lines selected for low CO₂ survival was not apparently related to an improvement of photosynthesis rate but could be related, at least partially, to a significantly reduced respiration (mainly cytochrome pathway) rate per unit carbon.     

Changes in the chlorophyll and carotenoid contents in the leaves of steppe plants along a latitudinal gradient in South Ural

We studied the content of chlorophylls and carotenoids in the leaves of steppe plants of South Ural growing along a latitudinal gradient from southern steppe to forest-steppe. The content of chlorophylls (a + b) was 5–6 mg per 1 g of the leaf dry weight and did not depend on the latitude, whereas the content of carotenoids in the leaves increased northward from 1.0 to 1.5 mg/g dry wt. At the same time, the greatest changes occurred in the ratios between the forms of pigments: the chlorophyll a/b ratio increased from 1.8 to 2.8, and the chlorophyll/carotenoid ratio decreased from 5.6 to 3.5. The obtained results indicate that adaptation of the pigment apparatus of steppe plants growing along the latitudinal gradient occurs due to the transformation of the light-harvesting complex.     

Cultivation of Lemna gibba under desert conditions. I: Twelve months of continuous cultivation in open ponds

Duckweed, Lemna gibba, was grown in 12 m² shallow ponds in the Negev desert, during 12 months of continuous cultivation, beginning April 1984. Average monthly growth rates varied with the season of the year. The lowest daily yield, 2·6±0·4 g dry weight m⁻² day⁻¹, was obtained during January. Highest daily yields, 7·9±2·6 g dry weight m⁻² day⁻¹ and 7·0±1·2 g dry weight m⁻² day⁻¹, were obtained during September and May. A 35% decline of the yield was seen during midsummer (July), 4·8±1·2 g dry weight m⁻² day⁻¹. The average rate for the year was 5·15±1·7 g dry weight m⁻² day⁻¹. The protein content of the plants ranged from 30 to 38% per unit dry weight.Growth performance is discussed in relation to the prevailing climatic conditions.     

Bioaccumulation and distribution of mercury in the hard clam,Meretrix lusoria (Bivalvia:Veneidae)

1. Total mercury concentration in whole soft parts of the hard clam, Meretrix lusoria, increased significantly with increasing exposure concentrations. It reached 4.247–7.084 and 9.956–13.643 μg T-Hg/g dry weight in 5 and 50 μg/l Hg mercury solution, respectively, against a background level of 1.824–0.577μg T-Hg/g dry weight.2. Bioconcentration factor was 4–6 times higher in 5 μg/l Hg than that of 50 μg/l Hg. An estimated biological half-life of 20.2 and 18.4 days in 5 and 50 μg/l Hg, respectively, were also obtained after 14 days uptake.3. Accumulation of mercury in tissues of the clams was greater in the gills and viscera than in the mantle, adductor, foot, or hemolymph.4. The amount of mercury present in the gills is related to be a linear relationship with the mercury content of viscera.     

Mitochondria in the flight muscles of insects. III. Mitochondrial cytochrome c in relation to the aging and wing beat frequency of flies

1. In the present study a correlation has been sought between aging, flight muscle mitochrondria (sarcosomes), cytochrome c, and flight ability in the blowfly, Phormia regina. 2. During the 1st week of adult life, individual sarcosomes increase in mass from 2.7 x 10^–7 µg. dry weight at the time of emergence, to 8.5 x 10^–7 µg. by the 7th day. During this period of growth, the number of sarcosomes per fly (6.7 x 10⁸) remains constant. When mature, the sarcosomes account for 32.6 per cent of the total muscle dry weight, or close to 40 per cent on a wet weight basis. 3. It appears probable that the high content of flight muscle cytochromes is entirely localized in the sarcosomes. The cytochromes continue to be synthesized and increase in titer within the sarcosomes for 7 days after adult emergence. 4. As determined spectroscopically, the various cytochrome components at all times maintain a constant ratio both to one another and to the sarcosomal dry weight. This suggests the possibility that the cytochrome system may be synthesized as a single entity. 5. The wing-beat frequency of Drosophila funebris and Phormia varies with the age of these flies, being lowest at the time of emergence and maximum after the 6th day. 6. The relations between wing-beat frequency, respiration during flight, and sarcosomal cytochrome c content are discussed. On the basis of some likely assumptions it is calculated that the cytrochrome c turnover number is over 5,000, and that the cytochrome c turns over once for every two wing-beat cycles.     

