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1.
Browse tree leaves of six species of Acacia (A. angustissima L., A. drepanolobium L., A. nilotica L., A. polyacantha L., A. senegal L., A. tortilis L.) were screened for chemical composition, including minerals and trace elements. Crude protein (CP) varied among the species from 145 (A. senegal) to 229 g/kg DM (A. angustissima). The species had moderate to high levels of minerals. The concentrations of Ca, P, Mg and S varied among the species from 14.6-31.5, 3.5-4.9, 1.4-3.0 and 1.7-2.8 g/kg DM, respectively. The forages showed relatively low concentrations of trace elements. Content of trace elements varied among the species from 4.5-23.8, 99.4-173.6, 146.2-432, 41.0-90.1, 10.9-22.2 and 0.05-0.65 mg/kg DM for Cu, Mo, Fe, Mn, Zn and Co, respectively. All leaves of browse species would meet the normal requirements for Ca, P, Mg and S in ruminants, although some species had higher levels of Ca than tabulated mineral requirements in livestock. Assayed Cu, Mn, Zn and Co would satisfy the lower range of recommended requirements of trace elements depending on their bioavailability. Therefore, browse leaves from Acacias could form good sources of CP and mineral supplements to ruminants.  相似文献   

2.
Browsing ruminants have access to different biomass, depending on how high they can reach. Foliage consisting of leaves and green pods from Acacia senegal, Pterocarpus lucens and Guiera senegalensis, was collected according to height above ground accessible to either sheep (0.90 m), goats (1.65 m) or cattle (1.50 m). There was a significant variation in the chemical composition of the biomass between species. The crude protein (CP) content was 114, 157 and 217 g/kg dry matter (DM) and the neutral detergent fiber (aNDF) content 604, 534 and 412 g/kg DM for G. senegalensis, P. lucens and A. senegal, respectively. There was no significant variation in chemical composition according to the height accessible by cattle, sheep or goats. The voluntary intake was studied using eight goats per diet. The six diets consisted of the three browse leaves and two pods (A. senegal and P. lucens) and a control. The leaves were fed combined with hay of Schoenefeldia gracilis (maximum 30%) and the control was pure hay. Apparent digestibilities of the same diets, with the exception of G. senegalensis, were measured using five goats per diet. All browse fodders used in the feeding and digestibility trials were high in CP (105–170 g/kg DM) and lignin (164–234 g/kg DM except A. senegal leaves) and low in fiber (322–590 g/kg DM of NDF) compared to the hay (31 g/kg DM of CP and 755 g/kg DM of NDF). The highest intake was of the P. lucens diet (864 g) and the lowest of the G. senegalensis diet (397 g). The intake of pods from A. senegal was higher (1033 g) than from P. lucens pods (691 g). The apparent digestibility of OM and CP in the browse leaves was 0.63 and 0.57 and 0.63 and 0.64 for A. senegal and P. lucens, respectively, higher than for the hay, which showed higher digestibility of NDF. A. senegal pods had higher digestibility for all nutrients than P. lucens pods. Based on the high CP content and the intake and digestibility characteristics, P. lucens leaves and A. senegal leaves and pods can be recommended as protein supplements to low quality diets.  相似文献   

3.
Trace elements in soils exist as components of several different fractions. We have analyzed the correlation between total and extractable (EDTA, calcium chloride and deionized water) Zn, Pb and Cu concentrations in soils and the concentration of these elements in plant leaves. Soil and plant samples have been taken from Sulcis-Iglesiente (Sardinia), an area rich in mining tailings. This has made that the concentrations of the trace element under study in soils were varied. Three plants have been studied: Dittrichia viscosa, Cistus salviifolius, and Euphorbia pithyusa subsp. cupanii. Soil samples beneath each of them at depths of 0–30 and 30–60 cm have been considered. The highest concentration of trace elements in the leaves of the studied species has been found for Zn. The calcium carbonate content and the crystalline and amorphous forms of iron in the soil have determined the concentration of metal in plant leaves. The soil concentrations that have been found with the extraction methods are uncorrelated with Pb and Cu concentrations in plants, but Zn is correlated with the fraction extracted with EDTA and calcium chloride. The concentrations of trace metals in plants are most closely related to the soil contents of CaCO3, electrical conductivity, Feox, and Fedc.  相似文献   

