Quantitative trait loci responsible for the difference in γ-oryzanol content in brown rice between japonica-type and indica-type rice cultivars

γ-Oryzanol is a main oleophilic component in rice bran oil and has been well recognized as a good dietary supplement for human health, as well as having uses in industrial materials. japonica-type rice cultivars generally showed significantly higher contents of total γ-oryzanol in brown rice compared with indica-type cultivars, although within-group variation was significant. The objective of this study was to explore quantitative trait loci (QTLs) responsible for the difference in the γ-oryzanol content between japonica-type and indica-type rice cultivars, using recombinant inbred lines (RILs), backcross inbred lines (BILs), and corresponding chromosome segment substitution lines (CSSLs) derived from crosses between japonica-type and indica-type. Results from RILs and BILs showed that eight QTLs were detected with R² from .09 to .16. Nine candidate regions for QTL were also suggested from corresponding CSSLs. These QTLs from RILs and BILs and the candidate regions from CSSLs were not overlapped, although one QTLs was mapped near the boundaries of the respective candidate region. At four QTLs and three candidate regions, alleles or segments from japonica-type caused higher contents than those from indica-type. On the other hand, at the other four QTLs and six candidate regions, alleles or segments from indica-type caused higher contents than those from japonica-type, which is a reverse result to the parental differences. This result strongly suggested that alleles with increasing effects on γ-oryzanol content could be accumulated not only from japonica-type but also from indica-type, leading to a potential for increase in γ-oryzanol content in future breeding programs.     

A Computer Program for Automatic Watering Based on Potential Evapotranspiration by Penman Method and Predicted Leaf Area in Miniature Pot Rose Production

In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multiple linear regression equation of leaf area and Penman Method. The experiments were carried out for a year in two watering experimental plots, one of which was controlled by pF value, and the other by the computer program. After comparing the results of the two plots, the following findings were obtained. In the computer program plot, the observed and predicted values of both leaf area and evapotranspiration indicated significant correlation at the 1% level, which suggested that the computer program had high prediction accuracy. In addition, no significant difference was observed between the two experimental plots with respects to the plant height, plant diameter, leaf area, leaf number, fresh weight, and dry weight, which demonstrated that the plants in the computer program plot had normal growth. On the other hand, although the number of flower buds and flowering shoots showed higher values at the end of certain cultivations in the computer program plot than those in pF value plot, we proposed that it was due to the effect of cumulative daily solar radiation in the greenhouse, rather than the watering. Thus, we have reached the conclusion that the computer program for automatic prediction of watering time point developed by this study has high applicability in miniature pot rose production.     

Heterogeneity of Hanganutziu-Deicher antigen glycoproteins in different species animal sera.

A heterophilic Hanganutziu-Deicher (HD) antigen is present in many animal sera except human and chicken sera. To visualize the antigenic molecules, nine species animal and human sera were analyzed by SDS-PAGE, followed by Western blotting and immunostaining with avain anti-N-glycolylneuraminyl-lactosyl ceramide antibody which recognizes the terminal N-glycolylneuraminic acid moiety of glycoconjugates as an epitope of the HD antigen. Several HD antigen-active glycoprotein bands were detected in the sera of fetal calf, calf, horse, goat, monkey, rabbit, guinea pig, rat and mouse, except for human serum. The HD antigenic proteins showed heterogeneities in their molecular weights and were not identical with any major band visualized with silver-staining, indicating that they are minor components of serum proteins in each animal. Neuraminidase treatment destroyed the antigenicity of all proteins, confirming that N-glycolylneuraminic acid (NeuGc) at the non-reducing terminal of carbohydrate chains is the antigenic epitope in serum glycoprotein molecules as already confirmed in glycosphingolipid (GSL) antigens. The finding of HD-antigenic glycoproteins in animal sera suggests that they also stimulate HD antibody production in patients who received animal antiserum for therapeutic aim.     

Diversity in nicotinamide-adenine dinucleotide requirement for the growth of different strains of Mycoplasma synoviae

The type strain WVU 1853 and field strains SG, N26 and A642 of Mycoplasma synoviae were examined for their requirement for nicotinamide-adenine dinucleotide (NAD) for in vitro growth. All the strains grew and could be repeatedly passaged in Frey broth medium supplemented with filter-sterilised NAD. In modified Frey broth medium from which NAD was omitted and broth medium for which the supplements including yeast extract and NAD were autoclaved, only strains N26 and A642 could be grown and passaged. The growth curves of strain N26 determined in broth media with and without NAD were similar. These results indicated that there are differences in NAD-requirement for in vitro growth among strains of M synoviae.     

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.     

