Quick screening of cowpea (Vigna unguiculata) genotypes for aluminium tolerance in an aluminium-treated acid soil     

W. J. Horst 《植物养料与土壤学杂志》1985,148(3):335-348

In greenhouse experiments with small pots, seeds of cowpea (Vigna unguiculata) were planted into an acid soil (Oxic Paleudult from Onne, South-East Nigeria) which had been treated with Al₂(SO₄)₃-Cowpea genotypes showed varying seedling growth inhibition within 7 days when grown in soil containing 2.2 meq Al/100 g soil. Soil and plant analysis confirmed, that Al toxicity, and consequently differences in Al tolerance, were responsible for the genotypically different seedling growth responses. 783 genotypes showed a wide range of Al tolerance when screened using this technique. In a long-term pot experiment the effect of Al application to the soil on seed yields of 9 genotypes was studied. Although no significant correlation could be found between depression by Al of seedling growth and grain yield of the genotypes, the same genotypes were classified as most tolerant and most sensitive in both cases. The results show that the simple and quick screening method using Al-treated soil allows the identification of genotypes adapted to soils with high Al supply.  相似文献   

A comparison of methods for soil microbial population and biomass studies     

K. H. Domsch  T. H. Beck  J. P. E. Anderson  B. Sderstrm  D. Parkinson  G. Trolldenier 《植物养料与土壤学杂志》1979,142(3):520-533

A comparison was made of 15 different techniques which are used in assessing soil microbial populations and/or biomasses. These include direct observations (fungal standing crop, fluorescein diacetate active mycelia, acridine orange stained bacteria), cultural methods (bacterial plate counts), physiological methods (total microbial, bacterial and fungal biomasses, O₂-uptake), soil enzyme analyses (dehydrogenase, catalase, alkaline and acid phosphatase, protease, amylase), and ATP-analyses. The various techniques were applied to six soils known to have different microbial characteristics. The results are discussed with respect to the convertability of counts and measurements into microbial biomasses, the variability of the techniques, the correlations within comparable groups of methods, and the practical limitations in application of individual methods to different soils.  相似文献   

Wechselwirkungen zwischen Boden-Huminstoffen und Metall-Ionen I. Isolierung und Charakterisierung der Boden-Huminstoffe     

Wilfried Finger  Bernhard Post  Horst Klamberg 《植物养料与土壤学杂志》1990,153(5):305-312

Interactions between soil humic substances and metal ions I. Isolation and characterization of the soil humic substances From two horizons of a podzol humic acids and fulvic acids were isolated by two different methods. The obtained samples were characterized by elemental analysis, the determination of the ash and moisture content, functional group analysis as well as FTIR-, ¹H-NMR-, and ¹³C-NMR-spectroscopic examinations. In spite of the different isolation methods humic and fulvic acids show great similarities. A higher oxidized state and a lower content of aromatic structural features are clearly observed in the fulvic acids in contrast to humic acids. Besides aromatic structural elements, distinct aliphatic sections were detected in the investigated samples, which showed a lower concentration in the less transformed fractions of the Ahe-horizon.  相似文献   

Genotypic differences in uptake and translocation of cadmium in bean and maize inbred lines     

Yanliang Guo  Horst Marschner 《植物养料与土壤学杂志》1996,159(1):55-60

For better understanding of mechanisms responsible for genotypic differences in uptake and translocation of cadmium (Cd) in different plant species, two maize (Zea mays L.) inbred lines (B37 and F2) and a bean (Phaseolus vulgaris L.) cultivar (Saxa) were grown in a complete nutrient solution with additional 0.5 μM Cd and 250 μM buthionine sulfoximine (BSO), an inhibitor of PC synthesis, alone or in combination. The maize line B37 had a much higher Cd content in shoots (116.2 mg Cd kg^?1 dry wt.) than F2 (32.7 mg Cd kg^?1 dry wt.) and bean (1.83 in leaves, and 2.85 mg Cd kg^?1 dry wt. in stems), whereas in roots the Cd content was much higher in bean (602.6 mg Cd kg^?1 dry wt.) than in maize (427.1 mg Cd kg^?1 dry wt. in B37, and 428.2 mg Cd kg^?1 dry wt. in F2). Application of BSO markedly decreased Cd contents in roots of bean and maize lines, and also Cd contents in shoots and stem basis of both maize lines, while Cd contents in leaves, stems and stem basis of bean were not reduced by BSO. In root extracts (Tris-HCl buffer, pH 8.0) the proportion of Cd in the soluble fraction was much lower in bean (29.6%) than in the maize lines B37 (58.6%) and F2 (60.1%). Compared with the whole root tissue, Cd contents in the stele of the roots were much lower, especially in bean, and decreased by BSO in both maize lines, but not in bean. Gel-chromatography of root extracts strongly suggested that in the soluble fraction about 80% of the Cd was present as Cd-phytochelatin (PC) complexes in B37, whereas in F2 this Cd fraction accounted for about 50%, and in bean only for a few percent in the soluble fraction, Our results suggest that Cd-PC complexes constitute a mobile form in plants. The lower proportion of Cd in the soluble fraction as well as lower PC production in roots of bean compared to maize lines may be the main reasons for the very low Cd translocation from roots to shoots in bean plants.  相似文献   

