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1.
Seasonal changes in microbial biomass and nutrient flush in forest soils   总被引：14，自引：0，他引：14  
Microbial biomass and N, P, K, and Mg flushes were estimated in spring, summer, autumn, and winter samples of different forest soils. The microbial biomass showed significant seasonal fluctuations with an average distribution of 880±270 g C g-1 soil in spring, 787±356 g C g-1 soil in winter, 589±295 g C g-1 soil in summer, and 560±318 g C g-1 soil in autumn. The average annual concentrations of C, N, P, K, and Ca in the microbial biomass were 704, 106, 82, 69 and 10 g g-1 soil, respectively. Microbial C represented between 0.5 and 2% of the organic soil C whereas the percentage of microbial N with respect to the total soil N was two-to threefold higher than that of C; the annual fluctuations in these percentages followed a similar trend to that of the microbial biomass. Microbial biomass was positively correlated with soil pH, moisture, organic C, and total N. The mean nutrient flush was 31, 15, 7, and 4 g g-1 soil for N, K, P, and Mg, respectively, and except for K, the seasonal distribution was autumn spring winter summer. The average increase in available nutrient due to the mineralization of dead microbial cells was 240% for N, and 30, 26, and 14% for P, K, and Mg, respectively. There was a positive relationship between microbial biomass and the N, P, K, and Mg flushes. All the variables studied were significantly affected by the season, the type of soil, and the interaction between type of soil and season, but soil type often explained most of the variance.  相似文献   

2.
Nine stream sites in the Blackfoot River watershed in southeastern Idaho were sampled in September 2000 for water, surficial sediment, aquatic plants, aquatic invertebrates, and fish. Selenium was measured in these aquatic ecosystem components, and a hazard assessment was performed on the data. Water quality characteristics such as pH, hardness, and specific conductance were relatively uniform among the nine sites examined. Selenium was elevated in water, sediment, aquatic plants, aquatic invertebrates, and fish from several sites suggesting deposition in sediments and food web cycling through plants and invertebrates. Selenium was elevated to concentrations of concern in water at eight sites (>5 g/L), sediment at three sites (>2 g/g), aquatic plants at four sites (>4 g/g), aquatic invertebrates at five sites (>3 g/g), and fish at seven sites (>4 g/g in whole body). The hazard assessment of selenium in the aquatic environment suggested low hazard at Sheep Creek, moderate hazard at Trail Creek, upper Slug Creek, lower Slug Creek, and lower Blackfoot River, and high hazard at Angus Creek, upper East Mill Creek, lower East Mill Creek, and Dry Valley Creek. The results of this study are consistent with results of a previous investigation and indicate that selenium concentrations from the phosphate mining area of southeastern Idaho were sufficiently elevated in several ecosystem components to cause adverse effects to aquatic resources in the Blackfoot River watershed.  相似文献   

3.
Summary We studied the effects of the organophosphorus insecticide methidathion, at concentrations of 10, 50, 100, 200 and 300 g g-1 in an agricultural soil, on fungi, total bacterial populations, aerobic N2-fixing bacteria, denitrifying bacteria, nitrifying bacteria (phases I and II), and nitrogenase activity (acetylene reduction assay). The presence of 10–300 g g-1 of methidathion significantly increased fungal populations (colony-forming units). Denitrifying bacteria, aerobic N2-fixing bacteria and N2 fixation were significantly increased at concentrations of 50–300 g g-1. The total number of bacteria increased significantly at concentrations of 100–300 g g-1. Nitrifying bacteria decreased initially at concentrations of 300 g g-1, but recovered rapidly to levels similar to those in the control soil without the insecticide.  相似文献   

