Phosphorus fertilization for rice and control of environmental pollution problems.

Aim of this study to review information on various aspects of P fertilization in rice i.e., P nutrition of rice, P response of rice plant, P availability in rice soils and P adsorption in rice soils for better understanding of P fertilization in rice culture. A substantial portion of the applied P along with the soil P is lost from rice fields to water bodies causing environmental pollution problems through eutrophication. These pollution problems can be minimized by using proper source of P as fertilizer, proper timing and methods of P fertilizer application, soil P management, transport management, use of plant growth promoting microorganisms which helps in efficient use of P by crops and use of green manure crops which improves soil fertility as well as helps in efficient use of P by crops.

[Screening for carrier state of Haemophilia B using indirect genomic detection]. / Konduktorszúrés indirekt géndiagnosztika alkalmazásával B haemophiliában.

The authors report the first data having applied the indirect genomic diagnosis in carrier screening in Hungary. 22 patients with haemophilia B and female family members of 14 out of them were examined by PCR based restriction fragment length polymorphism analysis. The combined use of 3 intra- and 1 extragenic polymorphisms have been examined at the same population. DNA fragments, containing the single nucleotide change polymorphic site (Xmnl, Hhal, Taql), or the 50 bp insertion/deletion element (Dde) were amplified. The products were digested by the appropriate restriction digestion enzyme and were detected on agarose gel following ethidium-bromide staining. 20 siblings were interested in the determination of their carrier-state. 15 (75%) of them could get definite diagnosis. The carrier-state was established in 7 cases, excluded in 8 subjects. For the remaining 5 participants studied, the absence of the parental DNA sample caused uncertainty, while in 2 cases (10%) none of the analyzed RFLP was informative. The heterozygosity rate, the gene and haplotype frequency were also recorded and compared with the international data. The indirect methods have proved to be sufficient and well suitable for routine carrier testing. The results provide the basis of the subsequent prenatal diagnosis.

Structure of the O-specific polysaccharides of the lipopolysaccharides of Xanthomonas campestris pv. vignicola GSPB 2795 and GSPB 2796.

The O-specific polysaccharides of Xanthomonas campestris pv. vignicola GSPB 2795 and GSPB 2796 were studied by sugar and methylation analyses, Smith degradation, ID, 2D 1H and 13C NMR spectroscopy. It was found that the polysaccharides are similar branched D-rhamnans lacking strict regularity, and their structures can be described as follows: [carbohydrate equation: see text] where Rha(v) is present in a non-stoichiometric amount, which varies from strain to strain.

Structure of the O-chain polysaccharide of the lipopolysaccharide of Xanthomonas campestris pv. manihotis GSPB 2755 and GSPB 2364.

The O-chain polysaccharide of the lipopolysaccharide of Xanthomonas campestris pv. manihotis strains GSPB 2755 and GSPB 2364 was studied by sugar and methylation analyses and 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, and H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC) experiments. The polysaccharide was found to contain L-rhamnose and L-xylose in the ratio 3:1, and the following structure of the tetrasaccharide repeating unit was established: [formula: see text]

[Treatment of chronic myeloid leukemia with interferon-alpha]. / Chronicus myeloid leukaemia kezelése interferon-alpha-val.

The authors have treated 38 patients with chronic phase chronic myeloid leukemia in their single center in the last five years. Conventional chemotherapy provided about 40-50% hematological response, interferon-alpha seems to be more effective, complete hematological remission occurred in 65%. Interphase cytogenetics and fluorescein in situ hybridisation technique was used to measure the cytogenetic response. They observed complete cytogenetic remission in two cases (8%), major response in 11 (39%), minor response in 4 (15%) and minimal response in 4 cases (15%). Interferon-alpha is an effective, well-tolerated medicine in the treatment of chronic myeloid leukemia.

A method for selecting Trichoderma strains antagonistic against Sclerotinia minor.

