Genetic analysis of tissue culture traits in barley cv. 'Lenins'

The barley cultivar ‘Lenins’ was found to be a genotype showing high shoot regeneration ability in cultures derived from immature embryos. Five cultivars different from ‘Lenins’ in shoot regeneration ability were reciprocally crossed with ‘Lenins’ and the inheritance of tissue culture traits was investigated. F₂ plants showed continuous distributions in callus growth and percentage of shoot regeneration, suggesting that these traits were controlled by polygenes. The F₂ population, derived from a cross between ‘Lenins’ and ‘6721′, showed a monogenic segregation for the number of regenerated shoots, and the segregation ratio fitted 1:2:1. Tissue culture traits of ‘Lenins’ were controlled by several genes, whereas the number of regenerated shoots related to the efficiency of shoot regeneration is controlled by one major gene.     

Chemical studies on antioxidant mechanism of curcumin: analysis of oxidative coupling products from curcumin and linoleate

As a part of a research project on the antioxidant mechanism of natural phenolics in food components, curcumin, a turmeric antioxidant, was investigated in the presence of ethyl linoleate as one of the polyunsaturated lipids. During the antioxidation process, curcumin reacted with four types of linoleate peroxyl radicals. Six reaction products were observed in the reaction and subsequently isolated. Their structures were determined by physical techniques, revealing that they have novel tricyclic structures, including a peroxyl linkage. On the basis of the formation pathway for their chemical structures, an antioxidant mechanism of curcumin in polyunsaturated lipids was proposed, which consisted of an oxidative coupling reaction at the 3'-position of the curcumin with the lipid and a subsequent intramolecular Diels--Alder reaction.     

Adapting the Profile Model to Calculate the Critical Loads for East Asian Soils by Including Volcanic Glass Weathering and Alternative Aluminum Solubility System

Adaptation of the steady-state soil chemistry model PROFILE was studied, on the following two parts, to calculate the critical loads for East Asian soils: (1) Dissolution rate coefficients of volcanic glass were derived from published experimental data, and calculated field weathering rate was compared with the rate estimated based on Sr isotope analysis. When BET surface area of sand fraction was regarded as mineral surface area, the calculated rates fairly agreed with the estimate, suggesting that sand fraction surface area is a reasonable estimate of weatherable mineral surface area of volcanic soils. (2) In repeated leaching experiments, Al solubility of a number of Japanese soils was explained by a model which assumed complexation of Al to soil organic matters. Such an Al solubility model is more appropriate for predicting soil chemistry than apparent gibbsite dissolution equilibrium.     

The feeding habits of collembola along decomposition gradients using stable carbon and nitrogen isotope analyses

We measured the natural stable carbon (C) and nitrogen (N) isotope ratio patterns of collembola and the organic substrates of their habitats and potential food sources in a warm temperate coniferous forest. Based on previous studies, we classified collembola into successional classes along litter decomposition gradients: early colonizers, late colonizers, and dominants-throughout. The stable C and N isotope ratios of late colonizers exceeded those of early colonizers, and those of the dominants-throughout were intermediate between early and late colonizers, which is consistent with previous studies on two macro-invertebrates, earthworms and termites. The C and N isotopic signature differences in collembola may reflect food resource partitioning along decomposition gradients.     

C(18) acetylenic fatty acids of Ximenia americana with potential pesticidal activity

Bioactivity-driven fractionation of the CHCl(3) extract of the root of Ximenia americana, using the brine shrimp lethality test (BST) and hatchability test with Clavigralla tomentosicollis eggs, gave C(18) acetylenic fatty acids 1 and 2. 1 is octadeca-5-ynoic acid (tariric acid). 2 is a novel ene-ene-yne-ene acetylenic fatty acid (10Z,14E,16E-octadeca-10,14,16-triene-12-ynoi c acid). The structures of 1 and 2 were assigned from the MS and NMR data. Fractions that are rich in acetylenic fatty acids inhibited the hatching of C. tomentosicollis eggs.     

