Application of random amplified polymorphic DNA markers to evaluate intraspecific genetic variation in the Elymus alaskanus complex (Poaceae)

Random amplified polymorphic DNA (RAPD) markers were used to evaluatethe levels and patterns of genetic diversity in ten Elymusalaskanus populations, which were collected from Canada, USA,Greenland and Russia. Ten arbitrarily chosen decamer primers were used in thisstudy. The results revealed high levels of variation. The mean number of allelesper locus (Ap) was 1.5, ranging from 1.4 to 1.6, the meanpercent of polymorphic loci (Pp) was 49.5%, ranging from35.1% to 64.9%, and the mean gene diversity (Hep) was0.162, varying from 0.142 to 0.262. The total variation wasH _T = 0.403. When partitioned(G _ST), 60% of the total variation was foundamong the populations. Although the genetic diversity values obtained with RAPDsare much higher than for allozymes, they are similar regarding how the geneticvariation is distributed among populations. In addition, a similar geneticpattern of population differentiation, where populations from Greenland andthe USA (violaceus and latiglumis)were clearly separated from the others (hyperarcticus,komarovii and sajanensis), wasrevealed by both the cluster and principal coordinates analyses.     

Communities of Enchytraeidae (Oligochaeta) in planted birch stands as compared with natural forests in central Finland

This study compares the enchytraeid communities in anthropogenous birch (Betula pendula) stands of different origin with each other and with natural forests at the same latitude in Finland. Nine sites were investigated: three birch stands planted ca. 30 years prior to the study after clear-cutting of spruce stands, three birch stands established ca. 30 years earlier on arable soil (cleared from earlier coniferous forest), and three natural deciduous forests. Each site was sampled three times (May, August and October) in 1999, animals were extracted using the wet funnel method, counted and identified. Non-metric multidimensional scaling (NMS) was used to analyse the communities. There were clear differences between the birch stands established after spruce forest and after cultivation, and between these and natural deciduous stands, but even more between replicates of similarly managed forests. Total numbers and populations of most species were lower in birch-after-field than in birch-after-spruce. The superdominant species in coniferous forests, Cognettia sphagnetorum, was dominant in all birch-after-spruce sites and one natural deciduous site. Enchytronia parva was the only species more abundant in birch-after-field than in birch-after-spruce. It is hypothesized that, in addition to soil acidity, accidental transport by man explains the presence of many species on a given locality, and that competition with earthworms plays a role in regulating enchytraeid abundances.     

Seasonal differentiation of soil mesofauna in a littoral dune of the Egyptian Mediterranean coast

Summary Soil mesofauna (sensu Ghilarov, i.e., larger than 1 mm) was sampled from under four shrub species (Lygos raetam, Thymelaea hirsuta, Lycium shawii, and Josonia candicans) growing on the littoral oolitic sand dunes at Gharbaniat, 53 km W of Alexandria, Egypt, for a period of more than 30 months, spanning 3 years. Population density (PD) was calculated in relation to area of shrub canopy. Seasons were considered, according to the prevailing climatic conditions as well as to earlier physiological studies on the animals concerned, as: four winter months, four summer months and two months for each of the transitional seasons spring and autumn. The PD values obtained for each season thus defined were combined for the 41 taxa that were sampled. The table of these data was treated by correspondence analysis (CA) and ascending hierarchic classification (AHC), by the Roux DATA-VISION programme (suitable for Apple). Results from such treatment show that fauna as related to shrub species are differentiated along the first factorial axis, while as related to seasons they are differentiated along the second axis. Taxa common to all shrubs and to all seasons are centrally placed and cause some confusion in the resolution. Summer taxa are more distantly placed than those related to the other three seasons. Fauna under Lygos is richer, more diverse, and more complementary as regards trophic levels (with predators), and could probably be the source for replenishing the fauna of the other shrubs at all seasons. The AHC method did not show a similarly clear differentiation.Dedicated to the late Prof. Dr. M.S. Ghilarov     

Multivariate analysis approach to evaluate a germplasm collection of Hedysarum coronarium L.

Autochthonous germplasm collected in Spain (Ca´diz and Baleares provinces), Italian ecotypes and cultivated material supplied by a commercial firm were analysed by using a multivariate approach applied to a set of morphological traits. According to these analyses the cultivated material could clearly be separated from the autochthonous germplasm. Variation was observed among the traits studied; Principal Stem Diameter, Leaf Area at Flowering and Susceptibility to Oidium were the main traits in grouping and separating sulla (Hedysarum coronarium L.) entries. A new ecotype (Tarifa) could be used in plant breeding as being a source of resistance to Oidium. The multivariate approach appears to be a valid system for germplasm evaluation in sulla with a higher discriminant capacity than multiple single trait analysis.     