4.
Summary Plants grown from seed with high (1.5–7.3 g Mo seed-1) and low (0.07–1.4 g Mo seed-1) Mo contents were grown in the presence and absence of Mo in growth media (perlite) or in a flowing-solution culture, in a controlled environment. Neither the high (1.5 g Mo seed-1) nor the low (0.1 g Mo seed-1) Mo content in seed from a small-seeded genotype (BAT 1297) was able to prevent Mo deficiency (reduced shoot, root and nodule dry weight, N2 fixation and seed production) in growth media without an external supply of Mo, whereas both the high (7.3 g Mo seed-1) and the low (0.07 g Mo seed-1) contents in seed were able to prevent Mo deficiency in a large-seeded genotype (Canadian Wonder). Responses to Mo treatment by the Two genotypes were inconsistent between the growth media and solution culture experiments. Seed with a large Mo content (3.5 g Mo seed-1) from the Canadian Wonder genotype was unable to prevent Mo deficiency (reduced shoot and nodule dry weight and N2-fixation) in a solution culture without an external source of Mo, whereas both the large (1.7 g Mo seed-1) and the small (0.13 g Mo seed-1) contents in seed prevented a deficiency in BAT 1297. Growing plants from seed with a small Mo content, without additional Mo, reduced the seed Mo content by 83–85% and seed production by up to 38% in both genotypes. Changes in seed size and increases in shoot, root and nodule dry weight occurred, but varied with the genotype and growth conditions. These effects were also observed in some cases where plants were grown with additional Mo, demonstrating that the amount of Mo in the seed sown can influence plant nutrition irrespective of the external Mo supply. Nodule dry weight, total N content of shoots and seed production were improved by using seed with a small Mo content (1.64–3.57 g Mo seed-1) on acid tropical soils in Northern Zambia. Plants of both the large- and small-seeded genotypes grown from seed with a small Mo content (<1.41 g Mo seed-1) had a smaller nodule weight, accumulated less N and produced less seed. The viability of seed with a small Mo content was lower (germination up to 50% less) than that of seed with a large Mo content.  相似文献   

5.
Installation of heating cables for warming soil was used to evaluate the effect of disturbance on soil solution chemistry within a northern hardwood forest (Adirondack Mountains, New York). Differences in response among treatments suggested the importance of both the depth and timing of cable installation. There were increases (p>0.05) in many solutes within pilot study plots in which surrogate cable was installed at 15 cm depth. Most notably, mean nitrate concentrations for the 1st year following disturbance were 744 eq l-1 at 15 cm depth compared to 7 eq l-1 for the non-disturbed control. A comparison of pilot plots with 5 cm cable depth and an unheated soil-warming control plot with the same cable disturbance showed that the seasonality of soil disturbance may have a key role in response to disturbance. The soil solution response was diminished if installation occurred during the spring, a period of rapid uptake of nitrogen by vegetation. Mean nitrate concentrations were 176 eq l-1 for 5-cm pilot plots (installed in fall 1991) versus 6 eq l-1 for 5-cm, unheated soil-warming control plots (installed in spring 1992). Disturbance effects were attenuated over time and not generally apparent 1 year after installation.  相似文献   

6.
Summary A 2-year study (1983–1984 to 1984–1985) was conducted to estimate temporal and seasonal changes and the effects of fertiliser on some soil chemical, biochemical and microbiological characteristics. The soil used was a Typic Vitrandept under grazed pasture. Soil samples were taken regularly to a depth of 75 mm from paired unfertilised and fertilised (500 kg ha– 30% potassic superphosphate) plots. Except for organic C, fertiliser had little or no effect on the characteristics measured. Organic C averaged about 9.2% in unfertilised soil and was about 0.3% higher in the fertilised soil. The size of the microbial biomass fluctuated widely in the 1st year (3000 g C g–1 in February to 1300 g C g–1 in September) but there was less variation in the 2nd year (range 1900 g C g–1 to 2500 g C g–1 soil). CO2 production values (10- to 20-day estimates averaged 600 g of CO2-C g–1 soil) were generally higher in spring compared to the rest of the year. Water extractable C increased over winter and declined through spring in both years (range 50 g C g–1 soil to 150 g C g–1 soil). Mineral-N flush values were higher in summer (300 g N g–1 soil) and lower in winter months (200 g N g–1 soil). The pattern of variation of microbial N values was one of gradual accumulation followed by rapid decline. This rapid decline in values occurred in spring and autumn (range 130–220 g N g–1 soil). N mineralisation and bicarbonate-extractable N showed no clear trend; these values ranged from 100–200 and 122–190 g N g–1 soil, respectively. There was a significant correlation (0.1%) between N mineralisation and bicarbonate-extractable N in the late summer-autumn-early winter period (February–August) in both years but not in spring. These results and their relationships to climatic factors and rates of pasture production are discussed.  相似文献   

