Hydrolysis kinetic parameters of DP 6, 7, 8, and 9-12 fructooligosaccharides (FOS) of onion bulb tissues. effect of temperature and storage time

The objective of this study was to report on the variation of DP 6 isomers (6b, 6c + 6d1 + 6d2), 7a, 8, and 9-12 fructooligosaccharides (FOS) and their hydrolysis parameters [percent hydrolysis, consumption rate, hydrolysis rate constant (k(obsd)), and half-life time (t(1/2))] in onion bulb tissues stored for 6 months at 10, 15, or 20 degrees C. The hydrolysis of DP 6 isomers, 7a, and 8 ranged from 74 to 85%, whereas that of DP 9-12 averaged 86%. The consumption rate of 6b, 6c + 6d1 + 6d2, 7a, 8, and -12 averaged 25, 58, 38, 26, and 48 microg/g of fresh weight per week, respectively. The k(obsd) showed large variation from 53 x 10(-3) week(-1) (lowest value) to 92 x 10(-3) week(-1) (highest value), whereas the half-life t(1/2) of the different FOS ranged between 7.5 and 13.1 weeks. DP 6b isomers increased during the first month, and then the content decreased sharply during the second month at 20 degrees C but remained stable during the last 4 months, whereas at 10 and 15 degrees C, 6b decreased progressively from the first to the six month. In contrast, DP 6c + 6d1 + 6d2 decreased abruptly within the first 3 months at 10, 15, and 20 degrees C; however, during the last 3 months they remained stable, ranging between 0.32 and 0.39. Variation of DP 7a, 8, and 9-12 FOS was close to that of DP 6 FOS isomers. DP 7a increased slightly during the first month, and afterward 7a started decreasing progressively during the last 5 months. DP 8 FOS showed a similar pattern independent of temperature regime: they increased slightly within the first month, but from the second month, DP 8 began decreasing progressively and continued decreasing to the sixth month. DP 9-12 FOS also varied similarly to DP 6c + 6d1 + 6d2. They decreased sharply within the first 2 months, and during the last 4 months, they continued to decrease slowly. Surprisingly, these variations occurred independently of temperature regimes and were affected only by storage duration. It was concluded that highly polymerized FOS are preferably hydrolyzed rather than low DP FOS isomers because they have a relatively high content of fructosyl end chains.     

Colorimetric assay for the quantification of serum iodixanol concentration and its application on estimation of glomerular filtration rate in cattle

A colorimetric assay used to quantify the non-ionic contrast medium iodixanol in sera was validated and compared with high-performance liquid chromatography. The application of this assay to estimate glomerular filtration rates (GFR) in cattle was examined. Serum iodixanol was de-iodinated by alkaline hydrolysis and the amount of released iodine was subsequently determined using a ceric arsenite method. There was a close correlation between the two methods using identical specimens. In clinically healthy cattle with different body weights, the reference value (166.3-178.8 mL/min/m(2)) based on body surface area was fairly stable as compared with that (2.13-3.63 mL/min/kg) based on body weight. Based on GFR data in healthy and renal-impaired cattle, when the GFR decreased to more than 60% of the reference value, serum urea nitrogen and creatinine concentrations increased. The colorimetric assay is a simple method for the estimation of GFR in cattle and requires no expensive equipment.     

Variation in seed production among years and among individuals in 11 broadleaf tree species in northern Japan

Seed production is the most problematic part of tree regeneration and is the least amenable to control by silvicultural management. Understanding variability in seed production among years and among trees will allow better planning of seed collection for seedling production and natural regeneration. We estimated the extent of variability in seed production among years and within years among individual trees. Specifically, we measured individual annual seed production in 11 woody species in Hokkaido, northern Japan. We analyzed the coefficient of variation (CV) of seed production among years and among individual trees. We used population- and individual-based CVs (CV_pt and ) to estimate the variability in seed production among individual trees. Alnus hirsuta, in which these CVs among trees were maximal, will require further analyses of the spatial patterns of seed production among individual trees. Additionally, we used population- and individual-based CVs (CV_py and ) to estimate the variability in seed production among years. The was statistically higher than in 2 of the 11 species: Betula maximowicziana and Sorbus alnifolia. Activities for the regeneration of these species should regard the annual variation in seed production as more important than individual variation. For the nine species in which was similar to even if seed production by specific trees was not sufficient for regeneration in a particular year, other trees or stands often had high seed production in that year. We discuss the relative importance of annual and individual variability in determining efficient methods for artificial and natural regeneration of these woody plant species.     