Capacity of various organic residues to support adequate earthworm biomass for vermicomposting

Summary We tested the potential of different kinds and combinations of wastes to support the biomass ofEisenia fetida (Sav.) capable of processing a given amount of waste in a period of ca. 1 month. Mixed miscellaneous wastes and activated sewage sludge mixed with or embedded in sieved pine bark showed capacity to maintain the required biomass for a long period. Wastes were converted into odourless castings of good physical structure, provided that a sufficient population was present from the beginning and fresh waste was added regularly. A horizontally working worm bed compost was designed instead of the load-on-top principle.     

Die Gaterslebener Mutanten der Saatgerste in Beziehung zur Formenmannigfaltigkeit der ArtHordeum vulgare L. s. l. I

Zusammenfassung Es werden 75 röntgeninduzierte Mutanten der Sommergerstensorten Donaria und Haisa morphologisch beschrieben. Sie werden unter der Rangstufe Linie (auf dem gleichen Rang wie die Sorte), zusammengefaßt nach Hauptmerkmalen, in das morphologische System eingeordnet. 71 dieser Mutantenlinien konnten 17 verschiedenen Varietäten (4 Convarietäten) zugeordnet werden. Zwei dieser Varietäten (var.calcaratum, p. 144; var.heteroglumatum p. 152) stellen neue Merkmalskombinationen dar und werden beschrieben. Bei den restlichen 4 Mutantenlinien stieß die Einordnung auf Schwierigkeiten, ihre Stellung bleibt vorläufig offen.     

Genetic resources for improving nitrogen fixation in legume-rhizobia symbiosis

Leguminous crops are genetically polymorphous for the balance between symbiotrophic and combined types of nitrogen nutrition. In pea, polebean, alfalfa and fenugreek the wild-growing populations and local varieties exceed the agronomically advanced cultivars in the activity of N₂ fixation that occurs in symbiosis with nodule bacteria (rhizobia). Combined nitrogen nutrition ensures higher productivity than symbiotrophic one in the old leguminous crops (pea, alfalfa, common vetch, polebean, soybean), while the symbiotrophic type dominates in some young crops (hairy vetch, kura clover, goat's rue). An importance is emphasized of using the symbiotically active wild-growing genotypes as the initial material for breeding the legume cultivars. The data on high heritability (broad sense, narrow sense, realized) of the legume symbiotic activity demonstrate that the plant selection for this activity may be highly effective. A range of methods to select the legumes for an improved symbiotic activity is available including plant growth in N-depleted substrates, analysis of nodulation scores, direct (isotopic) and indirect (acetylene reduction) estimation of nitrogenase activity. Analysis of the specificity of interactions between different plant genotypes and bacterial strains (via two-factor analysis of variance) demonstrates the strain-specific plant polygenes are of a special importance in controlling the intensity of nitrogen fixation. Therefore, a coordinated plant-bacteria breeding is required to create the optimal combinations of partners' genotypes. Selection and genetic construction of the commercially attractive rhizobia strains should involve improvement of nitrogen fixing, nodulation and competitive abilities expressed in combination with the symbiotically active plant genotypes, Breeding of the leguminous crops for the preferential nodulation by highly active rhizobia strains, for the ability to support N₂ fixation under moderate N fertilization levels and to ensure a sufficient energy supply of symbiotrophic nitrogen nutrition is required     

Seed protein diversity in Solanum melongena L. and its wild and weedy relatives

Seed protein profiles by SDS-PAGE were studied in 72 accessions ofSolanum melongena L. and its related taxa in subgenusLeptostemonum (Dunal) Bitter. Comparisons based onJaccard's similarity and UPGMA clustering revealed interrelationships broadly inconformity with the conventional taxonomic treatments. Thus,S. viarum Dunal (sectionAcanthophora Dunal), S.torvum Swartz (section Torva Nees) andS. sisymbriifolium Lam. (sectionCryptocarpum Dunal) were located on separate branches ofthe dendrogram while all taxa of section Melongena Dunal,except S. macrocarpon Dunal, wereclustered closer together. S.melongena, incanum and insanum,all members of the eggplant complex, were revealed to bear very high similaritywith each other. Most of their accessions had identical band patterns supportingthe contention that these represent an interbreeding complex with limitedgenetic differentiation.     