4.
The nutrient content and intake of locally available North Carolina browse was evaluated for use as a supplement to a herbivorous primate diet of commercial biscuit and produce. Twice weekly from May to October 1997, total dietary intakes were determined for two groups of folivorous lemurs. Group I consisted of Propithecus diadema diadema (n = 1) and P. tattersalli (n = 1) and group II consisted of P. verreauxi coquereli (n = 3). Six pooled samples of the diet and weekly samples of three browse species, Rhus copallina, Albizia julibrissin, and Liquidamber styrachiflua were analyzed for dry matter, energy, fiber, and nitrogen content. Browse species were also analyzed for nonprotein nitrogen and acid‐insoluble nitrogen. Group average dry matter intakes were 37.1 ± 2.2% (mean ± SEM) and 49.7 ± 3.0% of amount offered for groups I and II, respectively. Browse contributed 40.7 ± 2.9% and 29.6 ± 2.4% of the total daily intake for groups I and II, respectively. Browse species differed (P < 0.05) for dry matter, energy, neutral detergent fiber, acid detergent fiber, cellulose, lignin, total nitrogen, nonprotein nitrogen, available nitrogen, and available protein. R. copallina and L. styrachiflua were similar in total nitrogen, available nitrogen, and nonprotein nitrogen; A. julibrissin was higher. L. styrachiflua was highest in lignin. Dry matter, acid detergent fiber, and lignin in browse samples increased seasonally (P < 0.05), whereas available protein decreased (P < 0.01). Animals were offered and consumed R. copallina most often, followed by A. julibrisson and L. styrachiflua. With the exception of R. copallina, animals generally consumed only the immature leaves, flowers, or seeds of species offered. Daily dry matter intake varied because of both browse offered and consumed and biscuit and produce diet consumed. Thus, increased fiber density can be a major benefit of browse use only when incorporated into the total diet with respect to species use, quantity of other diet ingredients offered, and targeted nutrient intakes. Zoo Biol 20:447–461, 2001. © 2002 Wiley‐Liss, Inc.  相似文献   

5.
The aim of this study was to determine the chemical composition of eight invertebrate species and evaluate their suitability as alternative prey. The species selected were rusty red cockroaches (Blatta lateralis), six‐spotted cockroaches (Eublaberus distanti), Madagascar hissing cockroaches (Gromphadorhina portentosa), fruit flies (Drosophila melanogaster), false katydids (Microcentrum rhombifolium), beetles of the mealworm (Tenebrio molitor), and superworm beetles (Zophobas morio), as well as woodlice (Porcellio scaber). Dry matter (DM), crude protein, crude fat, neutral detergent fiber, acid detergent fiber, ash, macro and trace minerals, vitamins A and E, and carotenoid concentrations were quantified. Significant differences were found between species. Crude protein content ranged from 38 to 76% DM, fat from14 to 54% DM, and ash from 2 to 8% DM. In most species, calcium:phosphorus was low (0.08–0.30:1); however, P. scaber was an exception (12:1) and might prove useful as a dietary source of calcium for insectivores. Vitamin E content was low for most species (6–16 mg/kg DM), except for D. melanogaster and M. rhombifolium (112 and 110 mg/kg DM). The retinol content, as a measure of vitamin A activity, was low in all specimens, but varied greatly among samples (0.670–886 mg/kg DM). The data presented can be used to alter diets to better suit the estimated requirements of insectivores in captivity. Future research on the topic of composition of invertebrate prey species should focus on determination of nutrient differences owing to species, developmental stage, and diet. Zoo Biol 31:40;–54, 2012. © 2011 Wiley Periodicals, Inc.  相似文献   