7.
The surface ozone (O3) data show an increase by 2.6 % per year during the period 1982–1994 at the rural site of Lithuania. WHO (World Health Organization), UN-ECE (United Nations Economic Commission for Europe), CES (Commission of the European Communities) guideline values for the protection of vegetation from adverse effects are exceeded during the growing season at the Preila coastal station. Ozone exposures for different concentration threshold are estimated during daylight hours in April-September. These values above 60 g/m3 varied between 10 000 and 43 000 (g/m3) ·h, above 80 g/m3 — between 1700 and 15 000 (g/m3) ·h, above 100 g/m3 — between 130 and 3700 (g/m3) ·h during separate years. Maximum hourly ozone values were observed from 116 to 228 g/m3 during this period.  相似文献   

8.
Identification of ergosterol in vesicular-arbuscular mycorrhizae   总被引：1，自引：0，他引：1  
Summary Ergosta-5,7,22-tri-3-enol (ergosterol) was identified by gas chromatography-mass spectrometry in roots of berseem (Trifolium alexandrinum L., cv. Landsorte) and sweet corn (Zea mays L., cv. Honeycomb-F1) infected with the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus intraradices. The fungal-derived compound ergosterol was determined quantitatively in root extracts using reverse-phase high performance liquid chromatography. The concentrations of ergosterol in VAM-infected roots reached 72 g-1 dry material in berseem and 52 g-1 in sweet corn after 80 days of growth, whereas concentrations in non-infected roots remained below 8 g-1 dry weight. Additionally, phytosterols such as -sitosterol, campesterol, and stigmasterol were detected in both infected and non-infected roots. Ergosterol, as a characteristic fungal substance, is proposed as an indicator of fungal biomass in the early stages of VAM infection.  相似文献   

9.
The degree to which floating aquatic plants concentrate Se in tissues was determined for four species grown in solutions containing various levels of Se. Results of this greenhouse study showed that all four plant species, Azolla caroliniana, Eichhornia crassipes, Salvinia rotundi folia, and Lemna minor absorbed Se quickly upon exposure to Se in water as concentrated as 2.5 g Se mL–1, and attained maximum tissue concentrations within 1 to 2 weeks. Azolla absorbed Se to the highest tissue concentration (about 1000 g Se g–1 dry matter) from the 2.5 g Se mL–1 solution, followed by Salvinia (700 g Se g–1), Lemna (500 g Se g–1),and Eichhornia (300 g Se g–1). Plant growth appeared unaffected by solution Se concentrations lower than about 1.25 g mL–1. These results indicate potential for rapid Se movement from water into aquatic food chains, and for use of aquatic plants for Se removal in wastewater treatment systems.  相似文献   

10.
Summary The influence of 28 nitrification inhibitors on denitrification of nitrate in soil was studied by determining the effects of different amounts of each inhibitor on the amounts of nitrate lost and the amounts of nitrite, N2O and N2 produced when soil samples were incubated anaerobically after treatment with nitrate or with nitrate and mannitol. The inhibitors used included nitrapyrin (N-Serve), etridiazole (Dwell), potassium azide, 2-amino-4-chloro-6-methylpyrimidine (AM), sulfathiazole (ST), 4-amino-1,2,4-triazole(ATC),2,4-diamino-6-trichloromethyl-s-triazine (CL-1580), potassium ethylxanthate, guanylthiourea (ASU), 4-nitrobenzotrichloride, 4-mesylbenzotrichloride, sodium thiocarbonate (STC), phenylmercuric acetate (PMA), and dicyandiamide (DCD).Only one of the nitrification inhibitors studied (potassium azide) retarded denitrification when applied at the rate of 10 g g–1 soil, and only two (potassium azide and 2,4-diamino-6-trichloromethyl-s-triazine) inhibited denitrification when applied at the rate of 50 g g–1 soil. The other inhibitors either had no appreciable effect on denitrification, or enhanced denitrification, when applied at the rate of 10 or 50 g g–1 soil, enhancement being most marked with 3-mercapto-1,2,4-triazole. Seven of the inhibitors (potassium azide, sulfathiazole, potassium ethylxanthate, sodium isopropylxanthate, 4-nitrobenzotrichloride, sodium thiocarbonate, and phenylmercuric acetate) retarded denitrification when applied at the rate of 50 g g–1 soil to soil that had been amended with mannitol to promote microbial activity.Reports that nitrapyrin (N-Serve) and etridiazole (Dwell) inhibit denitrification when applied at rates as low as 0.5 g g–1 soil could not be confirmed. No inhibition of denitrification was observed when these compounds were applied at the rate of 10 g g–1 soil, and enhancement of denitrification was observed when they were applied at the rate of 50 or 100 g g–1 soil.  相似文献   

