Transfer of the Rsv3 locus from ‘Harosoy’ for resistance to soybean mosaic virus strains C and D in Japan

Resistance to soybean mosaic virus (SMV) is imperative for soybean (Glycine max (L.) Merr.) production in the Tohoku region. Molecular markers for SMV resistance were previously reported for U.S. SMV strains, but they cannot be applied because of the differences in strain classification between Japan and the U.S. A U.S. variety ‘Harosoy’ has been used mainly as a donor of resistance to SMV strains C and D in a Japanese breeding program, resulting in resistant varieties such as ‘Fukuibuki.’ Because ‘Harosoy’ harbors the Rsv3 gene conferring resistance to the virulent SMV strain groups, G5 through G7, it appears that the Rsv3 gene confers resistance to strains C and D. In this study, we introduced resistance to the two strains from ‘Fukuibuki’ into a leading variety ‘Ohsuzu’ by recurrent backcrossing with marker-assisted selection. All lines selected with markers near Rsv3 showed resistance to the strains, suggesting that the Rsv3 locus is responsible for the resistance. Three years of trials showed that one of the breeding lines, ‘Tohoku 169,’ was equivalent to ‘Ohsuzu’ with respect to agricultural characteristics such as seed size, maturity date, and seed yield, except for the SMV resistance.     

Relationship between production of hydroxyl radicals and degradation of wood, crystalline cellulose, and a lignin-related compound or accumulation of oxalic acid in cultures of brown-rot fungi

The degradation of wood, filter paper cellulose, and a lignin-substructure model, was measured in cultures of seven fungi usually regarded as brown-rot fungi. Hydroxyl radical production and the accumulation of oxalic acid in the cultures were also measured. Four of the fungi, Gloeophyllum trabeum, Tyromyces palustris, Laetiporus sulphureus, and Postia placenta, were typical brown-rot fungi, in that they preferentially degraded and eliminated the polysaccharides in wood and produced large amounts of hydroxyl radical. The rates of hydroxyl radical generation in cultures of the four fungi were directly proportional to the degradation rates of wood, cellulose, and the lignin-related compound, and inversely proportional to the amount of oxalic acid in the cultures. Two of the fungi, Daedalea dickinsii and Lentinus lepideus, did not degrade any of the substrates significantly and produced very little hydroxyl radical. Coniophora puteana had the highest rate of cellulose degradation, but did not degrade wood or the lignin model significantly and produced only negligible amounts of hydroxyl radical. These results indicate that brown-rot fungi produce large amounts of hydroxyl radical for the degradation of wood and crystalline cellulose.     

Changes in the relationship between tree size and aboveground respiration in field-grown hinoki cypress (Chamaecyparis obtusa) trees over three years

Respiration measurements of aerial parts of 18-year-old hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) trees were made under field conditions over three years to study changing relationships with tree age between respiration and phytomass, phytomass increment, and leaf mass. The relationship between annual respiration (r(a)) and phytomass (w(T)) was approximated by a proportional function (r(a) = aw(T)), where the proportional constant (a) decreased year by year. The effect of time on the relationship between annual respiration and phytomass of each sample tree was fitted by a power function. Respiration of the tree suppressed by the canopy decreased year by year, but respiration of the other trees increased slightly with age. The relationship between annual respiration and leaf mass was also approximated by a generalized power function. Excluding the suppressed tree, the relationship between annual respiration (r(a)) and the annual increment of aboveground phytomass (Deltaw(T)) was described by a proportional function (r(a) = 2.27Deltaw(T)), where the proportional constant, 2.27, was independent of sample tree and year, indicating that about 2.3 times of the annual aboveground phytomass increment equivalent was respired annually. For any tree, the time constant relationships between annual respiration and leaf mass and phytomass increment for different-sized trees were similar to the corresponding time continuum relationships. In contrast, the time continuum relationship between annual respiration and phytomass differed from the time constant relationship, indicating that respiration of less active woody tissue contributed significantly to aboveground respiration. Based on the relationship between tree size and annual respiration, annual aboveground stand respiration was estimated to be 25.0, 26.9, and 25.8 Mg(dm) ha(-1) year(-1) for the three consecutive years, respectively, and the corresponding aboveground stand biomass was 60.0, 69.0, and 76.8 Mg(dm) ha(-1).     