6.
Metal removal potential of indigenous mining microorganisms from acid mine drainage (AMD) has been well recognised in situ at mine sites. However, their removal capacity requires to be investigated for AMD treatment. In the reported study, the capacity of an indigenous AMD microbial consortium dominated with Klebsormidium sp., immobilised in a photo-rotating biological contactor (PRBC), was investigated for removing various elements from a multi-ion synthetic AMD. The synthetic AMD was composed of major (Cu, Mn, Mg, Zn, Ca, Na, Ni) and trace elements (Fe, Al, Cr, Co, Se, Ag, Mo) at initial concentrations of 2 to 100 mg/L and 0.005 to 1 mg/L, respectively. The PRBC was operated for two 7-day batch periods under pH conditions of 3 and 5. The maximum removal was observed after 3 and 6 days at pH 3 and 5, respectively. Daily water analysis data demonstrated the ability of the algal–microbial biofilm to remove an overall average of 25–40 % of the major elements at pH 3 in the order of Na?>?Cu?>?Ca?>?Mg?>?Mn?>?Ni?>?Zn, whereas a higher removal (35–50 %) was observed at pH 5 in the order of Cu?>?Mn?>?Mg?>?Ca?>?Ni?>?Zn?>?Na. The removal efficiency of the system for trace elements varied extensively between 3 and 80 % at the both pH conditions. The batch data results demonstrated the ability for indigenous AMD algal–microbial biofilm for removing a variety of elements from AMD in a PRBC. The work presents the potential for further development and scale-up to use PBRC inoculated with AMD microorganisms at mine sites for first or secondary AMD treatment.  相似文献   

7.
In this study, HPLC-MS and ICP-MS methods were used for the determination of histidine and nickel in Morus L., Robinia pseudoacacia L., and Populus nigra L. leaves taken from industrial areas including Gaziantep and Bursa cities. In the determination of histidine by HPLC-MS, all of the system parameters such as flow rate of mobile phase, fragmentor potential, injection volume and column temperature were optimized and found to be 0.2 mL min?1, 70 V, 15 µL, and 20°C, respectively. Under the optimum conditions, histidine was extracted from plant sample by distilled water at 90°C for 30 min. Concentrations of histidine as mg kg?1 were found to be between 2–9 for Morus L., 6–13 for Robinia pseudoacacia L., and 2–10 for Populus nigra L. Concentrations of nickel were in the ranges of 5–10 mg kg?1 for Morus L., 3–10 mg kg?1 for Robinia pseudoacacia L., and 0.6–4 mg kg?1 for Populus nigra L. A significant linear correlation (r = 0.78) between histidine and Ni was observed for Populus nigra L., whereas insignificant linear correlation for Robinia pseudoacacia L. (r = 0.22) were seen. Limits of detection (LOD) and quantitation (LOQ) were found to be 0.025 mg Ni L?1 and 0.075 mg Ni L?1, respectively.  相似文献   

8.
The significant threats to the fewer than 30 wild Dicerorhinus sumatrensis harrissoni, the Bornean sub‐species of the Sumatran rhinoceros, are obvious and include poaching, habitat loss, and environmental changes. Subtle effects on population survival, however, include nutritional or other diseases, which affect morbidity and reproductive success. To address these issues and focus on animals within their natural range, this feeding trial and analysis characterizes the diet fed to the only three captive D. s. harissoni in the world housed at the Sumatran Rhino Breeding Center (SRBC) in Sabah, Malaysia. The study provides an indication of the variance in nutrient composition in local browse, and a comparison with other captive feeding studies. Mean dry matter intake (DMI), comprising ∼90% native browse species, equaled 3.55% (range=2.8–4.1%) of body mass, with a dry matter digestibility averaging 82%. The mean crude protein content of native browses (n=8 spp.) averaged 11.2% (DM basis; range=5–23%, depending on plant part), with available protein measured at 7.8%. Leaves contained significantly (P<0.001) more crude protein, and less (P<0.001) fiber (neutral detergent fiber, acid detergent fiber, and lignin) than twig fractions analyzed, but animals consumed both fractions rather non‐selectively. Of minerals quantified, Na and P were potentially limiting in native browses compared to equid nutrient requirements, and Se may have been marginal. Ca, K, and Fe levels in particular were high in most native browses. Specifically, iron ranged from 45–1,400 mg/kg (mean=230 mg/kg DM), with only three preferred species containing this nutrient at <100 mg/kg. Excess dietary iron has been linked with health issues in browsing rhinos. Additionally, high levels of other minerals (for example Mn, with a mean of 382 mg/kg DM in this study), can precipitate deficiencies in crucial elements such as calcium. In view of the structural and chemical variations of the different parts of the same plants, dietary guidelines should be developed and incorporated into the basic husbandry of these animals that include increasing the number and combinations of species of browse offered daily to adjust for variance in protein, fiber, other nutritional components and food preference, to increasing the quantity of food offered per day based on desired weight gain and reproductive status. This, combined with information on the free‐ranging rhinoceros diet composition, and additional intake and digestibility trials (with concurrent serum analysis to evaluate nutritional status) should greatly assist in providing optimal diets for this highly endangered species. Zoo Biol 0:1–15, 2006. © 2006 Wiley‐Liss, Inc.  相似文献   

