Effects of row deep tillage for the growth base formed by piling up soil in damp lowlands behind coastal sand dunes to construct coastal disaster prevention forest belts on the Kujukuri coastline,Japan

ABSTRACT

To successfully afforest coastal forest belts ensuring high disaster prevention, growth bases for them have been constructed by piling up soil in the low wetlands along the Kujukuri coastline. Ground surfaces in such bases are often covered with water because of soil compaction, leaving them susceptible to stagnant water. Water stagnation in soil is problematic, potentially interfering with afforesting coastal forests. Therefore, row deep tillage was conducted for parts of growth bases to combat the poor physical properties of the existing soil. Here, we surveyed soil profiles and measured vertical soil hardness distribution in two forest stands with piling up soil to evaluate the effectiveness of tillage for man-made soil. Soil hardness measurements indicated that the vertical areas with ‘soft’ and ‘hard/consolidated’ soil alternately appeared in growth base profiles. Generally, soil of the dense and very hard layers was apt to be formed by strong compaction of the filled-up soil because of heavy machinery usage during growth base preparation. Such dense and hard soils in the untilled areas of the profiles were also observed in this study. By contrast, it was confirmed that row deep tillage drastically improved soil physical properties, i.e., decreased hardness and increased water permeability, because the sequential hardened subsoil layers were well-broken-up. Moreover, it was observed many thick and large roots penetrated deeper layers with deep tillage areas. These results suggest that row deep tillage of hardened soil is quite effective at securing the areas and providing the physical conditions for deeply penetrated roots into deeper soils, which increases healthy root development. They show the effects of soil hardness reduction and water permeability improvement have been maintained for two decades, at least, after construction. These findings will be useful for alleviating some problems of soil compaction, water stagnation, and tree-growth hindrance that have been encountered on afforestation sites with man-made soil.     

Genotyping of the <Emphasis Type="Italic">SiDREB2</Emphasis> gene in worldwide foxtail millet (<Emphasis Type="Italic">Setaria italica</Emphasis> (L.) P. Beauv.) genetic resources with special attention to Indian landraces

We genotyped Setaria italica Dehydration-responsive element-binding 2 (SiDREB2) gene, which had been reported to be associated with dehydration stress tolerance, in 588 accessions of foxtail millet from various parts of Eurasia and other regions by a dCAPS marker. Of these, 480 accessions were genotyped in ribosomal DNA (rDNA), polyphenol oxidase (PPO) gene and Heading date 1 (HD1) gene in our previous studies, and 108 accessions from India were newly used in this study and genotyped in these genes in addition to the SiDREB2 gene. We compared the geographical distribution of the SiDREB2 genotypes with that of these three genes. Accessions from countries in South Asia including India and Sri Lanka were the most variable in the SiDREB2 gene followed by Korean accessions and Japanese accessions, suggesting that Indian accessions and East Asian accessions are useful as genetic resources for dehydration stress tolerance. This study also showed that although Indian accessions are not so diverse in rDNA and in transposon display markers previously studied, they are diverse in adaptive genes such as SiDREB2, PPO and HD1 genes.     

IMAGING DIAGNOSIS—ECTOPIC SPLEEN MIMICKING HEPATIC TUMOR WITH INTRA‐ABDOMINAL METASTASES INVESTIGATED VIA TRIPLE‐PHASE HELICAL COMPUTED TOMOGRAPHY IN A DOG

A 10‐year‐old castrated male miniature dachshund was presented with an abdominal mass. The dog had a history of splenectomy. Triple‐phase helical computed tomography was utilized, revealing a hepatic mass and multiple intra‐abdominal solid masses. In triple‐phase helical computed tomography the images, hepatic mass and two of four intra‐abdominal masses were heterogenous in all phases. Therefore, we diagnosed a malignant hepatic tumor and presumed intra‐abdominal metastases. The masses were surgically removed and were histologically composed of normal spleen tissues, findings which were consistent with ectopic spleen.     

Effect of supplemented sericin on the development,cell number,cryosurvival and number of lipid droplets in cultured bovine embryos

Sericin was investigated as an alternative to fetal bovine serum (FBS) for bovine embryo culture. In vitro matured oocytes were developed using 0.05%, 0.1% or 0.15% sericin. The developmental rate, cryosurvival rate and blastulation time of these embryos were compared with those of embryos developed using 5% FBS. The number of lipid droplets was compared among the blastocysts developed using 5% FBS, using 0.05% sericin and in vivo. The rate of cleavage and blastocyst formation was similar among all groups. Blastulation occurred significantly earlier in the embryos developed using 5% FBS than in those developed using sericin at any concentration (P < 0.05). At 72 h after thawing, the cryosurvival rate of the blastocysts developed using 5% FBS and 0.05% sericin were significantly higher compared with those developed using 0.1% and 0.15% sericin (P < 0.05). The blastocysts developed using 0.05% sericin and in vivo produced a significantly fewer number of medium and large lipid droplets than those developed using 5% FBS. These results suggest that the blastocysts developed using 0.05% sericin show characteristics similar to those of the blastocysts developed in vivo and that the use of sericin as an alternative to FBS is feasible.     