Activity,origins and location of cellulases in a silt loam soil

Summary Cellulase activity in a silt loam soil was assayed and characterised using a microcrystalline cellulose substrate (Avicel). Activity was maximal between pH 5.3 and pH 6.0. A 64% loss in activity was observed on air-drying the soil. However, the residual activity was stable to storage at 40°C for 7 days and was resistant to the action of added protease. The component endoglucanase and -D-glucosidase activities in field-moist and air-dried soil were also assayed. The proportion of the soil microbial population able to utilise cellulose was investigated and the persistence of two free (soluble) cellulase preparations of microbial origin was determined following their addition to soil. A rapid decline in the endoglucanase activity of a Streptomyces sp. cellulase preparation was observed while 30% of the original activity of a Trichoderma viride cellulase preparation could still be detected after 20 days. From the data obtained in this study it appears that the major portion of the -D-glucosidase activity is bound to and protected by the soil colloids. By contrast, the major portion of the exo- and endoglucanase activity appears to be free in the soil solution, attached to the outer surfaces of cellulolytic microorganisms or associated in enzyme substrate complexes. The low residual activity measured in air-dried soil may owe its stability to an association with soil colloids or with recalcitrant cellulosic material present in soil.     

Characterization of a flint maize (Zea mays var. indurata) Italian landrace, II. Genetic diversity and relatedness assessed by SSR and Inter-SSR molecular markers

A comparative characterization of 10 field populations of the maize (Zea mays var. indurata) landrace Nostrano di Storo was carried out using different types of PCR-based markers. The inbred line B73 and three synthetics (VA143, VA154 and VA157) selected from as many landraces were also used. Genetic diversity and relatedness were evaluated over 84 SSR and 53 I-SSR marker alleles using a total of 253 individual DNAs. Up to 23 alleles per SSR locus were scored while the average effective number of alleles per population was 6.99. Nei's total genetic diversity as assessed with SSR markers was H_T = 0.851 while the average diversity within populations was H_S = 0.795. The overall Wright's fixation index F_ST was as low as 0.066. Thus, more than 93% of the total variation was within population. Unique alleles over all SSR loci were found for six populations. An average of 17.7 marker alleles per I-SSR primer were scored with an effective number of marker alleles per locus of 1.34. The Shannon's diversity information index over all populations and I-SSR loci was 0.332, varying from 0.286 to 0.391. The extent of differentiation between populations was as low as G_ST = 0.091. Dice's genetic similarity matrices were estimated for both SSR and I-SSR markers. The mean genetic similarity coefficients within and between populations were respectively 0.269 and 0.217, for SSR markers, and 0.591 and 0.564, for I-SSR markers. UPGMA dendrograms displayed all field populations but one clustered into a distinct group, in which the synthetic VA154, selected from the Marano Vicentino landrace, was also included. One field population and the other two synthetics were clustered separately as well B73. The matrix correlation assayed by the Mantel's correspondence test was as high as 0.908. Findings suggest that, although a high variability can be found among plants, most plant genotypes belong to the same landrace called Nostrano di Storo. Although gene flow from commercial hybrids might have occurred, the large number of polymorphisms and the presence of both unique alleles and alleles unshared with B73 and synthetics are the main factors underlying the value of this flint maize landrace as a source of genetic variation and peculiar germplasm traits. Because of its exclusive utilization for human consumption, such a molecular marker characterization will be a key step for obtaining the IGP mark and so promote the in situ conservation and protection of the landrace Nostrano di Storo.     

A comparison of the biology of Eisenia fetida and Eisenia andrei (Oligochaeta)

Summary Specimens of locally occurring Eisenia fetida were compared with specimens of E. fetida and E. andrei obtained from France. All specimens were cultured in the laboratory under controlled conditions and growth, maturation, cocoon production, hatching success, and the number of hatchlings were compared. The results showed some differences between the two forms. The eventual worm biomass was the same for both, although the growth reats and the rate at which maturity was attained differed. E. andrei had a higher cumulative cocoon production. Although the local worms resembled E. andrei in appearance their cocoon production rate resembled that of E. fetida from France. E. andrei produced higher numbers of hatchlings per cocoon. The results show that the biology of the two species/forms is similar. The study did not provide convincing proof to substantiate a taxonomic distinction between the two forms of Eisenia.     