9.
Browse plants play an important role in providing feed for livestock in semi-arid rangelands of Africa. Chemical composition and in vitro ruminal fermentation of leaves collected from Acacia burkei, Acacia tortilis, Acacia nilotica, Dichrostachys cinerea and Ehretia obtusifolia in communal grazing lands in the lowveld of Swaziland is presented. Leaves were collected from trees located on two soil types (i.e., lithosol and vertisol) in the communal land but it had no effect on the chemical composition of tree leaves. The NDFom and ADFom content were highest in D. cinerea and A. burkei and lowest in E. obtusifolia and A. nilotica. Crude protein (CP) contents ranged between 108 g/kg and 122 g/kg DM. D. cinerea had the highest Ca and Mg content, while A. tortilis had the lowest. There were marked variations in K level amongst browse species, with A. tortilis (9.1 g/kg DM) having the highest value. The P, Zn and Fe did not differ between browse species. Soil type and tree species interaction impacted in vitro fermentation parameters. Extent of fermentation, as measured by 48 h cumulative gas production, and organic matter degradability was highest in E. obtusifolia leaves and lowest in D. cinerea leaves within soil type. Fermentation efficiency, as measured by partitioning factors, was highest in A. nilotica leaves. Leaves of E. obtusifolia could be a valuable supplementary feedstuff for ruminant livestock due to its in vitro fermentation characteristics as well as low fibre and moderate CP levels.  相似文献   

10.
It is recommended that browse should be an important part of diets for browsing and intermediate feeding type ruminants. However, provision of browse in winter time is problematic for many zoos located in the temperate climate. Drying or freezing of branches are commonly practiced solutions to this problem, but ensiling of tree leaves could also be an attractive option. The aim of this study was to determine the effect of drying and ensiling of different tree leaves on preference of their intake by nyala antelope (Tragelaphus angasii), an intermediate feeding type ruminant. A study was conducted on five nyala fed a standard diet (meadow hay, dehydrated chopped lucerne and limited concentrates) before and during the study. Preference of intake of five feeds was tested: dried maple (A. platanoides), oak (Q. robur), willow (S. alba), and ensiled maple and lime (T. cordata) leaves. Each day two tested feeds were offered to each animal. After 4 h of presentation, feed refusals were weighed and preference ratio for each tested feed and animal was calculated. Then, preferences were ranked using a pairwise comparison chart. Dried maple and oak leaves were preferred more than other leaves whereas ensiled lime leaves were the least preferred. On the other hand, ensiled and dried maple leaves were equally preferred. Results of this study showed that palatability of ensiled tree leaves should not be a concern when feeding nyala, and likely also other browsing or intermediate feeding type ruminants, but palatability of silage may depend on the species of tree.  相似文献   

11.
Nickel (Ni) phytoextraction using hyperaccumulator plant species to accumulate Ni from mineralized and contaminated soils rich in Ni is undergoing commercial development. Serpentinite derived soils have a very low ratio of Ca/Mg among soils due the nature of the parent rock. In crop plants, soil Ca reduces Ni uptake and phytotoxicity, so it is possible that the low Ca of serpentine soils could limit hyperaccumulator plant tolerance of serpentine soils used for commercial phytomining. In this study, we investigated the effects of varied Ca concentration in the presence of high Mg characteristic of serpentine soils on Ni uptake and tolerance by serpentine-endemic species Alyssum murale Waldst. et Kit. and A. pintodasilvae T.R. Dudley in comparison with cabbage (Brassica oleracea L. var. capita) in a nutrient solution study. The levels of Ca and Mg used were based on serpentine and normal soils, and Ni was based on achieving over 1% Ni in Alyssum shoots in preliminary tests. Varied solution concentrations of Ni (31.6–1,000 μM for Alyssum, 1.0–10 μM for cabbage) and Ca (0.128–5 mM) were used in a factorial experimental design; 2 mM Mg was used to mimic serpentine soils. Alyssum spp. showed much greater tolerance to high Ni, high Mg, and low Ca solution concentrations than cabbage. For Alyssum spp., Ni induced phytotoxicity was only apparent at 1,000 μM Ni with relatively low and high Ca/Mg quotient. In the 1,000 μM Ni treatment, shoot Ni concentrations ranged from 8.18 to 22.8 g kg?1 for A. murale and 7.60 to 16.0 g kg?1 for A. pintodasilvae. Normal solution Ca concentrations (0.8–2 mM) gave the best yield across all Ni treatments for the Alyssum species tested. It was clear that solution Ca levels affected shoot Ni concentration, shoot yield and Ni translocation from root to shoot, but the relation was non-linear, increasing with increasing Ca up to 2 mM Ca, then declining at the highest Ca. Our results indicate that Ca addition to high Mg serpentine soils with very low Ca/Mg ratio may reduce Ni phytotoxicity and improve annual Ni phytoextraction by Alyssum hyperaccumulator species. Removal of shoot biomass in phytomining will require Ca application to maintain full yield potential.  相似文献   