Lateral resistance of anchor-bolt joints between timber sills and foundations III: numerical simulations of the effect of sill thickness on the effective lateral resistance of multiple anchor-bolt joints

Effective lateral resistance of multiple anchorbolt joints was estimated by considering sill thickness or length/diameter ratios of anchor bolts. Load-slip relationships of single anchor bolt joints were analyzed by the stepwise linear approximation based on the generalized theory of a beam on an elastic foundation and the criterion of “fracture bearing displacement” for several sill thicknesses or length/diameter ratios of anchor bolts. Monte Carlo simulations of the effective lateral resistance of multiple anchor-bolt joints were conducted using the analyzed load-slip curves of single anchor-bolt joints. Effective resistance ratios of multiple anchor-bolt joints were simulated for some combinations of length/diameter ratios of anchor bolts, lead-hole clearances, and number of anchor bolts. The simulated results are: (1) the influence of lead-hole clearance becomes more apparent as length/diameter ratios of single anchor-bolt joints decrease; (2) there is no obvious effect of number of anchor-bolts over the range of 5 to 15; (3) average effective resistance ratios can be adopted for allowable stress design; and (4) reduction of effective resistance ratios should be considered particularly for small length/diameter ratios of anchor-bolt joints.     

Growth, nitrogen fixation and mineral acquisition of Alnus sieboldiana after inoculation of Frankia together with Gigaspora margarita and Pseudomonas putida

The role of tetrapartite associations among Frankia, Gigaspora margarita (an arbuscular mycorrhizal fungus), Pseudomonas putida (rhizobacterium), and Alnus sieboldiana in growth, nitrogen fixation, and mineral acquisition of A. sieboldiana was investigated. Seedlings of A. sieboldiana were inoculated with Frankia isolated from root nodules of alder, followed by inoculation of G. margarita and P. putida, and were grown for 5 months in a greenhouse. The seedlings inoculated with Frankia and G. margarita together produced the highest biomass of shoots and root nodules. Nitrogen-fixation activity, measured by acetylene reduction assay, was observed when Frankia was inoculated. The activity, on a per-nodule gram basis, decreased after G. margarita inoculation, but on a per-plant basis there was no significant difference in the activity among inoculation treatments. The mineral content in the seedlings changed after inoculation with Frankia, but not after inoculation with P. putida and/or G. margarita. The results showed a synergistic interaction among Frankia, the mycorrhizal fungus, and the rhizobacterium on the growth of A. sieboldiana.     

Relationships of stem surface area to other stem dimensions for Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis> D. Don) and Japanese cypress (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis> Endl.) trees

I investigated the relationships between stem surface area outside bark and other stem dimensions for Japanese cedar (Cryptomeria japonica D. Don) and Japanese cypress (Chamaecyparis obtusa Endl.) trees. The stem dimensions used here were the basal area and the product of diameter at breast height (dbh) and total tree height. The regression equation of the stem surface area s against basal area g was s = 184.216g for the cedar trees and s = 156.878g for the cypress trees. The slope of the equation was significantly different between the two species. For the same dbh, the cedar trees tended to have a higher total tree height than the cypress trees. The cedar trees also had a larger surface area of relative stem form than the cypress trees. These results indicated that the difference in the slope was produced by the differences in both the stem slenderness and tapering between the two species. On the other hand, the regression equation between the stem surface area and the product of dbh and total tree height dh was s = 1.937dh for the cedar trees and s = 1.921dh for the cypress trees, whereas no significant difference in the slope was found. The obtained slopes for the cedar and cypress trees seemed to be in accord with that for other coniferous species reported in earlier studies, suggesting that the variation in the slope among coniferous species would be small. The estimation from the basal area would provide a simpler means for estimating the stem surface area and would be useful in obtaining an approximation of the surface area. By contrast, the estimation from the product of dbh and total tree height would provide a more accurate and precise estimate as well as a wider applicable range, i.e., a parameter for physiological growth models. In conclusion, it could not be judged which regression equation examined in the present study was superior to the other, and thus it was important to select an appropriate equation depending both on the purpose and on the time and labor available.     

The nutrient translocation of seedlings with chemical analyses of the xylem saps ofCryptomeria japonica D. Don andPinus densiflora Sieb. et Zucc.