Variation of bioactive substances and morphological traits in Hypericum perforatum populations from Northern Turkey

Hypericum perforatum L. has become one of the leading plant-based dietary supplements worldwide and its biological activities have been mainly attributed to hypericin and phenolic contents. The present study was conducted to determine chemical and morphological variability of H. perforatum sampled from different locations of Northern Turkey. The populations were investigated according to the hypericin, chlorogenic acid and the flavonoids, namely rutin, hyperoside, apigenin-7-O-glucoside, quercitrin and quercetin contents and morphological characters including leaf dark gland density, leaf area, leaf length/width ratio and plant height. Significant chemical and morphological variations were detected among the populations. Hypericin content among populations ranged between 0.44 and 2.82 mg/g dry weight, chlorogenic acid between 0.0 and 1.86 mg/g dry weight, rutin between 0.0 and 8.77 mg/g dry weight, hyperoside between 5.41 and 22.28 mg/g dry weight, quercitrin between 1.64 and 3.98 mg/g dry weight and quercetin between 1.01 and 1.76 mg/g dry weight. Hypericin content was found to be correlated positively with leaf dark gland density, however, negatively with leaf area and no correlation was detected between the other morphological traits and bioactive substances examined.     

Carbohydrate Status of Tulip Bulbs during Cold-Induced Flower Stalk Elongation and Flowering

The effect of a cold treatment on the carbohydrate status of the scales and flower stalk of Tulipa gesneriana L. cv Apeldoorn bulbs during growth after planting was studied and compared with bulbs not given cold treatment. Bulbs were stored dry for 12 weeks at 5[deg]C (precooled) or 17[deg]C (noncooled). Only the 5[deg]C treatment led to rapid flower stalk elongation and flowering following planting at higher temperatures. Precooling enhanced mobilization of starch, fructans, and sucrose in the scales. The cold-stimulated starch breakdown was initially accompanied by increased [alpha]-amylase activity per scale. In noncooled bulbs, [alpha]-amylase activity slightly decreased or remained more or less constant. Cold-induced flower stalk elongation was partially accompanied by a decrease in the sucrose content and an increase in the glucose content and invertase activity per g dry weight. The starch content in internodes initially decreased and subsequently increased; [alpha]-amylase activity per g dry weight of the lowermost internode showed a peak pattern during starch breakdown and increased thereafter. The internodes of noncooled bulbs, on the contrary, accumulated sucrose. Their glucose content and invertase activity per g dry weight remained low. Starch breakdown was not found and [alpha]-amylase activity per g dry weight of the lowermost internode remained at a low level. Precooling of tulip bulbs thus favors reserve mobilization in the scales and flower stalk and glucose accumulation in the elongating internodes.     

不同采集时间芒萁各部位总黄酮含量的动态变化

芒萁〔Dicranopteris pedata（Houtt.）Nakai〕又称铁狼萁,为里白科（Gleicheniaceae）芒萁属（Dicranopteris Bernh.）多年生草本植物,广泛分布于中国长江以南各省区,是常用药用蕨类植物,也是林区酸性土的指示植物[1-2]。黄酮类成分是芒萁的主要药用成分,具有抗菌消炎、抗氧化、降压、清热解毒、防止血管增生和抑制脂肪氧化酶等多种活性[3-7],在治疗冠心病、抗癌防癌和消除自由基等方面[8-11]也有显著功效,     

Assessment of the physiological state of the common carp Cyprinus carpio L. by the water content in the organism

A simple method is proposed for distinguishing between two levels of the physiological state of the common carp by the water content in the organism. It is shown that low water content (2.61 ± 0.04 g H₂O per 1 g of dry weight, 72.3 ± 0.27%) in the body of the fish is associated with a state providing for the growth of the organism. Higher water content (3.63 ± 0.06 g H₂O per 1 g of dry weight, 78.4 ± 0.26%) in the body of the fish is associated with a physiological state that helps it survive through environmental conditions unfavorable for the growth of the organism.     

Effects of deep seawater medium on growth and amino acid profile of a sterile Ulva pertusa Kjellman (Ulvaceae, Chlorophyta)

The potential use of deep seawater (DSW) for the cultivation of macroalgae was evaluated by analysis of the growth rate of thalli (by surface area), photosynthetic pigment content, and total free amino acid content of sterile Ulva pertusa cultured in the control medium (one-fifth strength Provasoli’s enriched seawater (PES) medium), surface seawater (SSW) medium and also seawater medium collected from 400 m depth (400-DSW) and 1,200 m depth (1,200-DSW). The growth rate of the sterile U. pertusa grown in 400-DSW and 1,200-DSW was similar to that of thalli cultured in the one-fifth strength PES medium that had previously been shown to be the optimum concentration for the cultivation of Ulva. Photosynthetic pigment content in the control medium, 400-DSW- and 1,200-DSW-cultured thalli was 1.7–2.0 times higher than that of the SSW-cultured thalli. The total free amino acids content of the control medium and SSW-cultivated thalli was 264?±?64 and 120?±?39 mg per 100 g dry weight, whereas the 400-DSW- and 1,200-DSW-cultivated thalli had significantly more amino acids (342?±?69–327?±?64 mg per 100 g dry weight). The results of this study indicate that DSW has a high potential for cultivation of edible macroalgae without any supply of extra nutrient until it grows to harvest size.