Chronology development of Hiba arbor-vitae (<Emphasis Type="Italic">Thujopsis dolabrata</Emphasis> var. <Emphasis Type="Italic">hondae</Emphasis>) and dating of timbers from an old building

Two site chronologies of the ring widths of Hiba arbor-vitae (Thujopsis dolabrata var. hondae) were developed for the northern-most part of Honshu Island, Japan (AOTK: 1715-2001, AOSO: 1753-2000). These are highly coherent, satisfactorily indicating high values of expressed population signal and mean correlation between trees. The two series were merged into a single composite chronology, spanning a period of 287 years from 1715 to 2001, because they correlated significantly with each other. The developed chronology is the first quality-controlled tree-ring chronology for this region extending back to the eighteenth century. Using the master chronologies, we successfully crossdated three historical timbers from an old building near the sampling sites. The tree-ring dates strongly supported the documented construction date of the building. It is revealed that Hiba arbor-vitae has sufficient potential to contribute to future dendrochronological study in this region by extending the chronologies back into the past.     

Association of a single nucleotide polymorphism in ribosomal protein L27a gene with marbling in Japanese Black beef cattle

Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The c2‐11#2 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low‐marbled and high‐marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the ribosomal protein L27a (RPL27A) gene containing the c2‐11#2 EST sequence was considered as a positional candidate for the gene responsible for marbling. In the present study, a single nucleotide polymorphism (SNP) in the promoter region of the RPL27A, referred to as g.3109537C>T, was detected between the 2 steer groups. The SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. The effect of genotypes of the SNP on the predicted breeding value for subcutaneous fat thickness was not statistically significant. These findings suggest that the RPL27A SNP may be useful for effective marker‐assisted selection to increase the levels of marbling in Japanese Black beef cattle.     

Effect of ruminal protozoa on fecal microbiota in cattle using terminal restriction fragment length polymorphism

The effect of the presence of ruminal protozoa on the composition of fecal microbiota in cattle was investigated. Six castrated Holstein cattle (mean bodyweight 137 kg) were divided into two groups: three faunated and three unfaunated. The fecal bacterial composition of the faunated and unfaunated cattle was compared using a culture method and by terminal restriction fragment length polymorphism (T‐RFLP) analysis. Approximately 0.4 to 2.3% of the bacterial cells detected by microscopy formed colonies on medium 10. The major terminal restriction fragments were detected in the T‐RFLP profiles generated by Hha I and Msp I digestion in both the faunated and unfaunated cattle. In particular, the Bacteroides group, the Clostridium coccoides group and the Clostridium leptum subgroup might be the known bacterial groups that protozoa influence by Msp I digestion. From the dendrogram analysis by T‐RFLP patterns, the faunated and unfaunated cattle were divided into two clusters, I and II, respectively. These results suggest that absence of protozoa in the rumen changes the composition of fecal bacteria.     

Evaluation of enzyme-linked immunosorbent assay (ELISA) and immunofluorescent antibody (IFA) test for the detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibody in pigs from conventional farms

To evaluate the immunofluorescent antibody (IFA) test and enzyme-linked immunosorbent assay (ELISA) for detecting the porcine reproductive and respiratory syndrome virus (PRRSV) antibody, conventional pigs in PRRSV-positive and -negative commercial farms were examined. Antibody development patterns in ELISA and IFA tests were compared in 3 week old piglets experimentally infected with the PRRSV. The virus was detected from 2 days post infection (PI) and then the antibody titers and S/P ratios rose by both methods. A total of 208 serum samples were collected from 4 PRRSV-negative farms and 210 samples from PRRSV-positive farms, and were tested for the PRRSV antibody by IFA and ELISA. The titer of 64 should be set as the cut-off point in IFA for field sera. Similarly, the cut-off S/P ratio should be set at 0.4 in ELISA. A high degree of correlation was observed between antibody titers by the two methods in these 418 samples, with a correlation coefficient of 0.84. The coincidence rate between the two tests was 84.7% (354/418). In non-coincident cases, ELISA was able to detect the antibody with a low titer in the serum samples which were negative in IFA but from PRRSV positive farms. ELISA was more sensitive than IFA to detect PRRSV infected animals or farms.     

Phylogenetic relationships of Ralstonia solanacearum species complex strains from Asia and other continents based on 16S rDNA, endoglucanase, and hrpB gene sequences

The 16S rDNA, endoglucanase, and hrpB genes were partially sequenced for Asian strains of Ralstonia solanacearum spp. complex, including 31 strains of R. solanacearum and two strains each of the blood disease bacterium (BDB) and Pseudomonas syzygii. Additional sequences homologous to these DNA regions, deposited at DDBJ/EMBL/GenBank databases were included in the analysis. Various levels of polymorphisms were observed in each of these DNA regions. The highest polymorphism (approximately 25%) was found in the endoglucanase gene sequence. The hrpB sequence had about 22% poly-morphism. The phylogenetic analysis consistently divided the strains into four clusters, as distinctly shown on the phylogenetic trees of 16S rDNA, hrpB gene, and endo-glucanase gene sequences. Cluster 1 contained all strains from Asia, which belong to biovars 3, 4, 5, and N2. Cluster 2 comprised the Asian strains of R. solanacearum (as biovars N2 and 1) isolated from potato and clove, as well as BDB and P. syzygii. Cluster 3 contained race 3 biovar 2 strains from potato, race 2 biovar 1 strains from banana, and race 1 biovar 1 strains isolated from America, Asia, and other parts of the world. Cluster 4 was exclusively composed of African strains. The results of the study showed the distribution and diversity of the Asian strains, which are present in three of the four clusters. The similarity of Asian strains to those in the other regions was also observed.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AY464950 to AY465050     