11.
Summary In the present experiment, natural protozoan fauna and other microbial components in water extracts from shortgrass prairie soil were separated on the basis of size by differential filtration (8-, 5-, and 3-m porosities). All extracts contained bacteria and fungi, along with a few very small flagellates (3-m pore size filtrate); flagellates and a few small amoebae (5-m pore size filtrate); and flagellates, small amoebae, and small ciliates (8-m pore size filtrate). All microorganisms, except a few species of flagellates, were present in the centrifuge treatment. Each filtrate was added to sterile soil, and the population of each microbial group was determined after inoculation at intervals up to 80 days (at room temperature). Populations of all added groups decreased on initial addition to soil but then increased during the incubation. By following nitrogen, phosphorus, and CO2 dynamics, we observed impacts of protozoan grazing on bacteria, including mineralization of N from microbial biomass.  相似文献   

12.
Mercury Content of Illinois Soils   总被引：2，自引：0，他引：2  
For a survey of Illinois soils, 101 cores had been collected and analyzed to determine the current and background elemental compositions of Illinois soils. Mercury and other elements were determined in six samples per core, including a surface sample from each core. The mean mercury content in the surface samples was 33 ± 20 g/kg soil, and the background content was 20 ± 9 g/kg. The most probable sources of mercury in these soils were the parent material, and wet and dry deposition of Hg0 and Hg2+ derived from coal-burning power plants, other industrial plants, and medical and municipal waste incinerators. Mercury-bearing sewage sludge or other fertilizers applied to agricultural fields could have been the local sources of mercury. Although the mercury content correlated with organic carbon content or clay content in individual cores, when all the data were considered, there was no strong correlation between mercury and either the organic carbon or the clay-size content.  相似文献   

