Effects of Benzyl Adenine and Abscisic Acid on Grain Yield and Yield Components in Triticale and Wheat

Grain yield and yield components (grains per ear, grain weight, 1000-grain weight, ear weight, ear seed ratio and dry matter partitioning between ear and seed) were examined in a wheat genotype (PBW-343) with well-filled grains and a Triticale genotype (DT-46) with poorly filled grains (showing grain shrivelling) grown in pots. Six days after anthesis (DAA), benzyladenine (BA) @2 µg ear⁻¹ and abscisic acid (ABA) @4 µg ear⁻¹ were injected at the base of the mother shoot ear in both species. It was observed that, in both wheat and Triticale , BA increased the grain weight, grain number and partitioning of dry matter between ear and seed, whereas ABA decreased the grain weight, grain number and dry matter partitioning between ear and seed. However, these decreases were slower in Triticale than in wheat. BA treatment increased the grain dry matter accumulation, which in turn resulted in better filling of grains and increased the grain weight in both wheat and Triticale . The average grain weight of Triticale was lower than that of wheat. Thus, it appears that variation in grain weight between wheat and Triticale might be due to different availabilities of growth-promoting phytohormones such as cytokinins and assimilates.     

Survey of tick infestation and tick-borne ehrlichial infection of dogs in Ishigaki Island, Japan.

Twelve (54.5%) of 22 free-roaming dogs in Ishigaki Island had tick infestation identified as Rhipicephalus sanguineus. There were 121 ticks recovered and consisted of 28 females, 58 males, 22 nymphs and 3 larvae. Infection of dogs possibly with canine ehrlichial pathogens was examined by both indirect immunofluorescence assay and polymerase chain reaction (PCR). Two dogs of the 13 examined were sero-positive for the human granulocytic ehrlichia agent, and one of two dogs was PCR positive for Ehrlichia platys. This dog had platelet numbers slightly lower than normal value, however, no morulae were found within platelet on peripheral blood smear stained with Giemsa.     

Identification of the porcine cytomegalovirus major capsid protein gene.

A major capsid protein (MCP) gene homologue of porcine cytomegalovirus (PCMV) was identified. Sequence analysis indicated that the PCMV MCP gene is 4,026 nucleotides in length encoding a protein of 1,341 amino acid residues. The predicted molecular weight of the PCMV MCP is 151,456 Da, equivalent to those of other herpesvirus MCP counterparts. Phylogenetic analysis using herpesviral MCP gene sequences confirmed that PCMV is a betaherpesvirus with higher homology with human herpesvirus-6 and -7 than human and mouse cytomegaloviruses. The serum of pig experimentally infected with PCMV did not react with bacterially expressed MCP, suggesting that the PCMV MCP may not be related to the humoral immune response in the course of PCMV infection. Also, we established polymerase chain reaction (PCR) protocols using primers corresponding to MCP gene sequences for detection of PCMV infection. The PCR protocol would be effective for the diagnosis of slow-growing PCMV infection, for which traditional methods involving virus-isolation are not useful.     

Doxorubicin affects the cardiac muscarinic system in the rat.

During the study on the mechanism of doxorubicin-induced cardiotoxicity, we observed that a long incubation (4 hr) with doxorubicin reduced the maximal negative inotropic effects of a muscarinic receptor agonist, carbachol. The mechanism responsible for this doxorubicin-induced reduction of the efficacy of carbachol was examined in isolated guinea pig hearts. In isolated left atrial muscle preparations, 1 hr incubation with 100 microM doxorubicin caused a parallel right-ward shift of the concentration-response curves for carbachol, but a longer (4 hr) incubation with this agent (30, 100 or 200 microM), caused a significant reduction of the magnitude of the negative inotropic effect of carbachol in addition to the concentration-dependent parallel right-ward shift. The 4-hr incubation with these concentrations of doxorubicin also reduced the maximal negative inotropic effect of an adenosine A1 receptor agonist, R-phenylisopropyl adenosine (R-PIA), without affecting the potency of this agonist. Doxorubicin (1 to 100 microM) reduced [3H]quinuclidinyl benzilate (QNB) binding in a concentration dependent manner, but failed to alter [3HIR-PIA binding. The decrease in the magnitude of the maximal negative inotropic effect by doxorubicin was caused by changes in the muscarinic system at steps common to the transduction of muscarinic and adenosine A1 receptor mechanisms.     

Detection of a broad range of potato viruses in a single assay by mechanical inoculation of herbaceous test plants

To optimize mechanical inoculation of test plants as part of the regulated post-entry quarantine testing of stolon- and tuber-forming Solanum spp. (including potato), nine test plant species have been screened for their ability to detect 22 potato-infecting viruses. These included all the common mechanically transmissible potato viruses and most of the viruses found in potato incidentally. The symptoms observed after mechanical inoculation are shown for each combination of test plant species and virus. Under given conditions, Nicotiana occidentalis -P1 and Nicotiana hesperis -67A were found to detect reliably 20 and 18 out of 22 viruses respectively. These and former results on the seed-transmissible viruses and Andean potato mottle virus demonstrate that these Nicotiana species are very suitable for post-entry quarantine testing. Addition of either Chenopodium amaranticolor or Chenopodium quinoa to these two species may slightly extend the range of viruses. Therefore, using C. amaranticolor / C. quinoa , N. hesperis -67A and N. occidentalis -P1 for the biological screening of imported Solanum spp. will improve both the efficiency and the quality of post-entry quarantine testing.