Genetic diversity of <Emphasis Type="Italic">Ralstonia solanacearum</Emphasis> strains causing bacterial wilt of solanaceous crops in Myanmar

In 2013 and 2014, an extensive survey of bacterial wilt in Myanmar was performed, and 70 strains of Ralstonia solanacearum (Rs) were collected from wilting plants of tomato, potato, chili and eggplant. Myanmar Rs strains were characterized by traditional and molecular methods. Polymerase chain reaction (PCR) test using Rs-specific primer set amplified one specific band (281-bp) from template DNA of all strains. Pathogenicity tests on the four solanaceous plants differentiated the strains into six pathogenic groups. Biovar determination tests showed that biovar 3 strains predominated (63%) among all Rs strains. Biovar 4 strains (7%) were obtained from both tomato and chili strains, whereas biovar 2 (30%) strains were isolated only from potato. Multiplex-PCR analysis indicated that tomato, eggplant and chili strains belonged to phylotype I, whereas potato strains comprised phylotype I and phylotype II. Strains in phylotype I, which was suggested to have originated from Asia, were the most prevalent in all surveyed areas. Phylogenetic analysis based on the endoglucanase (egl) gene sequences revealed that Myanmar strains partitioned into two major clusters that corresponded to phylotype I and II. Strains in phylotype I were further divided into seven subclusters, each corresponding to a distinct sequevar (15, 17, 46, 47, 48, unknown 1 or unknown 2). All strains in phylotype II belonged to sequevar 1. This is the first comprehensive report of the presence of diverse Rs strains in Myanmar.     

Analysis of sources of oxolinic acid-resistant field strains of <Emphasis Type="Italic">Burkholderia glumae</Emphasis> based on rep-PCR analysis and nucleotide sequences of <Emphasis Type="Italic">gyrB</Emphasis> and <Emphasis Type="Italic">rpoD</Emphasis>

Repetitive sequence-based polymerase chain reaction (rep-PCR) analysis using BOX and ERIC as primers showed a highly divergent phylogeny among field strains of Burkholderia glumae. To elucidate the sources of oxolinic acid (OA) resistance in field strains of B. glumae isolated from rice seedlings cultivated in Mie, Toyama, and Iwate prefectures, Japan, the amino acid at position 83 of GyrA (GyrA83), which is involved in OA resistance, and the DNA patterns from the rep-PCR and the partial nucleotide sequences of gyrB and rpoD from various strains were analyzed. The ten Mie strains, in which GyrA83 was isoleucine (Ile), were divided into two groups based on the band patterns in rep-PCR analysis, although the nucleotide sequences of gyrB and rpoD were identical among the strains. Based on the band patterns in the rep-PCR analysis and the gyrB and rpoD sequences, two highly OA-resistant Toyama strains, Pg-13 and Pg-14, for which GyrA83 was serine (Ser) and Ile, respectively, were in the same lineage. This suggests that the bacteria might acquire OA resistance faster than phylogenic diversity as determined with the repetitive sequences BOX and ERIC and with gyrB and rpoD. Furthermore, three Iwate strains (H95, H101, and H104), isolated from seedlings of different cultivars grown in different years and having Ile at GyrA83, are probably in the same lineage, suggesting that OA-resistant bacteria might be transferred among different cultivars.     

Analysis of phenol-resorcinol-formaldehyde resins

A method based on high-performance liquid chromatography (HPLC) and proton magnetic resonance (PMR) spectroscopy for analyzing phenol-resorcinolformaldehyde (PRF) resins is reported. The equations that describe the number-averaged structures of PRF resins in terms of the PMR absorption intensities of acetylated resins have been derived on the basis of the work of Woodbrey et al. and Anderson et al. The P/R molar ratio of the resin calculated from the PMR intensities was in good agreement with the synthetic P/R molar ratio when correction was made for the loss of phenol evaporated during the drying process that preceded the acetylation. The number-averaged molecular weight (M_n) of the acetylated resin calculated from the PMR intensities agreed with the M_n determined by cryoscopy. Unreacted phenol and resorcinol could be determined by analyzing the water-soluble fraction of the resin by use of high-performance liquid chromatography.Part of this paper was presented at the 4th annual meeting of the Kyushu branch of the Japan Wood Research Society, Miyazaki, November 1997, and at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998     

Kinetics of the hydroxymethylation of phenol II: values of rate parameters and results of simulation experiments

The reaction course of the sodium hydroxidecatalyzed hydroxymethylation of phenol was analyzed by use of high-performance liquid chromatography (HPLC), and the rate constants for the seven reactions taking place consecutively and competitively were evaluated by means of a computer simulation technique. Calibration was done at the quantification of the six phenolic monomers from the peak areas in the HPLC chromatogram, taking the differences in molar ultraviolet absorption intensities of the six compounds into account. The values of the energies of activation for the seven reactions obtained differed greatly from those reported by Eapen and Yeddanapalli. Simulation experiments carried out by use of the newly obtained rate parameters showed that the amounts of phenol left unreacted and 2,4,6-trihydroxymethylphenol in the final reaction product increased as the reaction temperature was increased and the alkali/phenol molar ratio decreased. These phenomena can be attributed to the differences in the energies of activation for the seven reactions and differences in the acid strengths of the six phenolic monomers.Part of this paper was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 and at the 1998 annual meeting of the Forest Products Society, Merida, Mexico, June 1998