Effect of increasing oxygen concentration on total denitrification and nitrous oxide release from soil by different bacteria

Summary The effect of increasing oxygen concentrations (0, 5, 10 and 20 Vol% O₂) on total denitrification and N₂0 release was studied in model experiments using a neutral pH loamy soil relatively rich in easily decomposable organic matter and supplied with nitrate (300 g nitrate N/g dry soil). The sterilized soil was inoculated with three different denitrifying bacteria (Bacillus licheniformis,Aeromonas denitrificans andAzospirillum lipoferum) and incubated (80% WHC, 30°C). The gas volume was analysed for O₂, CO₂, N₂O, NO and N₂ by gas chromatography and the soil investigated for changes in ammonium, nitrite, nitrate, pH, total N and C as well as water-extractable C. WithB. licheniformis andAeromonas denitrificans total denitrification increased remarkably with increasing pO₂ as the result of intensified mineralization.Azospirillum lipoferum, however, showed the highest activity at 5 vol% O₂. WithB. licheniformis N₂O was released only in anaerobic conditions and at 5 Vol% O₂ (maximum) or 10 Vol% 02, but not at 20 Vol%, whereasAeromonas denitrificans produced N₂O only in the presence of He gas (maximum) or at 5 Vol% O₂. In contrast to these bacteria, N₂O production withAzospirillum lipoferum was restricted to 10 Vol% O₂ (maximum) and to 20 Vol% 02, with some traces at 5 vol% O₂. With a certain set of conditions, total denitrification and N₂O formation seem to be governed by the mineralization rate of the organisms in question. The increased demand for electron acceptors by a high turnover rate rather than the presence of anaerobic conditions seems to have determined the rate of denitrification.     

Yield response of spring wheat cultivars (Triticum aestivum and T. turgidum) to inoculation with Azospirillum brasilense under field conditions

Summary Eight commercial Israeli spring wheat cultivars (six Triticum aestivum and two T. turgidum) grown with 40 and 120 kg N/ha were tested for responses to inoculation with Azospirillum brasilense. At the low level of N fertilization (40 kg/ha), five cultivars showed significant increases in plant dry weight measured at the milky ripe stage; however, by maturation only the cultivar Miriam showed a significant increase in grain yield. Two cultivars, which had shown a positive inoculation effect at the earlier stages, had a significant decrease in grain yield. No significant effect of inoculation was found at the high N level. To confirm those results, four wheat (T. aestivum) cultivars were tested separately over 4 years in 4 different locations under varying N levels. Only Miriam showed a consistently positive effect of Azospirillum inoculation on grain yield. Inoculation increased the number of roots per plant on Miriam compared with uninoculated plants. This effect was found at all N levels. Nutrient (N, P and K) accumulation and number of fertile tillers per unit area were also enhanced by Azospirillum, but these parameters were greatly affected by the level of applied N. It is suggested that the positive response of the spring wheat cultivar Miriam to Azospirillum inoculation is due to its capacity to escape water stresses at the end of the growth season.     

Genetic diversity in the Olive tree (Olea europaea L. subsp. europaea) cultivated in Portugal revealed by RAPD and ISSR markers

To assess the genetic diversity of the most important olive cultivars used in Portugal, a base collection was established with two hundred and one accessions of eleven cultivars from the different agro-ecological-regions (AER) of olive oil production. Inter-cultivar diversity was evaluated using seven RAPD primers producing fifty-nine polymorphic markers that enable cultivar distinction. Discriminant analysis according to fruit use and AER revealed a genetic structure associated with local selection both for fruit exploitation and agro-ecological adaptation. Intra-cultivar diversity of the ancient cultivar Galega was also investigated. Three RAPD and five ISSR primers produced ninety-three polymorphic markers upon seventy-seven accessions from five AERs. Total accession discrimination was achieved. UPGMA clustering and discriminant analysis revealed that the genetic diversity was predominantly structured according to accessions origin. The within and among AER variation revealed by AMOVA supported this genetic structure and showed a high proportion of intra-AER variability. These evidences suggest that Galega is composed by a mixture of different genotypes adapted to local conditions, indicating that this cultivar is in an early stage of domestication and should be treated as a landrace instead of a uniform cultivar. The assessment of Galega genetic diversity within each of the five AERs indicated the highest significant level (H_g = 6.23 at p< 0.001) in Ribatejo-Santarém. This finding associated with the distinctiveness of Galega in relation to other Portuguese cultivars and with the recent insights of olive tree domestication allowed us to hypothesize that Ribatejo-Santarém was the ecological region of origin and dispersion of this ancient cultivar.     

Modelling spatial and temporal variability of denitrification

Summary Denitrification shows both spatial and temporal variability. Any attempt to model the process must take this into account. A model has been developed in which the soil is treated as a large assembly of potentially denitrifying microsites (a modification of the hot-spot concept). Chemical and biological heterogeneity is represented by a log-normal distribution of microsite respiration potential. Structural heterogeneity (where present) is accommodated by associating individual microsites with soil aggregates, the radius of which varies log-normally. Spatial variation arises naturally from the existence of microsites. Model microsites are assumed to be in a state of pseudo-equilibrium (a steady state). This means that they respond rapidly to any perturbation; it does not imply that they are static. A pseudo-equilibrium model can readily encompass temporal variation provided that the response time of the system is relatively short. Examination of the response times of typical model microsites, by numerical solution of the partial differential equations governing the transient processes occurring within them, suggests that in soils with few large (greater than 10^-2m in radius) denitrifying microsites the steady-state approximation is probably adequate. Where denitrification occurs predominantly in large microsites, however, a pseudo-equilibrium model is inappropriate.     