12.
Trace element contamination of lands is a serious environmental problem that limits yield and threatens human health. To study the combined effect of high salinity and toxic levels of trace elements on halophytes, the performance of two marsh species, Atriplex halimus and Suaeda fruticosa, grown for 1 month with an irrigation solution supplemented with 200 mM NaCl and 400 μM Cd2+ or 400 μM Cu2+ was evaluated. The effect of the combined stress conditions on hormone signaling was also assessed. Biomass production and chlorophyll content decreased under Cd2+ stress in both species, whereas Cu2+ had a lower impact on plant performance. The different plant sensibilities to the two trace elements assayed indicate that each metal has a different effect on plants. Furthermore, the deleterious effect of metal toxicity was alleviated when NaCl was added to the irrigation solution, demonstrating that NaCl improves plant performance and tolerance of halophytic species to cope with trace element intoxication. Results show that both species accumulated important quantities of Cd2+ and Cu2+ in roots (Cd2+: 2,690–3,130 μg g?1 DW and Cu2+: 2,070–2,770 μg g?1 DW); this finding allows us to classify these species among the hyperaccumulator plants. Cd2+ and Cu2+ differently affected endogenous phytohormone contents in both species. Data suggest an essential involvement of roots on the regulation of tolerance to trace elements. Therefore, indole-3-acetic acid levels increased in roots of both species irrigated with high levels of Cd2+, which suggests that the auxin may stimulate root promotion and growth under these stress conditions. Other compounds, classically considered as “stress hormones” showed very different patterns of accumulation. Whereas, salicylic acid (SA) levels in roots and leaves increased in response to Cd2+, root contents of jasmonic acid (JA), and abscisic acid (ABA) decreased. In leaves, the rambling pattern of accumulation observed for JA and ABA suggested the lack of a specific role in regulation against trace element toxicity. Together, data suggest that SA could act as a specific signal that detects trace element toxicity, whereas JA and ABA promote general responses against abiotic stress.  相似文献   

13.
The study aimed to explore the relationship of six kinds of mineral elements and diabetes among adults in northeast China. A cross-sectional survey was conducted in Jilin Province, northeast China. A total of 366 males and 204 females aged 18 ~ 77 years from Jingyu town, Dongliao town, and Changling town were included using a multistage stratified random cluster sampling design. Data was obtained from face to face interview, physical examination, and laboratory measurement. We defined the normal people (3.9 ~ 6.0 mmol/L), impaired fasting glucose (IFG) individuals (6.1 ~ 6.9 mmol/L), and diabetes mellitus (DM) (> 7.0 mmol/L) according to the WHO diagnostic criteria. Kruskal-Wallis test, Spearman rank correlation, as well as binary logistic regression were used to analyze influencing factors. lg(Cu/Zn)was correlated with DM (OR 8.390; 95% CI of OR 1.272–55.347). The specific mineral elements such as Zn, Ca, as well as Cu/Zn ratio may be the potential risk factors for diabetes. So, the supplement or reduction of these elements is supposed to be told to IFG to prevent or delay the occurrence of diabetes or DM to avoid its complication.  相似文献   