13.
Zusammenfassung Wachstumskurven vom bakteriellen Pflanzenkrebs (crown gall) an verschiedenen Wirtspflanzen (Pelargonium-Arten,Vicia faba, Bryophyllum daigremontianum) zeigen einen Verlauf, der dem anderer biologischer Wachstumsvorgänge außerordentlich ähnlich ist. In den Kurven verschiedener Sippen kommen genetisch bedingte Einflüsse des Wirtsorganismus auf die Tumorentwicklung zum Ausdruck. Sogar die Partnergewebe von Periklinalchimären können in dieser Beziehung unterschiedlich reagieren. Die Kurven schnell wachsender Tumoren nähern sich einer Grenzkurve, die als die Wachstumskurve voll alterierter Tumoren anzusehen ist. Bei Sippen mit langsam wachsenden Tumoren ist häufig die Anfangsphase gehemmt. Tumoranfälligkeit und Tumorwüchsigkeit sind in der Regel gleichsinnig beeinflußt.Mit dem Aufhören des Streckungswachstums entstehen weniger und kleinere Tumoren (Bryophyllum-Blätter,Vicia). Kinetin macht ältere Blätter vonBryophyllum nicht anfälliger. Die heranwachsenden Brutknospen hemmen die Entwicklung von Tumoren an den Blättern. Dekapitieren der Pflanzen fördert dagegen die Tumoren und überdeckt den Hemmungseffekt der Brutknospen. Diese und andere Versuche zeigen, daß pflanzliche Tumoren während der Induktionsphase und in geringerem Ausmaß auch noch später durch physiologische Mechanismen beeinflußbar sind.
Summary Growth diagrams of crown gall tumors on different host plants (species ofPelargonium, Vicia faba, Bryophyllum daigremontianum) are very similar to those of other biological growth processes. Curves of different taxa reveal that development of tumors is influenced by the genetic constitution of host organism. Even partner-tissues of periclinal chimerae may react differently. Curves of rapidly growing tumors approach a limit which should be regarded as growth curve of fully alterated tumors. The initial phase of slowly growing tumors is often retarded. Sensitiveness to tumors and growth of tumors usually are influenced simultaneously.With the end of leaf growth fewer and smaller tumors arise (Bryophyllum-leaves,Vicia). Kinetin does not increase sensitivity to tumors in older leaves ofBryophyllum. Growing adventitious leaf-buds retard tumor development in leaves. Decapitating of plants favours tumors and covers the retarding effect of leaf buds. These and other experiments show that plant tumors may be influenced by physiological mechanisms during the inductive phase, and, though to a lesser extent, also later on.
(crown gall) (Pelargonium, Vicia faba, Bryophyllum daigremontianum) , . , . . , «» . . , , . ( , ). . . , , . , « », , .
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14.
Summary Recent exploration work resulted in interesting new information for the checklist of Korean cultivated plants (Baik et al. 1986). 30 species could be additionally included. For another 36 species collections and/or observations are presented for the first time.
Ergänzende Notizen zur Liste der koreanischen Kulturpflanzen (1)
Zusammenfassung Im Ergebnis der weiteren Exploration konnten interessante neue Informationen für die Liste der koreanischen Kulturpflanzen (Baik et al. 1986) gewonnen werden. 30 Arten wurden neu aufgenommen. Für weitere 36 Arten liegen erstmals Sammlungen und/oder Beobachtungen vor.
(I)
(Baik et al. 1986). 30 . 36 / .
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15.
Zusammenfassung Die Genbank in Gatersleben verfügt über eine umfangreiche Wildroggen-Kollektion, die für die Aufgaben der Züchtungsforschung und Züchtung zur Verfügung steht. Probleme der Erhaltung dieser Kollektion in der Genbank werden diskutiert. In diesem Zusammenhang wird das Reproduktionssystem besonders untersucht.Zur Dokumentation des Materials ist seine Identifikation notwendig. Daher wurde die GattungSecale revidiert. Neukombinationen werden fürS. strictum (Presl) Presl — subsp.kuprijanovii (Grossh.) Hammer, subsp.anatolicum (Boiss.) Hammer, subsp.ciliatoglume (Boiss.) Hammer, subsp.africanum (Stapf) Hammer — und fürS. cereale L. — subsp.afghanicum (Vav.) Hammer — vorgeschlagen. Zur Determination der Sippen wird ein Bestimmungsschlüssel publiziert.Entwicklungstendenzen innerhalb der Gattung werden aufgezeigt.
Preliminary work on monographs of wild plant collections:Secale L
Summary The Gatersleben gene bank holds a large collection of wild rye available for the tasks of breeding research and plant breeding. Problems of maintaining this collection in the gene bank are discussed. In this connection the breeding system is especially studied.A proper identification of the material is a necessary prerequisite for its documentation. Therefore, the genusSecale was revised. New combinations are proposed forS. strictum (Presl) Presl — subsp.kuprijanovii (Grossh.) Hammer, subsp.anatolicum (Boiss.) Hammer, subsp.ciliatoglume (Boiss.) Hammer, subsp.africanum (Stapf) Hammer — and forS. cereale L. — subsp.afghanicum (Vav.) Hammer. Keys for the determination of species and subspecies are given.Evolutionary trends within the genus are demonstrated.
: Secale L
, . . . . Secale. . S. strictum (Presl) Presl — subsp.kuprijanovii (Grossh.) Hammer, subsp.anatolicum (Boiss.) Hammer, subsp.ciliatoglume (Boiss.) Hammer, subsp.africanum (Stapf) Hammer — S. cereale L. — subsp.afghanicum (Vav.) Hammer. . .

Herrn Prof. Dr. Dr. h. c. mult.H. Stubbe aus Anlaß der 85. Wiederkehr seines Geburtstages gewidmet.

