Assessment of biochemical and antioxidant diversities in a shallot germplasm collection from Vietnam and its surrounding countries

The shallot is considered an important genetic resource for Allium breeding programs because, compared to the bulb onion, the shallot contains higher levels of several functional chemical compounds. However, there may be differences in content, composition and beneficial activity among shallot landraces. This study was carried out to characterize the differences in phenolic, quercetin, sugar, S-alk(en)yl-l-cystein sulfoxide (ACSO), and saponin contents and antioxidant capacities of a shallot germplasm including 31 strains derived from different regions of Vietnam and six other countries. A wide variation was observed in the quantitative analyses of the chemical contents. Shallots with high contents of polyphenols, saponins, and quercetins were found in the south of Vietnam and other low-latitude countries. Meanwhile, those possessing fairly high ACSO and sugar contents were observed in the north of Vietnam. Qualitative analysis of saponins via thin layer chromatography did not show clear variation among shallot strains, but polymorphism was observed between the shallot and other Allium species, such as A. roylei. The principal component analysis could clearly discriminate shallot strains by their geographical origins. All shallot strains showed potent antioxidant activities in a DPPH assay. The highest antioxidant capacity was in the strains possessing relatively high contents of polyphenol, quercetin, and saponin. Significant correlations were found between antioxidant capacity (IC ₅₀ ^?1 ) and four groups of chemical compounds (polyphenols, quercetins, saponins, and ACSOs) (r = 0.40–0.59). A strong correlation was observed between IC ₅₀ ^?1 and quercetin contents (r = 0.59, p < 0.01). The six Fusarium-inoculated shallot strains seemed to be adequately resistant against disease, and the levels of resistance may be related to the saponin content in the bulb tissues.     

Comparison of glycerol, lactamide, acetamide and dimethylsulfoxide as cryoprotectants of Japanese white rabbit spermatozoa

The rabbit is considered to be a valuable laboratory animal. We compared glycerol, lactamide, acetamide, and dimethylsulfoxide (DMSO) as cryoprotectants in egg-yolk diluent of ejaculated Japanese white rabbit spermatozoa for improvement of sperm cryopreservation methods. Rabbit semen was frozen with 1.0 M glycerol, lactamide, acetamide, or DMSO in plastic straws. Forward progressive motility and plasma membrane integrity of the post-thaw spermatozoa were examined. The rate of forward progressive motile spermatozoa in lactamide (37.8 +/- 3.0%) was significantly (P<0.05) higher than in glycerol (17.0 +/- 3.3%). In addition, the rates of sperm plasma membrane integrity in lactamide and acetamide (35.9 +/- 3.3% and 30.2 +/- 3.0%, respectively) were significantly (P<0.05) higher than in glycerol (17.0 +/- 2.6%). The results indicate that 1.0 M lactamide and acetamide have higher cryoprotective effects than 1.0 M glycerol for cryopreservation of Japanese white rabbit spermatozoa.     

Ligation of caeca improves nitrogen utilisation and decreases urinary uric acid excretion in chickens fed on a low protein diet plus urea

1. The effect of the ligation of the caeca on nitrogen utilisation and nitrogen excretion was examined in conventional chickens fed a diet containing 50 g protein/kg plus urea.

2. Ligation of the caeca significantly improved nitrogen balance and utilisation by up to more than 2 times as much as those of controls (P< 0.05).

3. The treatment significantly decreased uric acid excretion by 77 mg nitrogen/day (P< 0.01) and also total nitrogen excretion (P<0.05): the former decrease almost explained the latter.

4. No effect of the ligation of caeca on urea and ammonia excretion was observed.

5. It is concluded that nitrogen metabolism in chickens is affected by possible changes in caecal fermentation by preventing entry into the caeca of substances from urine and digesta.     

Monitoring of the genetic variability of the hatchery and recaptured fish in the stock enhancement program of the rare species barfin flounder <Emphasis Type="Italic">Verasper moseri</Emphasis>

ABSTRACT:   In relation to the stock enhancement program for barfin flounder, hatchery juveniles produced in 2001 were genotyped using microsatellite DNA markers (msDNA) and then released to natural waters. Subsequently, recaptured individuals, designated as 'tentative recaptured', were examined using msDNA. In order to evaluate the effectiveness of the stock enhancement program, pairwise F _ST and genic differentiation tests were used to estimate the genetic divergence between the wild samples, the hatchery broodstock, and the tentative recaptured samples. Analysis showed significant differentiation among these three groups. Pedigree determination by msDNA was used to establish the origin of the tentative recaptured individuals, in order to elucidate whether they were hatchery produced, 'real recaptured', or wild specimens. Wild individuals were not found. The effective population size of the real recaptured stock was very low ( N _e = 16.6). Equal family survivability was observed between the released and real recaptured stocks, indicating that the genetic variability of the released stock was maintained in the natural environment. Future broodstock management, breeding designs, and family contribution equalization of the offspring to be released will be required in this rare species to avoid unintended genetic differentiation between the wild population and the hatchery broodstock.     