Long-term nitrogen balance for pearl millet (Pennisetum glaucum L.) in an acid sandy soil of Niger     

Hermann Hafner  Joachim Bley  Andr Bationo  Peter Martin  Horst Marschner 《植物养料与土壤学杂志》1993,156(2):169-176

On acid sandy soils of Niger (West Africa) fertilizer N recovery by pearl millet (Pennisetum glaucum L.) is often more than 100 per cent in years with normal or above average rainfall. Biological nitrogen fixation (BNF) by N₂-fixing bacteria may contribute to the N supply in pearl millet cropping systems. For a long-term field experiment comprising treatments with and without mineral fertilizer (F) and with and without crop residue application (CR) a N balance sheet was calculated over a period of six years (1983-1988). After six years of successive millet cropping total N uptake (36-77 kg N ha^?1 yr^?1) was distinctly higher than the amount of fertilizer N applied (30 kg N ha^?1 yr^?1). The atmospheric input of NH₄-N and NO₃-N in the rainwater was about 2 kg N ha_?1 yr^?1, 70 % in the form of NH₄-N. Gaseous NH₃ losses from urea (broadcast, incorporated) were estimated from other experiments to amount to 36 % of the fertilizer N applied. Nitrogen losses by leaching (15 to > 25 kg N ha^?1 yr^?1) were dependent on the treatment and on the quantity and distribution of single rainfall events (>50 mm). Decline in total soil N content (0-60 cm) ranged from 15 to 48 kg N ha^?1 yr^?1. The long-term N balance (1983-1988) indicated an annual net gain between 6 (+CR-F) and 13 (+CR+F) kg N ha^?1 yr^?1. For the control (-CR-F) the long-term N balance was negative (10 kg N ha^?1 yr^?1). In the treatment with crop residues only, the N balance was mainly determined by leaching losses, whereas in treatments with mineral fertilizer application the N balance depended primarily on N removal by the millet crop. The annual net gain in the N balance increased from 7 kg ha^?1 with mineral fertilizer to 13 kg ha^?1 in the combination mineral fertilizer plus crop residues. In both the rhizosphere and the bulk soil (0-15 cm), between 9 and 45% of the total bacterial population were N₂-fixing (diazotrophic) bacteria. The increased N gain upon crop residue application was positively correlated with an increase in the number of diazotrophic and total bacteria. The data on bacterial numbers suggest that the gain of N in the longterm N balance is most likely due to an N input by biological nitrogen fixation. In addition, evidence exists from related studies that the proliferation of diazotrophs and total bacteria in the rhizosphere due to crop residue application stimulated root growth of pearl millet, and thus improved the phosphorus (P) acquisition in the P deficient soil.  相似文献   

Root growth of maize cultivars under field conditions as studied by the core and minirhizotron method and relationships to shoot growth     

Franz Wiesler  Walter J. Horst 《植物养料与土壤学杂志》1994,157(5):351-358

  相似文献   

Wechselwirkungen zwischen Boden-Huminstoffen und Metall-Ionen II. Untersuchung von Boden-Huminstoffen mit der Gel-Permeations-Chromatographie und der Dampfdruck-Osmometrie     

Wilfried Finger  Bernhard Post  Horst Klamberg 《植物养料与土壤学杂志》1991,154(4):287-291

Interaction between soil humic substances and metal ions. II. Investigation of soil humic substances by gel permeation chromatography and vapour pressure osmometry By gel permeation chromatography and vapour pressure osmometry average molar masses of soil fulvic and soil humic acids from two horizons of a podzol were determined. For the fulvic acids average molar masses of 9000 g/mol were obtained by the chromatographic method, while 5000 g/mol were obtained by the osmometric method. In contrast to these results for the humic acids values were measured which are 3 - 4 times larger when measured by gel permeation chromatography and 2 - 3 times smaller when measured by vapour pressure osmometry. The average molar masses found show that the applied methods of isolation and purification as well as the different determination methods with the experimental conditions attached to them have a considerable influence on the molecular size of the isolated humic substances.  相似文献   

Soil nutrient supply and biomass production in a mixed forest on a skeleton‐rich soil and an adjacent beech forest     