In vitro safety assessments and antimicrobial activities of Lactobacillus rhamnosus strains isolated from a fermented mare's milk

Safety and probiotic characteristics such as antimicrobial activities of three Lactobacillus rhamnosus strains, FSMM15, FSMM22 and FSMM26, previously isolated as potential probiotics from fermented mare's milk were investigated. The three FSMM strains were susceptible to ampicillin, gentamycin, kanamycin, streptomycin, tetracycline and chloramphenicol, whereas they were resistant to erythromycin (minimal inhibitory concentration (MIC) = 4?8 µg/mL) and clindamycin (MIC = 4 µg/mL); bioconversion of bile salts, hemolytic activity and mucin degradation activity were negative; enzymatic activities of α‐chymotrypsin and β‐glucosidase were detected, but those of α‐galactosidase, β‐glucuronidase and N‐acetyl‐β‐glucosaminidase, were undetectable. Among the strains, strain FSMM15 was chosen as a safer probiotic candidate due mainly to the lack of plasminogen binding ability. Despite lower acid production of strain FSMM15 than others, its cell‐free culture supernatant inhibited growths of Salmonella Typhimurium LT‐2, Shigella sonnei , Listeria monocytogenes , and Escherichia coli O157 with comparable levels of ampicillin, suggesting a favorable aspect of strain FSMM15 as a probiotic strain.     

In situ observation of pinewood nematode in wood

In pine wilt disease, xylem dysfunction occurs in relation to nematode migration and proliferation in host tissue, but the detection accuracy of pinewood nematode (PWN), Bursaphelenchus xylophilus, in pine stem tissue remains unclear. This study describes the use of cryo-scanning electron microscopy (cryo-SEM) and fluorescein-conjugated wheat germ agglutinin (F-WGA) staining to detect PWN. After PWN invasion, the frequency of surface fluorescence in PWN increased in pine stems from the day of inoculation to 3 weeks after inoculation. However, the fluorescence frequency decreased significantly during the advanced disease stage after 5 weeks. Thus, detecting PWN based on fluorescent staining of the nematode body surface coat protein can be misleading when used to examine the correlation between the development of disease symptoms and the nematode population. In contrast, all cut body segments were fluorescent, and their fluorescent components were common in pine-stem cross sections, regardless of the timing after inoculation. In addition, PWN were observed under cryo-SEM only in empty resin canals and this distribution was confirmed by F-WGA staining of PWN cut in a cross section. Thus, PWN detection based on fluorescent staining of surface coat proteins by F-WGA was not reliable in longitudinal sections of pine stems because of changes in nematode stainability during disease progression. To detect PWN in infected plants, we concluded that a combination of both methods is most effective.     

Taxonomic characterization of Pyricularia isolates from green foxtail and giant foxtail, wild foxtails in Japan

Twenty-eight Pyricularia isolates from two wild foxtails—green foxtail (Setaria viridis) and giant foxtail (S. faberii)—in Japan were taxonomically characterized by DNA analyses, mating tests, and pathogenicity assays. Although most of the isolates failed to produce perithecia in mating tests with Magnaporthe oryzae, a diagnostic polymerase chain reaction-restriction fragment length polymorphism phenotype of M. oryzae was detected in the beta-tubulin genomic region in all isolates. The pathogenicity assays revealed that host ranges of the isolates were similar to those of isolates from foxtail millet (S. italica), which were exclusively pathogenic on foxtail millet. In addition to the 28 isolates from wild foxtails, 22 Pyricularia isolates from 11 other grasses were analyzed by RFLP using single-copy sequences as probes. In a dendrogram constructed from the RFLP data, isolates that were previously identified as M. oryzae formed a single cluster. All the wild foxtail isolates formed a subcluster with foxtail millet isolates within the M. oryzae cluster. From these results, we conclude that Pyricularia isolates from the wild foxtails are closely related to isolates from foxtail millet and should be classified into the Setaria pathotype of M. oryzae.     

Hepatoprotective action of dietary bluefin tuna skin proteins on CCl4-intoxicated mice

We have shown that dietary bluefin tuna skin (TUS) protects against carbon tetrachloride (CCl₄)-induced hepatic damage in mice. The CCl₄-induced necrotic area was decreased in mice fed a TUS-containing diet. Consistent with the decreased necrotic area, dietary TUS markedly lowered the elevated serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and the thiobarbituric acid-reactive substance (TBARS) formation induced by CCl₄ injection. TUS diets also decreased phosphorylation of inhibitory kappa B-?? and blocked the translocation of nuclear factor-kappa B to the nucleus. TUS is composed mainly (80.7?%) of type I collagen, and our results revealed that dietary tuna collagen peptides (TUCP) attenuated the increased hepatic necrotic area, serum AST and ALT activities, and liver TBARS levels induced by CCl₄, similar to TUS, thus enabling us to attribute the hepatoprotective action of TUS in CCl₄-intoxicated mice to tuna collagen. Therefore, TUS and TUCP may be potential food resources that are capable of alleviating hepatitis symptoms.     

Experimental infection of calves with Pasteurella multocida Serovar A: 3 isolated in Japan

Pasteurella multocida, serovar A: 3, selected by pathogenicity in mice from among 10 strains isolated from pneumonic lesions of calves, was adjusted to 10(7), 10(8) and 10(10) colony-forming units (CFU), and inoculated intratracheally into four calves. All calves showed pyrexia and had lungs with congestion and hepatization. Inoculation with 10(10) CFU of bacteria produced respiratory symptoms and abscesses in lungs. This information will aid elucidation of the pathogenicity of P. multocida and the development of vaccines.