Clay minerals of soils from olivine basalt in Kyushu

Soil scientists have been encouraged to investigate soils for clay minerals by very fact that soil characteristics fundamentally depend upon the nature of their clay. It is generally recognized that clays of different species develop under different conditions such as drainage, temperature weathering age, and parent rocks. On Kyushu Island, heavy, reddish soils derived from olivine basalt cover a considerably large area of its northeastern part, and a numbar of small islands belonging to Kyushu. Koga ^* Hiroshi Koga, Clay minerals of Oura basaltic soil, 1954 (unpublished). of this laboratory found a basaltic soil of clay consisting of hydrated halloysite, halloysite, hematite, and gibbsite at the eastern foot of Mt. Tara, by examining its clay separates by X-ray, thermal, chemical, and electron microscopical techniques. Kanno et al⁵ reported that in a basaltic soil at Oura, Saga prefecture, hydrated halloysite developed from plagioclase and ferro-magnesian minerals with gibbsite and hematite which was more abundant than in other Red and Yellow Soils. They also found some illite present in the soil derived from unknown minerals, and halloysite dehydrated in upper layers.     

An efficient molecular technique for sexing tiger pufferfish (fugu) and the occurrence of sex reversal in a hatchery population

The tiger pufferfish (fugu) is one of the most important food fishes in East Asia. Since its testes are regarded as a delicacy, sex determination is economically relevant. Previous studies have identified a missense single-nucleotide polymorphism (SNP) in the Amhr2 (anti-Müllerian hormone receptor type II) gene as a strong candidate for a master sex-determining polymorphism. To distinguish genotypic sex efficiently, we developed a high-resolution melting (HRM) assay for this SNP site. By screening 396 fish from two independent crosses reared under controlled conditions, we observed perfect concordance between the SNP genotype and phenotypic sex. Thus, this method holds great potential for use in high-throughput sexing. When analyzing 293 progeny from a third cross reared under unknown conditions, we unexpectedly found that 25 % of phenotypic males exhibited female genotype. These results suggest that environmental factors such as rearing conditions could influence the sex-determination pathway in pufferfish. Alternatively, genetic modifiers might override the signals from Amhr2. This finding raises a concern regarding enhanced stock management of this species, because sex-reversed fish could compromise the sex ratio in subsequent generations. The HRM assay will also be useful for monitoring the degree of sex reversal before release.     

Clay mineralogy of some volcanic ash soils in which cristobalite predominates

The clay mineralogical composition of soils on volcanic ashes from Mashū and Kamuinupuri-dake volcanoes, Hokkaido, which are rich in cristobalite, was determined using petrological, X-ray diffraction, differential thermal, and selective dissolution and differential infrared spectroscopic methods.

The cristobalite occurred in abundance in every size of fraction from coarse sand to clay and every soli from approximately 1,700 to 8,400 years old, and was concluded to be of igneous origin. The major clay minerals were allophanelike constituents and allophane with some layer silicates as the minor clay mineral, being similar to those of andesitic ash soils and different from those of volcanic ash soils containing abundant quartz. The quartz of volcanic ashes was presumed to bederived from the groundmass-equivalent portion of the ashes which had been formed from magma at a low temperature.     

Combustion gas toxicity,hygroscopicity, and adhesive strength of plywood treated with flame retardants

Summary The results of tests of combustion toxicity, hygroscopicity, and adhesive strength for fire retardant-treated plywood are described. The plywood was prepared from veneers treated with diammonium phosphate and ammonium bromide, and from glue mixed with poly (ammonium phosphate). Furthermore, the plywood boards were coated with boric acid. High ammonium phosphate and low or 0 ammonium bromide contents with the boric acid-coatings gave the greatest improvement in the combustion toxicity. Influence of almost all the treatments on the hygroscopicity was not significant. In all treatments the dry adhesive strength and the cyclic boil adhesive strength were slightly and considerably reduced, respectively.     

Positional effect of gene insertion on genetic stability of a clover yellow vein virus-based expression vector

The stability of the inserted genes in the viral expression vector varied depending on the sequence introduced and the position of insertion. Infectious cDNA to Clover yellow vein virus (pClYVV) was modified to insert a foreign gene at two independent sites: one, along with a polylinker, between the NIb and CP genes (pClYVV/CP/W) and the other between P1 and HC-Pro (pClYVV-Pst/CP). The green fluorescent protein (GFP) gene was inserted into either pClYVV/CP/W or pClYVV-Pst/CP. GFP gene was stably maintained and expressed in both vectors following serial passages in plants. Progeny viruses from both constructs accumulated in similar amounts and at rates of 70%–80% of that of the wild-type virus. On the other hand, progeny viruses carrying the human interferon- (hIFN) gene cloned in pClYVV-Pst/CP were genetically unstable owing to frequent deletions of the cloned gene during passage through plants. In contrast, the hIFN sequence cloned in pClYVV/CP/W was stably maintained in viruses after several passages in broad bean plants, and the progeny virus accumulated at the rate of about 50%–100% of that of the wild-type virus. The nucleotide sequence analyses indicated that the genetic instability of the inserted sequence results from homologous recombination of viral vector and inserted DNA sequences; it is not due to the inserted sequence alone.