Untersuchungen zur Stabilität und Vitalität an Systemen balancierter tertiärer Trisomie bei Gerste

Zusammenfassung Bei 112 Linien 25 verschiedener BTT-Systeme erwies sich die genetische Stabilität der Systeme in den meisten Fällen als gut bis sehr gut, gemessen an der Frequenz disom-fertiler Rekombinanten. In speziellen Kreuzungstests ergaben sich Hinweise auf mögliche Stabilitätsstörungen durch Pollentransmission des Zusatzchromosoms nur bei einem von neun geprüften Systemen.Die Vitalität der trisomen Pflanzen bei den verschiedenen BTT-Systemen ist sehr unterschiedlich und von der jeweils vorliegenden Segmentzusammensetzung des Zusatzchromosoms abhängig. Bezogen auf diploide Pflanzen gibt es alle Übergänge von Subletalität bis hin zu annähernd normaler Vitalität. Leistungsfähige BTT-Systeme sind relativ selten und können mit ausreichender Wahrscheinlichkeit nur entwickelt werden, wenn von einer genügend breiten Basis von Translokations-undmsg-Linien ausgegangen wird.

---

Studies on the stability and viability in systems of balanced tertiary trisomy in barley

Summary The genetic stability of 112 stocks out of 25 different BTT systems proved to be, in most cases, good to very good, in terms of the frequency of disomic fertile recombinants. There is only rare indication of instability caused by pollen transmission of the extra chromosome: In special crossing tests only one out of nine BTT systems tested showed transmission.The viability of trisomic plants is very diverse in the different BTT systems and depends on the specific segmental composition of the extra chromosome. As compared with normal diploids there are all types of trisomics ranging from sublethal to nearly normal ones. Efficient BTT systems are comparatively rare. They can be developed with good expectation provided a sufficiently broad basis of translocation andmsg lines is used.

---

112 25 . - . . - , 9 . . , . , , , msg-.

---

---

Herrn Professor Dr. Dr. h. c. mult.H. Stubbe zum 85. Geburtstag gewidmet.     

Near-infrared spectroscopy for analysis of chemical and microbiological properties of forest soil organic horizons in a heavy-metal-polluted area

In industrial areas, heavy metals may accumulate in forest soil organic horizons, affecting soil microorganisms and causing changes in the chemical composition of the accumulated organic matter. The objectives of this study were to test the ability of near-infrared spectroscopy (NIRS) to detect heavy metal effects on the chemical composition of forest soil O horizons and to test whether NIRS may be used to quantitatively determine total and exchangeable concentrations of Zn and Pb (Zn_t, Pb_t, Zn_ex, Pb_ex) and other chemical and microbial properties in forest soil O horizons polluted with heavy metals. The samples of O horizons (n = 79) were analyzed for organic C (C_org), total N and S (N_t, S_t), Zn_t, Pb_t, Zn_ex, Pb_ex, basal respiration (BR), microbial biomass (C_mic) and C_mic-to-C_org ratio. Spectra of the samples were recorded in the Vis-NIR range (400–2,500 nm). To detect heavy-metal-induced changes in the chemical composition of O horizons principal components (PC1–PC7) based on the spectral data were regressed against Zn_t + Pb_t values. A modified partial least squares method was used to develop calibration models for prediction of various chemical and microbial properties of the samples from their spectra. Regression analysis revealed a significant relationship between PC3 and PC5 (r = −0.27 and −0.34, respectively) and Zn_t + Pb_t values, indicating an effect of heavy metal pollution on the spectral properties of the O horizons and thus on their chemical composition. For quantitative estimations, the best calibration model was obtained for C_org-to-N_t ratio (r = 0.98). The models for C_org, N_t, and microbial properties were satisfactory but less accurate. NIRS failed to accurately predict S_t, C_org-to-S_t, Zn_t, Pb_t, Zn_ex, and Pb_ex.     

Methods for the investigation of metabolic activities and shifts in the microbial community in a soil treated with a fungicide

Samples from a sandy agricultural soil were treated with increasing amounts of a fungicide (Sportak). The effects on the soil microflora were investigated over several weeks by monitoring basal and substrate-induced respiration and basal and substrate-induced heat output. The microbial biomass, metabolic quotient (qCO₂), relative heat output (rqheat), lag phase of substrate use, and calorimetric: respirometric ratio were used as ecophysiological parametèrs. As structural and community-specific parameters, we recorded tryptophan contents and auxin metabolism, and calculated the ratios of fungal to bacterial respiration by antibiotic inhibition of substrate-induced respiration. Sportak either inhibited or stimulated the microbiota, depending on the length of exposure to the fungicide and the amount applied. Mineralization of dead biomass was reflected in increased soil tryptophan contents after the Sportak application. A shortened lag phase demonstrated inhibition and a prolonged lag phase stimulation of substrate use. This changed with the experimental phase. The rqheat and the calorimetric: respirometric ratio proved to be suitable parameters for the detection of stress metabolism (repair processes) in soil microbiota, because thermodynamic processes and catabolic and anabolic metabolism are taken into account at the same time. Following the application of Sportak, indole 3-acetic acid biosynthesis decreased while indole-3-ethanol biosynthesis increased, probably as a result of a transitional community shift from K-strategists towards r-strategists. It was not the fungicide but the formulation (mainly xylol) that damaged the organisms. A shift in the ratio of fungi to bacteria was also observed, suggesting that the bacteria were probably more sensitive to xylol than the fungi.     