Dirk Hlscher  Dietrich Hertel  Horst Koenies 《植物养料与土壤学杂志》2002,165(6):668-674

In the natural forest communities of Central Europe, beech (Fagus sylvatica L.) predominates in the tree layer over a wide range of soil conditions. An exception with respect to the dominance of beech are skeleton‐rich soils such as screes where up to 10 broad‐leaved trees co‐exist. In such a Tilia‐Fagus‐Fraxinus‐Acer‐Ulmus forest and an adjacent mono‐specific beech forest we compared (1) soil nutrient pools and net nitrogen mineralization rates, (2) leaf nutrient levels, and (3) leaf litter production and stem increment rates in order to evaluate the relationship between soil conditions and tree species composition. In the mixed forest only a small quantity of fine earth was present (35 g l^—1) which was distributed in patches between basalt stones; whereas a significantly higher (P < 0.05) soil quantity (182 g l^—1) was found in the beech forest. In the soil patches of the mixed forest C and N concentrations and also concentrations of exchangeable nutrients (K, Ca, Mg) were significantly higher than in the beech forest. Net N mineralization rates on soil dry weight basis in the mixed forest exceeded those in the beech forest by a factor of 2.6. Due to differences in fine earth and stone contents, the volume related soil K pool and the N mineralization rate were lower in the mixed forest (52 kg N ha^—1 yr^—1, 0—10 cm depth) than in the beech forest (105 kg N ha^—1 yr^—1). The leaf N and K concentrations of the beech trees did not differ significantly between the stands, which suggests that plant nutrition was not impaired. In the mixed forest leaf litter fall (11 %) and the increment rate of stem basal area (52 %) were lower than in the beech forest. Thus, compared with the adjacent beech forest, the mixed forest stand was characterized by a low volume of patchy distributed nutrient‐rich soil, a lower volume related K pool and N mineralization rate, and low rates of stem increment. Together with other factors such as water availability these patterns may contribute to an explanation of the diverse tree species composition on Central European screes.  相似文献   

Differences between wheat cultivars in acquisition and utilization of phosphorus     

Walter J. Horst  Mohamed Abdou  Franz Wiesler 《植物养料与土壤学杂志》1996,159(2):155-161

In an attempt to evaluate whether breeding and selection for high yielding capacity changed the P requirement of modem wheat cultivars. the response of two wheat cultivars to different levels of P supply was investigated. A traditional cultivar (‘Peragis’) and a modern spring-wheat cultivar (‘Cosir’) were cultivated in a C-loess low in available P and high in CaCO₃ in 120 cm high PVC tubes. In addition and for comparison, nutrient solution experiments were also conducted. Shoot growth, root growth. P uptake. P translocation and P distribution within the shoot at different developmental stages were compared. The grain yield of the modern cultivar ‘Cosir’ was higher at limiting and non-limiting P supply and. therefore, this cultivar can be considered as more P-efficient than the traditional cultivar. Grain yield reduction at low P supply was mainly due to an inhibition of tillering and thus lower number of ears per plant, whereas the number of grains per ear was hardly affected. Reduced tillering at low P supply could not be related to P concentrations in the shoot meristematic tissues which were generally much higher than in other plant tissues and kept at an elevated level even at limiting P supply. Root branching (1^st order laterals) was reduced at limiting P supply in ‘Cosir’ but not in ‘Peragis’ which, generally, had lower numbers of laterals at the beginning of tillering. From the results it can be concluded that the main factors contributing to the higher P efficiency of the modern cultivar ‘Cosir’ are (i) efficient use of assimilates for root-growth characteristics which enhance P acquisition: enhanced root branching and thus smaller mean root diameter and longer root hairs, (ii) an efficient P uptake system, (iii) efficient remobilization of P from vegetative plant organs to the grains, and most importantly (iv) lower P requirement for grain yield formation because of lower ear number per plant but higher grain number per ear.  相似文献   

Deep Impact observations by OSIRIS onboard the Rosetta spacecraft   总被引：1，自引：0，他引：1  

Keller HU  Jorda L  Küppers M  Gutierrez PJ  Hviid SF  Knollenberg J  Lara LM  Sierks H  Barbieri C  Lamy P  Rickman H  Rodrigo R 《Science (New York, N.Y.)》2005,310(5746):281-283

The OSIRIS cameras (optical, spectroscopic, and infrared remote imaging system) onboard the European Space Agency's Rosetta spacecraft observed comet 9P/Tempel 1 for 17 days continuously around the time of NASA's Deep Impact mission. The cyanide-to-water production ratio was slightly enhanced in the impact cloud, compared with that of normal comet activity. Dust particles were flowing outward in the coma at >160 meters per second, accelerated by the gas. The slope of the brightness increase showed a dip about 200 seconds after the impact. Dust Afrho values before and long after the impact confirm the slight decrease of cometary activity. The dust-to-water mass ratio was much larger than 1.  相似文献