Airborne basidiospores as an inoculum source of <Emphasis Type="Italic">Typhula variabilis</Emphasis> and the effect of hilling on the incidence of Typhula winter rot of carrots

Typhula winter rot on overwintering carrots caused by Typhula variabilis is a newly confirmed disease, and no practical control measure is yet available. To develop a control method, here we researched the infection period of T. variabilis and the time that winter rot appeared on carrots. Using spore traps, we found that basidiospore rain occurred from September to November before snowfall in Memuro, Hokkaido. In addition, carrot leaves collected in autumn had already been infected by T. variabilis. These epidemiological investigations revealed that the pathogen releases basidiospores to infect carrot leaves before snow cover, resulting in root decay under snow. An effective control method was then developed to avoid direct contact of basidiospores of T. variabilis with plant tops by covering the plants with soil in autumn. Thus, the percentage of rotted roots was reduced to about half.     

Effect of exposure to low salinity water on plasma ion regulation and survival rates in artificially wounded devil stinger <Emphasis Type="Italic">Inimicus japonicus</Emphasis>

We investigated the effect of exposure to low salinity water on plasma ion regulation and survival rates in artificially wounded devil stinger Inimicus japonicus. All fishes survived in 33% seawater (SW), while survival rate in 100% SW was 5.1% at 24 h. In 100% SW, plasma Na⁺, K⁺, Mg²⁺, and Ca²⁺ concentrations significantly increased to 238?±?49.9, 9.6?±?2.4, 15.1?±?3.5 and 5.0?±?0.7 mmol/l at 6 h, respectively; the gill Na⁺/K⁺–ATPase (NKA) activity was almost stable, although only one fish survived to 24 h. In 33% SW, plasma Na⁺ and K⁺ concentrations remained at the same level, and plasma Mg²⁺ and Ca²⁺ concentrations gradually increased to 16.2?±?0.7 and 4.5?±?0.2 mmol/l until 24 h, respectively. The NKA activity significantly increased to 5.1?±?1.1 µmol ADP/mg protein per h at 6 h. A positive correlation was observed between the wound surface area against body weight and the plasma ion concentrations, although no difference was observed in the restoration rate of the wounded area between 100 and 33% SW. These results indicate that exposure of wounded fish to low salinity water improves survivability by favoring plasma ion regulation without influencing the restoration rate.     

Mapping a gene conferring resistance to <Emphasis Type="Italic">Wheat yellow mosaic virus</Emphasis> in European winter wheat cultivar ‘Ibis’ (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Wheat yellow mosaic, caused by Wheat yellow mosaic virus (WYMV), is one of the most devastating soil-borne diseases of winter wheat (Triticum aestivum L.) in Japan. Yellow-striped leaves and stunted spring growth, symptomatic of WYMV infection, result in severe yield loss. A new putative WYMV resistance gene in the European wheat cultivar ‘Ibis’ was mapped in the cluster of microsatellite markers including Xcfd16, Xwmc41, Xcfd168 and Xwmc181 on the long arm of chromosome 2D at the distances of 2.0 cM, 4.0 cM, 7.1 cM and 12.4 cM, respectively. WYMV-resistant cultivars contained a common haplotype of the four markers, whereas moderately susceptible and susceptible cultivars did not. These results should be useful in marker-assisted selection for WYMV resistance in wheat.     

Seasonal variation of paulownia witches’-broom phytoplasma in paulownia trees and distribution of the disease in the Tohoku district of Japan

Seasonal variation of paulownia witches’-broom (PWB) phytoplasma within different organs (leaves, branch and trunk bark and roots) in paulownia trees was investigated by the amplification of a PWB-specific DNA fragment by the polymerase chain reaction (PCR). In leaf samples, PWB phytoplasma was first detected in June and the incidence gradually increased. On the other hand, the PWB was detected at relatively low incidence in branch bark, trunk bark and roots and the incidence did not change among seasons. A survey of PWB in 27 fields in the Tohoku district of Japan showed that malformed flower buds were observed in paulownia trees in almost all of the fields. PWB-phytoplasma was also detected by PCR from paulownia trees in almost all of the fields in Iwate and Fukushima Prefectures. The frequencies of trees in which phytoplasma was detected by PCR were higher than those in which symptoms were observed. These results indicated that PCR amplification of a PWB-specific DNA fragment is an effective tool for practical diagnose and that PWB is widely distributed in the Tohoku district of Japan.     

Changes in the plasma levels of several bone markers in newborn calves during the first two days of life

The fluctuations in the plasma levels of several bone markers were investigated in newborn calves. Experiment 1 monitored the postnatal changes in the plasma levels of tartrate-resistant acid phosphatase isoform 5b (TRAP5b), total alkaline phosphatase (t-ALP) and bone-specific alkaline phosphatase (BAP) in four calves. These markers increased significantly from 9−20 hr after the first colostrum-suckling compared with the values immediately after birth. Experiment 2 evaluated changes in the plasma TRAP5b, t-ALP, BAP and type I collagen cross-linked N-telopeptide (NTx) levels within 2 days post-birth in five calves with successful passive immunization via colostrum (non-deficient group) and five others with poor colostrum intake (deficient group). The non-deficient group had significantly higher plasma levels of the four parameters around 12 hr of life compared with the deficient group. The results suggest that the increase in plasma bone markers in calves in the first day of life is related to the colostrum intake.