Liquid chromatographic determination and identification of morantel-related residues as precursors of 3-(3-methyl-2-thienyl) acrylic acid (CP-20,107) in bovine milk

A simple liquid chromatographic (LC) method was developed to determine and identify incurred morantel-related residues in bovine milk by converting them to 3-(3-methyl-2-thienyl) acrylic acid (CP-20, 107). Key techniques in this method involve short-term digestion of milk in HCl to release residues convertible to CP-20, 107, isolation and alkaline hydrolysis of these precursors to CP-20, 107, and recovery of the product for LC analysis. Photochemical conversion of CP-20, 107 to its cis-isomer and separation by LC identifies the residue. A homolog (pyrantel), which is used as an internal standard, is hydrolyzed to 3-(2-thienyl) acrylic acid. These acrylic acid isomers are readily resolved by LC. The method was evaluated over the 1-4 ppb (ng/mL) range for accuracy and precision to assess its utility for withdrawal studies. Bovine milk supplemented with morantel at 1, 2, and 4 ppb and assayed in replicate (n = 7-8) over 4 trials gave mean values and standard deviations of 1.0 +/- 0.11, 2.0 +/- 0.24, and 4.0 +/- 0.44 ppb, respectively. A milk specimen containing physiologically incurred residues of morantel assayed 2.1 +/- 0.19 ppb in replicate (n = 5).     

Hypertension of renal origin: evidence for two different mechanisms

Antibody to angiotensin 11, or a specific peptide competitive inhibitor of angiolensin II, was used to investigate the role of the renin-angiotensin system in two types of renal hypertension in rats. The data indicate that angiotensin II is in fact critically involved in the pathogenesis of the form of renal hypertension in which one renal artery is clamped and the contralateral kidney is left in place, but that it probably plays no significant role in the maintenance of experimental renal hypertension in which the opposite kidney has been removed.     

Angiotensin-sodium interaction in blood pressure maintenance of renal hypertensive and normotensive rats

A specific inhibitor of angiotensin II was used in rats to investigate whether angiotensin is involved in the maintenance of blood pressure in one-kidney Goldblatt hypertension, in which plasma renin levels are not usually increased. The inhibitor produced marked falls in blood pressure, often down to normal levels in the hypertensive animals only when they were depleted in sodium and not after sodium repletion. Much lesser but still significant falls in blood pressure were also produced in normotensive sodium-depleted rats but not in repleted rats. We conclude that the importance of angiotensin for maintaining blood pressure is largely determined by its relation to available sodium or fluid volume, since the renin component in maintenance of either the hypertensive or the normotensive state could be exposed only by sodium deprivation. Therefore, volume expansion per se or other pressor factors may be involved in maintaining blood pressure of these sodium-replete normotensive or hypertensive animals.     

G protein signalling involved in host recognition and mycoparasitismrelated chitinase expression in Trichoderma atroviride

Mycoparasitic species of Trichoderma are commercially applied as biological control agents against various fungal pathogens. The mycoparasitic interaction is host specific and includes recognition, attack and subsequent penetration and killing of the host. Investigations on the underlying events revealed that Trichoderma responds to multiple signals from the host (e.g. lectins or other ligands such as low molecular weight components released from the host's cell wall) and host attack is ac…     

Pesticide and Heavy Metals Residue in Wastewater, Soil and Plants in Wastewater Disposal Site Near Al-Lajoun Valley, Karak / Jordan

Disposal of raw wastewater and sludge creates thepotential for pesticides and heavy metal contamination. Afield study was conducted to determine the residueconcentration level of chlorinated pesticides and four heavymetals (Zn, Pb, Cu and Ni) in raw wastewater, soils andplants at Karak raw wastewater disposal site. The resultsindicated that the investigated area was heavily contaminatedwith various types of pesticides. The distribution of different pesticides in soils and wastewater was influencedby the solubility of these pesticides such that the higherthe solubility the more is present in water phase and viceversa. Vinclozoline was the dominant pesticide in most of thesamples. Some pesticides of which application is restrictedto be used in Jordan, such as DDT and its metabolites, weredetected in the investigated area.Heavy metals existed in relatively higher concentrationsin soils than in wastewater, which was due to the high pH ofthe wastewater enhancing its precipitation. Zinc was thehighest among the analyzed heavy metals in both wastewaterand soils.The residue level of both heavy metals and chlorinatedpesticides were highest at the emission source decreasinggradually with distance.     

Flow-microcalorimetry measurements of aerobic and anaerobic soil microbial activity

Heat output can be used as an indicator of microbial activity and is usually measured in a microcalorimeter with closed ampoules. In long-term experiments particularly, interpretation of the data is hindered by the changing environment in the closed ampoules because of O₂ consumption and CO₂ enrichment. We used a combination of a flow-microcalorimeter and a gas chromatograph to measure the heat flux and CO₂ and N₂O production rates under controlled conditions. Simultaneous detection of the heat output and CO₂ emission allowed calculation of the calorimetric: CO₂ (Cal/CO₂) ratio. A mean ratio of-435 kJ mol^-1 CO₂ was detected in six different soils amended with glucose and incubated under aerobic conditions. This ratio indicated that CO₂ was the end-product of catabolism. In wet 10–12 mm soil aggregates of a gleyic vertisol amended with glucose, values of-285 kJ mol^-1 CO₂ under an aerobic and-141 kJ mol^-1 CO₂ under a N₂ atmosphere was determined. These findings indicated that fermentative metabolism occurred. The Cal/CO₂ ratio was not affected when enough NO _inf3 ^sup- was available and denitrification processes (N₂O production) were possible.