The chemical compositions of xylem saps ofCryptomeria japonica D. Don andPinus densiflora Sieb. et Zucc. were studied. One-year-old seedlings of these species were transplanted into hydroponics in the middle of June. Some seedlings were retained in the nursery. Two nitrogen sources, ammonium and nitrate nitrogen, were applied separately. The samplings of xylem saps were made at the end of July. Saps were collected from both roots and tops of the seedlings using a pressure chamber. InC. japonica, the fact that the translocation form of nitrogen from the roots to shoots mainly was citrulline was confirmed. The result ofP. densiflora in this study showed that glutamine was the predominant compound of nitrogen translocation. Total nitrogen ofP. densiflora had a large value in the series of ammonium. Glutamine increased in the ammonium series of both species. Nitrate nitrogen was found in whole samples ofC. japonica, and was not found inP. densiflora. As the result of cations in the saps, monovalent cations were rich inP. densiflora, and divalent cation concentrations were greater inC. japonica. The idea that the great oxygen requirement ofP. densiflora produces the negative charge gives an explanation of the great retention of divalent cations in the roots. The idea that the mineral distribution indicates root activity related to its negative charge production also is considered a possibility.     

In vivo anti-influenza virus activity of an immunomodulatory acidic polysaccharide isolated from Cordyceps militaris grown on germinated soybeans

An acidic polysaccharide (APS) was isolated from the extract of Cordyceps militaris grown on germinated soybeans. Analyses of sugar composition indicated that APS consisted of d-galactose, L-arabinose, D-xylose, L-rhamnose, and D-galacturonic acid. On the basis of the result of methylation analysis, APS was considered to be mainly composed of Araf-(1-->, -->5)-Araf-(1-->, -->4)-Galp-(1--> and -->4)-GalAp-(1--> residues. When the polysaccharide was intranasally administered, it decreased virus titers in the bronchoalveolar lavage fluid and the lung of mice infected with influenza A virus and increased survival rate. Furthermore, APS increased TNF-alpha and IFN-gamma levels in mice when compared with those of untreated mice. APS enhanced nitric oxide (NO) production and induced iNOS mRNA and protein expressions in RAW 264.7 murine macrophage cells. The induction of mRNA expression of cytokines including IL-1beta, IL-6, IL-10, and TNF-alpha was also observed. These results demonstrated that APS might have beneficial therapeutic effects on influenza A virus infection at least in part by modulation of the immune function of macrophages.     

The histopathogenesis of paralytic rabies in six-week-old C57BL/6J mice following inoculation of the CVS-11 strain into the right triceps surae muscle

A fatal encephalomyelitis was developed after intracerebral and hind limb inoculation of in 6-week-old C57BL/6J mice by the inoculation of fixed rabies virus (CVS-11 strain), intracerebrally and into hind. After the intracerebral inoculation, virus antigens were detected in the cerebral cortex and hippocampus at 2 days postinoculation (PI), and later spread centrifugally to thalamus, brain stem, cerebellum, spinal cord and spinal ganglia. At 4 days PI, severe apoptosis and DNA fragmentation were observed in the hippocampus and cerebral cortex. All mice infected intracerebrally were dead without limb paralysis at from 10 to 11 days PI. In contrast, mice infected with virus intramuscularly were persistently observed virus antigens in the myocytes at the site of inoculation from 2 days PI. At 4 days PI, the antigens were demonstrated in the spinal dorsal root ganglia, spinal cord and muscle spindles without their detection in the cerebrum and hippocampus. There were no apoptosis in the spinal cord and dorsal root ganglia, however hind limb paralysis was found in all infected mice. Hind limb paralysis was progressed to quadriparalysis, and mice were dead from 11 to 13 days PI. From 4 days PI, necrosis of neuron was observed in the the spinal and dorsal ganglia with infiltration of lymphocyte. This study suggested that the necrosis of spinal neurons was more important to cause the paralysis of hind limb rather than the severe cerebral infection and apoptosis in C57BL/6J mice infected with CVS-11 strain. The virus primarily replicated in the muscles was ascended the spinal cord via afferent fibers and retrogradely invaded the cerebrum, and with subsequent spread to muscle spindles.