Promotion of homoeologous chromosome pairing in hybrids of Triticum aestivum × Aegilops variabilis

Intergeneric hybrids of Triticum aestivum variety Lu-26 and ph1b mutant of the cultivar Chinese Spring were produced with three accessions, A, B, and E, of Aegilops variabilis. Significant differences were found in the amount of homoeologous chromosome pairing at meiotic metaphase I. Hybrids between wheat variety Lu-26 and accessions A and B of Ae. variabilis showed very little pairing, as indicated by the chiasma frequency of 1.0 and 1.5 per cell, respectively. Hybrids between Lu-26 and accession E, on the other hand, showed significantly increased homoeologous pairing (mean chiasma frequency, 12.6/cell). The level of such pairing was essentially the same as that between the hybrids of ph1b 'Chinese Spring' × Ae. variabilis accessions A and B. However, when the ph1b mutant was hyridized with accession E, the level of chromosome pairing increased significantly (mean chiasma frequency, 17.52/cell). This is indicative of the presence of pairing promoter gene(s) in Ae. variabilis accession E, which are epistatic to the wheat Ph1 allele and positively interact with its mutant form to further increase the ph1b ceiling to homoeologous pairing in wheat.Key words: Triticum aestivum, ph1b mutant, Aegilops variabilis, intergeneric hybrids, homoeologous pairing.

Production and cytogenetics of Triticum aestivum L. hybrids with some rhizomatous Agropyron species

Intergeneric hybrids between Triticum aestivum L. and conventional rhizomatous Agropyron species were produced in variable frequencies. They were recovered in high percentage frequencies for T. aestivum cultivars with A. acutum (14.6%), A. intermedium (48.0%), A. pulcherrimum (53.3%), and A. trichophorum (46.6%). The crossability percentages with the highly crossable cultivar 'Chinese Spring' for these Agropyron species accessions were 33.12%, 65.0%, 53.3%, and 65.4%, respectively. Autosyndetic associations of two of their three genomes gave mean meiotic chromosome association data of 17.0 I (univalents) +1.53 II (ring bivalents) + 7.04 II (rod bivalents) +1.43 III (trivalents) +0.05 IV (quadrivalents) +0.01 IV (pentavalents) for A. acutum and of 21.8 I + 1.56 II (rings) +7.22 II (rods) +0.84 III + 0.04 IV for A. intermedium. Chromosome pairing at metaphase I was comparatively lower for A. pulcherrimum (34.4 I + 0.2 II (rings) +3.4 II (rods) +0.14 III) and A. trichophorum (36.7 I + 0.35 II (rings) +2.26 II (rods) + 0.04 III) hybrids with T. aestivum. Hybrids of wheat with A. campestre and A. repens were obtained in low frequency. Direct crossing did not permit T. aestivum/ A. desertorum hybridization. However, by utilizing the 2n=10x=70 A. repens/A. desertorum amphiploid as the pollen source, hybridization with T. aestivum did indeed occur. Aneuploidy was prevalent in this hybrid combination while all other hybrid combinations were apparently normal.

Measurement of wastewater treatment efficiency by fluorescence and UV absorbance

The degree of chemical treatment in terms of removal of organic matter from different wastewaters has been investigated by employing potassium ferrate (K2FeO4) and ozone in various combinations. The study was performed in both the batch and the continuous flow systems. The treatment efficiency was determined through three different methods, i.e., chemical oxygen demand (COD), fluorescence and ultraviolet (UV) absorption. Fluorescence and UV absorption techniques were employed due to their specificity in measurement of humic substances, aromatic compounds and heterocyclic systems, whereas COD is a general parameter for the estimation of total organic matter. Fluorescence and UV absorbance values were correlated with respective COD values.

Effect of molybdenum deficiency on the growth and metabolism of corn plants raised in sand culture

Molybdenum deficiency decreased the dry matter yield, tissue concentration of molybdenum, and chlorophyll content of corn (Zea mays L. cv. T.41) plants. Compared with the normal (control) plants, leaves of molybdenum-deficient plants had significantly lower activities of nitrate reductase, catalase, aldolase, and alanine aminotransferase and higher activities of peroxidase, β-glycerophosphatase, and ribonuclease. Within 72 h of supplying molybdenum (50 μM) to molybdenum-deficient plants, chlorophyll concentration, soluble protein, and activities of nitrate reductase, catalase, and alanine aminotransferase showed considerable recovery but the increase in the peroxidase activity was further enhanced. Supply of molybdenum to molybdenum-deficient plants did not significantly affect the activity of aldolase, ribonuclease, and β-glycerophosphatase.

Amoxycillin trihydrate (Ibeamox) in the treatment of pyogenic meningitis-a preliminary report

Amoxycillin a new broad spectrum antibiotic has been found to be effective against common gram positive and negative bacteria diagnosed in clinical practice. Moreover, it achieves higher blood levels as compared to Ampicillin. Since it was available only for oral use it had not been tried in the treatment of bacterial meningitis. Recently Amoxycillin Trihydrate became available for parenteral administration. Here we report its use as a single drug in 11 cases of Pyogenic meningitis. The dose administered by intravenous route was 200-400 mg/kg/day. All the cases recovered. Only three had minor neurological sequelae. Amoxycillin Trihydrate appears to be a safe and effective drug as there were no side effects or toxic manifestation even with the high dosage schedule.