Vorarbeiten zur monographischen Darstellung von Wildpflanzensortimenten:Secale L

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.

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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.

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: 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. . .

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

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

Beiträge zur Kulturpflanzen-Flora I

Zusammenfassung Folgende Arten der GattungAmaranthus L. werden zur Körnergewinnung angebaut:A. caudatus L. (mit ssp.caudatus und ssp.mantegazzianus (Passer.) Hanelt),A. cruentus L. undA. hybridus L. em. Robins. convar.erythrostachys (Moq. in DC.) Thell. Die Einordnung und Benennung dieser Sippen werden erörtert. Ihre geographisch weit getrennten Anbauareale in Mittel- und Südamerika sowie in Asien, vor allem Indien bis China, haben bei den Diskussionen um vorkolumbische transpazifische Kulturbeziehungen zwischen Amerika und Asien eine Rolle gespielt. Alle drei Arten sind eindeutig amerikanischen Ursprungs, sie gehören zu den ältesten Kulturpflanzen der indianischen Landwirtschaft. Dagegen liegen keinerlei Belege für einen entsprechend alten Anbau in Asien vor. Vieles spricht dafür, daß sie über Europa, ursprünglich als Zierpflanzen, dorthin gelangten (16.–17. Jahrhundert) und durch die Übertragung der Art und Weise der Nutzung bereits bekannter Kulturpflanzen in den Ackerbau der betreffenden Gebiete übergingen.Im Gegensatz dazu stehen die sowohl in systematischer wie geographischer Hinsicht unterschiedenen Gemüsearten der Gattung. Die wichtigsten von ihnen sindA. tricolor L. em. Fiori et Paol. undA. lividus L. em. Thell.; beide sind altweltlichen Ursprungs und werden in Süd- und Ostasien bzw. im südlichen Europa seit langem kultiviert. Einige weitere, früher z. T. als häufig angebaut bezeichnete Gemüse-Arten erwiesen sich als nur von lokaler Bedeutung (A. dubius Mart. ex Thell.,A. viridis L.) oder als reine Sammelpflanzen (A. celosioides H. B. K.,A. spinosus L.,A. graecizans L. em. Aschers.).

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Summary The following taxa of the genusAmaranthus L. are cultivated as grain amaranths:A. caudatus L. (ssp.caudatus and ssp.mantegazzianus (Passer.) Hanelt),A. cruentus L. andA. hybridus L. em. Robins. convar.erythrostachys (Moq. in DC.) Thell. Systematics and nomenclature of these taxa have been discussed. Their widely separated areas of cultivation in Central and Southern America resp. in Asia (especially in India and China) have suggested speculations about precolumbic transpacific cultural relations between America and Asia. All the mentioned species are doubtlessly of an American origin, they belong to the oldest cultivated plants of the American agriculture. There are no evidences which would prove a cultivation of a likewise long history in Asia. But there are many indications for an introduction via Europe to Asia originally as ornamentals which have been subsequently adopted by the agriculture of these Asiatic regions, utilizations of previously known cultivated plants having been transferred to them.The vegetable species of the genus are differentiated taxonomically and geographically from the grain amaranths. The most important are:A. tricolor L. em. Fiori et Paol. andA. lividus L. em. Thell., they are of Old World origin and have been grown already long ago in Southern and Eastern Asia resp. in Southern Europe. Some further species, hitherto supposed to be ± widely cultivated ones, proved to be only of local importance (A. dubius Mart. ex Thell.,A. viridis L.) or as taxa, growing spontaneously and only collected for foodA. celosioides H. B. K.,A. spinosus L.,A. graecizans L. em. Aschers.).

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Amaranthus L.:A. caudatus L. ( caudatus mantegazzianus (Passer.) Hanelt),A. cruentus L. A. hybridus L. em. Robins. convar.erythrostachys (Moq. in DC.) Thell. , . , ( ) , . . ; , , , 16–17 . , , . , , . ¶rt; :A. tricolor L. em. Fiori et Paol. A. lividus L. em. Thell.; , . , , (A. dubius Mart. ex Thell.,A. viridis L.) , (A. celosioides H. B. K.,A. spinosus L.,A. graecizans L. em. Aschers.).