14.
This study aims to investigate the behavior of Atriplex nummularia under field conditions, including its growth, periodic cuttings, salt extraction, and soil chemical properties monitored for 16 months. Three treatments were evaluated: soil cultivated with Atriplex pruned at 6 and 12 months after transplanting (MAT); soil cultivated with plants that were harvested only at the end of the experiment (16 MAT); and a control (uncultivated soil) with four replications. Soil samplings were taken at 0, 6, 12, and 16 MAT. The samples were taken at depths of 0–20, 20–40, 40–60, and 60–80 cm. Biometric variables for growth were monitored monthly. The shoot was divided into leaves, thin stems (≤3 mm diameter), and thick stems (>3 mm diameter) to determine its content of Ca, Mg, Na, K, and Cl. We concluded that pruning regime for Atriplex was efficient mainly because it stimulated regrowth of less lignified material (leaves and stems ≤3 mm). We found that elements extracted by plant tissue can be quantified accurately, making them valuable indicators of the efficiency of the recovery process. The use of the Atriplex is recommended because the the possibility of revegetating areas inhospitable to most species used in conventional farming.  相似文献   

15.
This study was conducted to create a nutritional database on brown seaweeds and to popularize their consumption and utilization in Iran. The fatty acid contents, amino acids profiles, and certain mineral elements composition of some brown seaweeds, Padina pavonica (L.) Thivy, Dictyota dichotoma (Huds.) J. V. Lamour., and Colpomenia sinuosa (Mert. ex Roth) Derbés et Solier were determined. Total lipid content ranged from 1.46 ± 0.38 to 2.94 ± 0.94 g · 100 g?1dry weight (dwt), and the most abundant fatty acids were C16:0, C18:1, C20:4 ω6, and C20:5 ω3. The unsaturated fatty acids predominated in all species and had balanced sources of ω3 and ω6 acids. Highest total polyunsaturated fatty acid (PUFA) levels occurred in C. sinuosa. The protein content of D. dichotoma was 17.73 ± 0.29 g · 100 g?1dwt, significantly higher than the other seaweeds examined. Among amino acids essential to human nutrition, methionine (Met; in D. dichotoma and P. pavonica) and lysine (Lys; in C. sinuosa) were present in high concentrations. The crude fiber content varied by 9.5 ± 11.6 g · 100 g?1dwt in all species. Chemical analysis indicated that ash content was between 27.02 ± 0.6 and 39.28 ± 0.7 g · 100 g?1dwt, and that these seaweeds contained higher amounts of both macrominerals (7,308–9,160 mg · 100 g?1dwt; Na, K, Ca) and trace elements (263–1,594 mg · 100 g?1dwt; Fe, Ni, Mn, Cu, Co) than have been reported for edible land plants. C. sinuosa had the highest amount of Ca, Fe, and a considerable content of Na was measured in P. pavonica.  相似文献   

16.
Abstract

The behavioural responses of greenhouse whitefly to substances of plant origin were investigated in laboratory and greenhouse conditions. The following species of plants were found to provide the most active chemicals to monitor and control greenhouse whitefly – laurel Laurus nobilis L., mullein Verbascum thapsus L., tansy Tanacetum vulgare L., wormwood Artemisia vulgare L.  相似文献   

17.
The chlorophyll (Chl) fluorescence induction kinetics, net photosynthetic CO2 fixation rates P N, and composition of photosynthetic pigments of differently light exposed leaves of several trees were comparatively measured to determine the differences in photosynthetic activity and pigment adaptation of leaves. The functional measurements were carried out with sun, half-shade and shade leaves of seven different trees species. These were: Acer platanoides L., Ginkgo biloba L., Fagus sylvatica L., Platanus x acerifolia Willd., Populus nigra L., Quercus robur L., Tilia cordata Mill. In three cases (beech, ginkgo, and oak), we compared the Chl fluorescence kinetics and photosynthetic rates of blue-shade leaves of the north tree crown receiving only blue sky light but no direct sunlight with that of sun leaves. In these cases, we also determined in detail the pigment composition of all four leaf types. In addition, we determined the quantum irradiance and spectral irradiance of direct sunlight, blue skylight as well as the irradiance in half shade and full shade. The results indicate that sun leaves possess significantly higher mean values for the net CO2 fixation rates P N (7.8–10.7 μmol CO2 m?2 s?1 leaf area) and the Chl fluorescence ratio R Fd (3.85–4.46) as compared to shade leaves (mean P N of 2.6–3.8 μmol CO2 m?2 s?1 leaf area.; mean R Fd of 1.94–2.56). Sun leaves also exhibit higher mean values for the pigment ratio Chl a/b (3.14–3.31) and considerably lower values for the weight ratio total chlorophylls to total carotenoids, (a + b)/(x + c), (4.07–4.25) as compared to shade leaves (Chl a/b 2.62–2.72) and (a + b)/(x + c) of 5.18–5.54. Blue-shade and half-shade leaves have an intermediate position between sun and shade leaves in all investigated parameters including the ratio F v/F o (maximum quantum yield of PS2 photochemistry) and are significantly different from sun and shade leaves but could not be differentiated from each other. The mean values of the Chl fluorescence decrease ratio R Fd of blue-shade and half-shade leaves fit well into the strong linear correlation with the net photosynthetic rates P N of sun and shade leaves, thus unequivocally indicating that the determination of the Chl fluorescence decrease ratio R Fd is a fast and indirect measurement of the photosynthetic activity of leaves. The investigations clearly demonstrate that the photosynthetic capacity and pigment composition of leaves and chloroplasts strongly depend on the amounts and quality of light received by the leaves.  相似文献   