Fungal ingrowth on forest floor and decomposing needle litter of Chamaecyparis obtusa in relation to resource availability and moisture condition

Fungi play an important role in litter decomposition in forest ecosystems and studies are needed to follow the changes in hyphal abundance during litter decomposition and examine the factors regulating the ingrowth of hyphae in litter. The purposes of the present study are to demonstrate the patterns of needle decomposition of Chamaecyparis obtusa in terms of the vertical distribution of fungal biomass and chemical properties within litter horizons (L1, L2, F, and H layers) and fungal ingrowth and succession in relation to organic chemical and nitrogen dynamics during needle litter decomposition over a one-year period. A further aim is to assess the effect of moisture and availability of organic matter on live hyphal length, during 1 year of decomposition. Live hyphal length was correlated to holocellulose concentration in four litter horizons. In a litter bag experiment, total (live plus dead) hyphal length increased during decomposition which was correlated to the concentrations of nitrogen, lignin, holocellulose, and soluble carbohydrate in the litter. The 12-month period over which decomposition was measured was divided into four seasons and the correlation between the water content and live hyphal length was evaluated for each period. The length of live hyphae was correlated to the water content of litter in all four periods. The slopes of regression lines between the water content and live hyphal length were positively correlated to the mean concentrations of soluble carbohydrate of each period, suggesting that the growth of live hyphae was highly dependent on the moisture condition of litter, and under moist conditions on the availability of soluble carbohydrate in the litter. The decrease in the slopes during decomposition can be ascribed to ecophysiological traits of fungi responsible for decomposition in these periods.     

Inhibition of post-mortem muscle softening following in situ perfusion of protease inhibitors in tilapia

ABSTRACT:     A method of introducing protease inhibitors into fish muscle through the bulbus arteriosus was developed using an in situ perfusion technique. Perfusion efficiency was initially tested using eosin and [³⁵S]-methionine. Visible fluorescence was observed in the gill, liver, intestine and dorsal muscle of the eosin-treated tilapia, and the occurrence of eosin in the blood vessels of the dorsal muscle was confirmed under a fluorescence stereoscopic microscope with ultraviolet light. The radioactivity of [³⁵S]-methionine was taken into the dorsal muscle and liver at a concentration of 7.8 Bq/g and 70.2 Bq/g, respectively, after perfusion with 1000 Bq/mL solution. Using the perfusion technique with four kinds of protease inhibitors dissolved in physiological saline, the type of proteases implicated in the post-mortem muscle softening in tilapia (867 ± 195 g, n  = 10/protease inhibitor) was investigated. After the perfusion of leupeptin (serine and cysteine protease inhibitor), benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-fmk; caspase inhibitor), chymostatin (serine protease inhibitor) and ο -phenanthroline (metalloprotease inhibitor), the breaking strength of the perfused muscle was measured as a parameter of the meat toughness and compared with that of the control fish, which were perfused with physiological saline only. The reduction of breaking strength during storage was inhibited by the perfusion of leupeptin and Z-VAD-fmk.     

Example of an adenocarcinoma developed in the gastric lymph nodes of a harbor seal Phoca largha

SUMMARY: Adenocarcinomatous growths comprising glandular cavities surrounded by cuboidal to low columnar cells and a large amount of mucus produced by the mucous cells, were observed in the the gastric lymph nodes of a harbor seal Phoca largha. The seal was stranded on the coast of Toyama Bay, Sea of Japan, on 2 March, 1998. Necroscopic examination also showed the animal had significant signet ring cell carcinoma in the stomach, as has been reported elsewhere. The adenocarcinoma may have developed from metastatic cells arising in the gastric carcinoma.     

The economic value of days open in Holstein cows in Japan based on simulated changes in conception rate

Increasing herd‐life length and culling parity with increasing conception rate (CR) is necessary to increase lifetime profit from dairy cow production. Economic values of days open (DO) were determined by calculating changes in fertility traits, herd‐life length, and milk yield when the simulated CR were changed in increments of 1% from ?5% to 5% from the basal levels, which were obtained for Hokkaido and regions other than Hokkaido separately. When CR increased, number of artificial inseminations, DO, and milking length decreased. Furthermore, culling parity, and annual milk yield increased. Herd‐life length increased in Hokkaido and decreased in the other regions. The economic values of CR were 1,623.8 to 946.8 yen and of DO were 857.4 to 399.0 yen. Relative economic values of milk yield to days open per genetic standard deviation were higher in the other regions than in Hokkaido where the economic effect of selection for DO was expected to be equal to selection for 305‐day milk yield and herd life. If the survival rate of multipara cows in the other regions increases, then the economic value of DO would similarly increase in Hokkaido.