Der Beitrag von E. S. entstand im Ergebnis eines Studienaufenthaltes zur Vorbereitung ihrer Dissertation 1986 in Gatersleben.  相似文献   

16.
Zusammenfassung In Fortsetzung früherer Untersuchungen wurden weitere 104 Pflanzenarten aus 24 Familien der einheimischen Flora und des Gaterslebener Sortiments nach einem Standardverfahren orientierend auf vorkommende Alkaloide, Saponine, Sterine und weitere Triterpenoide geprüft.
Summary In continuation of earlier described investigations 104 further plant species from 24 families of the indigenous flora and of the sortiment in Gatersleben have been studied preliminarily for occurring alkaloids, saponins, sterols and other triterpenoids using a standard procedure.
am ¶rt;au . 104 24 «», «», «» «».

I. Mitteilung: Aurich und Mitarb. (1965).  相似文献   

17.
The Shenandoah National Park: Fish in Sensitive Habitats (SNP:FISH) project is a response to declining pH and acid neutralizing capacity in Shenandoah National Park (SNP) streams. SNP receives more atmospheric sulfate than any other USA national park, and pH had decreased to the point where early negative effects on fish were expected. SNP provides the opportunity to study the early stages of acidification effects on fish. Three different classes of geological formations yield streams with low-ANC (0 Eq/L), intermediate-ANC (60–100 Eq/L) or high-ANC (150–200 Eq/L) waters in SNP. This allows a comparison of responses across a water quality gradient in a small geographic area receiving similar deposition. Both chronic and episodic acidification occur in SNP streams. Biological effects are apparent in fish species richness, population density, condition factor, age, size, and bioassay survival. A primary project objective was to provide the necessary data for development and testing models for forecasting changes in fish communities resulting from changes in stream chemistry. Monitored variables include several which are predictive of acidification effects on SNP fish communities.  相似文献   

18.
Zusammenfassung Die Messung von Absorptionsspektren biologischer Objekte in vivo ermöglicht eine rasche Information über die Zusammensetzung und den Zustand der enthaltenen Pigmente, insbesondere bei der Untersuchung photosynthetisch aktiver Organe. Es wird deshalb eine Übersicht über Probleme, Methoden und Anwendungsmöglichkeiten gegeben.Meßtechnische Schwierigkeiten ergeben sich in erster Linie aus der Lichtstreuung, die in verschiedener Weise zu einer Verzerrung der Spektren führt. Eine Verringerung dieser Effekte ist mit verschiedenen Methoden möglich, die entweder das Streulicht oder einen repräsentativen Anteil desselben sammeln oder durch Angleichung des Brechungsindex des umgebenden Mediums die Streuung selbst herabsetzen.Das Auftreten verschiedener Pigmentformen mit ähnlichen spektralen Eigenschaften führt zu einer starken Überlagerung und damit schlechter Auflösung ihrer Absorptionsbanden. Eine Erhöhung der Auflösung ist mit Methoden möglich, die die Halbwertsbreite der Banden verringern. Dazu dienen die Messung bei der Temperatur des flüssigen Stickstoffs (–196 °C) und die Anwendung mathematischer Verfahren zur Bandenverschärfung, insbesondere der Derivativ-Spektrophotometrie.Einige Anwendungsbeispiele demonstrieren den Nutzen der Methode bei der Untersuchung der Chlorophylle in vivo.
Measurement of absorption spectra in vivo
Summary The measurement of absorption spectra of biological objects enables fast information about composition and state of pigments, especially in the study of photosynthetically active organs. Therefore a review is given about problems, methods, and possible applications.Difficulties in the measurement result mainly from light scattering, causing a distortion of spectra in different ways. A reduction of these effects is possible by several methods, which either collect the scattered radiation (or a representative portion of it) or decrease the scattering by adjusting the refractive index of the surrounding medium to those of the cell walls.The existence of different pigment forms having similar spectral properties results in a strong overlapping and bad resolution of their absorption bands. A resolution enhancement is possible by methods reducing the halfwidth of the bands. This can be performed by measurement at liquid nitrogen temperature (–196 °C) and by mathematical methods of band sharpening, especially derivative spectrophotometry.Some examples demonstrate the use of the method in the study of chlorophylls in vivo.
in vivo
in vivo , . , . , , , . , ( ) , , . , , . . (– 196 °C) , — . in vivo.