Development and evaluation of microsatellite loci for <Emphasis Type="Italic">Gynochthodes boninensis</Emphasis> (Rubiaceae), a woody climbing plant endemic to the Bonin (Ogasawara) Islands,Japan

Microsatellite loci were developed for Gynochthodes boninensis, an endemic climbing plant in the Bonin Islands. Using a Roche 454 GS Junior next-generation sequencer, 158 microsatellite loci were designed. Of the 48 microsatellite loci tested, 37 were successfully amplified and 25 were polymorphic in two populations of G. boninensis. For the 25 polymorphic loci, the mean expected heterozygosities per locus were 0.303 in the Chichijima Island population and 0.310 in the Hahajima Island population, respectively. There was no evidence of linkage disequilibrium in either population, but one locus showed significant deviation from Hardy–Weinberg equilibrium in one population. The microsatellite loci developed in this study will be useful for future studies of population genetics of G. boninensis. In particular, because this species is androdioecious (males and hermaphrodites coexist), characterizing the species gene flow is crucial to understanding the evolution and maintenance of this rare sexual system.     

Differences in nitrogen economy of temperate trees

Twenty-four temperate tree species were classified into three groups based on cluster analysis of relative growth rate, nitrogen concentration, nitrogen-production efficiency, nitrogen-distribution ratio and nitrogen-use efficiency as follows: Group I (Asteridae and Rosidae), Group II (Dilleniidae and Hamamelidae) and Group III (Coniferopsidae). Relative growth rate (RGR) was high in Group II, moderate in Group I and low in Group III. The regression coefficient for the relationship between RGR and leaf nitrogen concentration was higher in Group II than in Group I, and no relationship was observed in Group III. Parameter analysis of RGR indicated that RGR per unit leaf nitrogen was important for all three groups, but that the allocation of nitrogen to leaves was particularly important in Groups I and II. The ratio of dark respiratory rate (R) to net photosynthetic rate (A) was higher in Group I than in Group II. Neither A nor R was measured in the Group III species. A linear relationship was observed between leaf nitrogen concentration and A in Group II, but this relationship was not evident in Group I.     

Vertical, horizontal and azimuthal variations in leaf photosynthetic characteristics within a Fagus crenata crown in relation to light acclimation

An understanding of spatial variations in gas exchange parameters in relation to the light environment is crucial for modeling canopy photosynthesis. We measured vertical, horizontal and azimuthal (north and south) variations in photosynthetic capacity (i.e., the maximum rate of carboxylation: Vcmax), nitrogen content (N), leaf mass per area (LMA) and chlorophyll content (Chl) in relation to relative photosynthetic photon flux (rPPF) within a Fagus crenata Blume crown. The horizontal gradient of rPPF was similar in magnitude to the vertical gradient of rPPF from the upper to the lower crown. The rPPF in the north quadrant of the crown was slightly lower than in the south quadrant. Nitrogen content per area (Narea), LMA and Vcmax were strictly proportional to rPPF, irrespective of the vertical direction, horizontal direction and crown azimuth, whereas nitrogen content per dry mass, Chl per area and photosynthetic capacity per dry mass (Vm) were fairly constant. Statistical analyses separating vertical trends from horizontal and azimuthal trends indicated that, although horizontal and vertical light acclimation of leaf properties were similar, there were two significant azimuthal variations: (1) Vcmax was lower in north-facing leaves than in south-facing leaves for a given Narea, indicating low photosynthetic nitrogen-use efficiency (PNUE) of north-facing leaves; and (2) Vcmax was lower in north-facing leaves than in south-facing leaves for a given LMA, indicating low Vm of the north-facing leaves. With respect to the low PNUE of the north-facing leaves, there were no significant azimuthal variations in leaf CO2 conductance from the stomata to the carboxylation site. Biochemical analysis indicated that azimuthal variations in nitrogen allocation to ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and in nitrogen allocation between carboxylation (Rubisco and other Calvin cycle enzymes) and light harvesting machinery (Chl pigment-protein complexes) were not the main contributor to the difference in PNUE between north- and south-facing leaves. Lower specific activity of Rubisco may be responsible for the low PNUE of the north-facing leaves. Anatomical analysis indicated that not only high leaf density, which is compatible with a greater fraction of non-photosynthetic tissue, but also thick photosynthetic tissue contributed to the low Vm in the north-facing leaves. These azimuthal variations may need to be considered when modeling canopy photosynthesis based on the Narea-Vcmax or LMA-Vcmax relationship.     

Effects of estimation length on parameter estimates of geometric Brownian motion for log price dynamics

We investigated an effect of the estimation length of the time-series data on the parameter estimates of geometric Brownian motion for log prices. This is to examine how much the estimates vary depending upon the estimation length of the data for the simulation purpose of stochastic modeling. Using the monthly time-series data for akamatsu, sugi, and hinoki from January 1975 to December 2000, our analysis shows that the longer the estimation length, the more stable the estimated value of the drift coefficient and the volatility coefficient of geometric Brownian motion become, implying less variability in the estimates needed for the simulation analysis. On the other hand, the shorter estimation length would tend to reflect such a sudden change in the data as the oil shock or the short-term decreasing or increasing tendency, which results in the large degree of variability in parameter estimates. This stems from the fact that the long estimation length regards a short-term price changes as an intrinsic part of price volatility. These results imply that when conducting a scenario analysis under stochastic environments, for the shorter estimation length, the wider range of parameter settings should be incorporated into the analysis.