18.
We conducted nutritional analyses of diets offered to and ingested by seven pairs of horned guans (Oreophasis derbianus) in three zoos. Digestibility was calculated with individually housed birds (n=1 at each zoo). Diets offered varied widely among institutions, both in ingredients fed as well as in nutrient composition. Feeding selectivity was evident through differences in composition of diets offered vs. consumed, with fruit (bananas, grape, and/or plantain) and avocado (when offered) highly preferred; green leaves, poultry pellets, and other vegetables comprised lesser proportions of the diet. All facilities fed 2–3X more food than consumed, allowing a great degree of choice of preferred items and potentially consumption of nutritionally imbalanced diets—in particular, mineral constituents. Diets were highly digestible; dry matter (DM) digestion coefficients ranged from 70 to ∼90%; protein digestibility varied from 30 to 80%; fat was >90% digestible. Diet composition was compared with known nutritional requirements of domestic avian species, and feeding recommendations discussed. Despite the wide variability in nutrient composition of diets eaten (i.e. protein 6–10% of DM; fat 2–17% of DM), no overt health problems were noted and all pairs had successfully reproduced on these diets. It is suggested that horned guans may have nutrient requirements more similar to those suggested for other frugivorous birds than values determined for poultry as the physiologic model. Comparisons with native food items, as well as more detailed nutrient balance studies, may provide even better guidelines for captive management of this highly endangered species. Zoo Biol 28:319–330, 2009. © 2009 Wiley-Liss, Inc.  相似文献   

19.
This work reports a part of hydroponic experiment results concerning changes in Salix viminalis L. cv. ‘Cannabina’ morphology and physiology under stress conditions with different copper concentration levels and verifies our earlier results about the role of different Ca/Mg ratios in trace elements’ accumulation efficiency. In this part, we present the copper accumulation and changes in willow biomass. Concentration of copper in roots, rods, shoots and leaves was analyzed with flame atomic absorption spectrometry. Selected indices characterizing copper accumulation and plant biomass structure were calculated to estimate the potential of willow to remove metal from polluted solution. Our results indicate a general increase of copper accumulation by selected willow organs with increase of copper concentration in modified Knop’s medium. Moreover, significant differences in copper phytoextraction between plants under different Ca/Mg ratios were affirmed (1:10 > 4:1 > 20:1 > 1:1/4).  相似文献   

20.
In this study, 30 soil samples were collected from 0–5 cm and 15–20 cm depths in the vicinity of the Miduk Porphyry Copper Mine in Kerman Province, southeast Iran. The samples were analyzed for total concentrations of eight potentially toxic elements. The bioavailability of trace elements is determined using sequential extraction analysis. Average concentrations of As, Cd, Cr, Cu, Mo, Ni, Pb, and Zn in soil samples are 26.9, 0.49, 56.31, 201.18, 1.77, 45.6, 83.87, and 191.94 mg kg?1, respectively. Also, to assess the bioaccumulation of the analyzed elements, the roots and the leaves of three plant species were sampled and analyzed. The mobility of the analyzed trace elements shows the following decreasing order: Cd > Mo > Ni > Zn > Cu > Cr >Pb> As. The distribution pattern of elements indicates that elemental concentration in Miduk soils is highly influenced by bedrock composition, while soil pollution is mostly affected by ancient mining.  相似文献   

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