Herrn Prof. Drs. Dr. h. c.Hans Stubbe zum 75. Geburtstag gewidmet.  相似文献   

19.
Zusammenfassung Bei der Anwendung einer neuen Methodik konnte gezeigt werden (abweichend von den Ergebnissen des Autors von 1968), daß eine Tendenz zu negativem Zusammenhang zwischen Heterosisindex in F1 und Leistungsabfall-index in F2 für die Merkmale Pflanzenhöhe (PH), Grünmasse (PG) und Kornertrag (KrG) bei Mais besteht; dieser Zusammenhang ist aber sehr locker und zeigte signifikante Werte nur unter ungünstigeren Jahresbedingungen.Ferner wurde ein Versuch unternommen, die genotypischen Varianzkomponenten der Heterosis und des Abfalls bei den genannten Merkmalen zu schätzen. Für die Merkmale, die stärker zu Heterosis neigen (PG und KrG) war diese Heritabilität für Abfall überhaupt nicht signifikant, während sie für Heterosis gut gesicherte Werte von etwa 40% ergab.
On some problems referring to heterosis and the reduction in vigour of yield characters in maize
Summary Using a new method it could be demonstrated, in difference to the author's results published in 1968, that there is a tendency to negative correlation between the index of heterosis in F1 and the index of reduction in vigour in F2 for the characters plant height (PH), green matter (PG), and grain yield (KrG) of maize. This mutual relation, however, is rather weak and proved significant only under conditions of unfavourable years.Also an attempt was made to estimate for the above-mentioned characters the genotypic components of variance of both heterosis and reduction in vigour. As to the characters which tend to more strongly marked heterosis (PG and KrG), this heritability was not at all significant for reduction in vigour, but gave sufficiently significant values of about 40% for heterosis.
F1 F2
1968 ., , , F1 F2 . (PH), (PG) (KrG) , , . , , (PG KrG), «» , 40%.
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20.
Zusammenfassung Von den Faktoren, die zur Winterfestigkeit der Gersten beitragen, wird die Frostresistenz untersucht. Dazu wird ein Verfahren des künstlichen Gefrierens im Kältegewächshaus ausführlich beschrieben.Mit Hilfe dieses Verfahrens wurden aus dem Material des Gaterslebener Wintergerstensortiments bisher 367 Zucht- und Landsorten untersucht. Nach Vergleich mit fünf aus früheren Untersuchungen zur Verfügung stehenden Standardsorten ließen sich diese Sorten in entsprechende Resistenzgruppen einordnen. Die Sorten mit guter Frostresistenz sind Albert (Frankreich), Almerfelder, Dominator, Hellmann und Teilhaber, Schwarze Wintergerste (Deutschland), Kostek, Kujawiak, lski II (Polen), Mozdokskij Mestnij, Odesskij 17 (Sowjetunion) und eine Herkunft vom Peloponnes. Der Verlauf ihrer Frostresistenz während des Winters wird im einzelnen charakterisiert. Die 103 Sorten mit mittlerer Frostresistenz sind einzeln aufgeführt (Tabelle 4).Die Möglichkeiten dieses Verfahrens für eine umfassende Beurteilung der Frostresistenz werden diskutiert, ebenso das Problem der Züchtung winterfesterer Gersten.
Summary The frost-hardiness of barley, one of the several factors causing winter-hardiness, has been studied by artificial freezing in a cooled greenhouse. The method is described in detail.Out of the Gatersleben collection 367 varieties and land-races of winter barley were tested. This material was grouped, in comparison to standard varieties, into corresponding classes of frost-resistance according to the degree of plant injury. Varieties with high frost-resistance are Albert (France), Almerfelder, Dominator, Hellmann und Teilhaber, Schwarze Wintergerste (Germany), Kostek, Kujawiak, lski II (Poland), Mozdokskij Mestnij, Odesskij 17 (Sowjet-Union) and one land-race from Peloponnesus. Their reaction to frost-resistance during the winter is described in detail. Further 103 varieties, listed in table 4, showed moderate resistance.Finally the possibilities are discussed, given by this method for a comprehensive estimation of frost-resistance, as well as the problem of breeding winter barley varieties with higher frost resistance.
am ¶rt;au , . . . (qs. . 269). 367 . (qg II) : (), , , , (), , , ·. II (), , 17 () . . 103 ( II/III, III III/IV) . 4. , ¶rt; , ¶rt; .
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