Thirty strains of T. hamatum, T. harzianum, T. koningii, T. longibrachiatum and T. viride were selected for in vitro mycoparasitic activity against Sclerotinia minor. High destruction of sclerotia (up to 70% in two weeks) was caused by antagonists only at 25 degrees C, in autoclaved soil, because the optimum temperature for radial growth of Trichoderma strains (25-30 degrees C) was significantly higher than those of phytophatogenic fungus (20 degrees C). The most active strains, which were selected also for competitive saprophytic ability could enhance the percentage of decayed sclerotia 5-9 fold over the control even after 1 week under non sterile conditions. A silicon rubber fixation technique was developed for recovery of irregularly shaped S. minor sclerotia.

Effect of some environmental factors on Rhizobium and Bradyrhizobium strains.

Effects of different abiotic factors (acidity, salinity, nitrate and temperature) on growth rate of root-nodule bacteria (Rhizobium and Bradyrhizobium) strains were investigated in vitro. Strains isolated from Vicia faba L., Coronilla varia L. and Lupinus albus L. exhibited a large variation in tolerance of the above-mentioned factors. These bacteria should be screened under stimulated conditions for enhanced survival before selection to be used for commercial inoculant production. Linear correlation matrix data were useful to find the appropriate concentrations for the selection of the tolerant strains.

Metal sensitivity of some symbiotic N2-fixing bacteria and Pseudomonas strains.

An investigation was carried out to determine the sensitivity of different soil microbes (Rhizobium, Bradyrhizobium and Pseudomonas) to various metals (Cu2+, Zn2+, Co2+, Mn2+, Mo2+ and Fe2+) in vitro. Sulphate and chloride forms of these microelements were used (except Mo2+ as Na2Mo04) in 0.1, 1.0 and 10 micrograms/ml concentrations in modified YEM and nutrient broth. Growth (optical density, OD550 and OD640) of bacterium inoculated (approx. 10(6) CFU/ml) tubes, was measured spectrophotometrically after 48 h of incubation of 28 degrees C in a rotary shaker (150 rpm). Data of triplicate samples are shown as percent of control tubes (inoculated, free from treatments) and after an analysis of variance SE was calculated. Strains of Rhizobium leguminosarum proved to be the most sensitive to Cu2+, Zn2+ and Co2+. The slow growing Bradyrhizobium and plant growth promoting (PGPR) Pseudomonas isolates, however, were affected only at the highest (10 micrograms/ml) dose of these elements. In contrast Mn2+, Mo2+ and Fe2+ microelements were stimulatory for the growth of all investigated soil microbes. Sulphate forms of the most harmful Cu2+ and Zn2+ cations were more toxic than the chloride forms. An especially high diversity was found among the R. leguminosarum bv. viceae isolates. Monitoring the sensitivity of these microbes has a primary importance for selection of ecologically diverse isolates, as potential inocula in heavy-metal affected soils.

Some environmental factors influencing the survival of Rhizobium leguminosarum bv. viceae.

Investigations were carried out to monitor the sensitivity of Rhizobium leguminosarum bv. viceae strains to various environmental stress-factors (salinity, pH, Al3+, Ca2+, Mg2+) and select them as potential candidates for Vicia faba inoculation. In the range between pH 5.0 and 10.0, the salt effect of 10-500 mM NaCl, Ca2+, Mg2+ (as chlorides and sulphates), Al2O3 and KAl (SO4)2 (25-400 microM) were tested in modified yeast-mannitol (YEM) liquid medium. Cell density of the suspensions inoculated with R. leguminosarum bv. viceae strains (initial cell-number 10(6) CFU/ml) were measured spectrophotometrically after 48 h incubation in a rotary shaker (rpm 150) at 28 degrees C. Data of optical density (OD550) are shown as percent of control (inoculated, free from treatments, pH 7.0) tubes. It was established, that results of tolerancy were in agreement with those found earlier for Rhizobium sensitivity. Strain of Lóbab Z (isolated in Hungary) however proved to have an especially outstanding survival in any media tested in vitro. Lowest observed effect concentrations (LOECs) were: 500 mM NaCl, 200 microM Al3+ (as Al2O3 or KAl (SO4)2), 50-100 mM Mg2+, and 200-300 mM Ca2+. For the Al3+, Ca2+ and Mg2+ cations, there was no variation between the stress-effect of sulphate and chloride anions. Both forms of Ca2+, however significantly reduced the growth potential of R. leguminosarum bv. viceae strains.