Effect of gibberellic acid on flowering and the thebaine yield of different clones of Papaver bracteatum

Two foliar applications of gibberellic acid (GA₃, 250 mg l^–1) enhanced the flowering in various clones of Papaver bracteatum. The most pronounced effects were obtained in late flowering clones in which GA₃ increased significantly the number and weight of the capsules and thebaine yield per plant.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 1267-E, 1984 series.     

Deschampsia austrobohemica—a new species fromDeschampsia caespitosa complex

Deschampsia austrobohemica from the South Bohemia is described. Besides the morphological characters the ecological data are given.     

Phylogenetic studies in Papaver section Oxytona: cytogenetics of the species and interspecific hybrids

Summary Chromosome behaviour at meiosis was studied in the F₁, F₂, and backcross generations, in the three species of Papaver section Oxytona, and in artificially induced autopolyploids of P. bracteatum. Close homology was found between the genome of P. bracteatum and that of the two polyploid species, P. orientale and P. pseudo-orientale, suggesting that the P. bracteatum genome is present in both polyploid species. A genetic mechanism controlling bivalent pairing in the polyploid species is suggested. Further study is needed for finding out the breeding potential of interspecific hybridization in section Oxytona.Contribution no. 1569-E, 1985 series from the Agricultural Research Organization, The Volcani Center, Bet Dagan 50 250. Israel     

Changes in crossing over frequency in barley caused by different concentrations of calcium and magnesium

The linkage of barley between rough versus smooth awns and long versus short rachilla hair was influenced by different amounts of Ca and Mg. It was found, that not only lack, but also excess causes an increase of the recombination frequency as against the control.     

Metabolism of benzo[a]pyrene in human skin xenografts.

Although a human neonatal foreskin graft to a nude mouse has been shown to be morphologically intact for several months after establishment, the feasibility of using this system for carcinogenesis studies has not been widely investigated. In this study, we have investigated the metabolism of benzo[a]pyrene (BaP) in human skin xenografts after the topical application of different concentrations of [3H]BaP (0.5 microgram-10.0 micrograms and 20 muCi/graft) for 2 h and 1.0 micrograms [3H]BaP for various intervals of time up to 4 h. Significant amounts of different organic solvent soluble metabolites were observed in all the different samples. The increase in the amounts of the organic solvent soluble metabolites was linear over the 0.5 microgram to 5.0 micrograms/graft range. When 1.0 microgram [3H]BaP was applied to each graft, the maximum production of the organic solvent soluble metabolites was observed 10 minutes after treatment and it then decreased with time. Diols were the major metabolites detected in each of the experiments, followed by phenols, and then tetrols. The levels of water soluble glucuronide and sulfate conjugates were almost equivalent for each treatment over the same range of application of BaP per graft. The combined levels of these conjugates and the non-extractable organic soluble metabolites in the residue, generally ranged between 7-24% of the total metabolites in the various experiments.