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31.
Root biomass and root distribution were studied in Entisols derived from the thick deposition of volcanic pumice on Hokkaido
Island, Japan, to examine the effect of soil conditions on tree root development. The soil had a thin (<10 cm) A horizon and
thick coarse pumiceous gravel layers with low levels of available nutrients and water. Two stands were studied: a Picea glehnii–Abies sachalinensis stand (PA stand) and a Larix kaempferi–Betula platyphylla var. japonica stand (LB stand). The allometric relationships between diameter at breast height (DBH) and aboveground and belowground biomass
of these species were obtained to estimate stand biomass. The belowground biomass was small: 30.6 Mg ha−1 for the PA stand and 24.3 Mg ha−1 for the LB stand. The trunk/root ratios of study stands were 4.8 for the PA stand and 4.3 for the LB stand, which were higher
than those from previous studies in boreal and temperate forests. All species developed shallow root systems, and fine roots
were spread densely in the shallow A horizon, suggesting that physical obstruction by the pumiceous layers and their low levels
of available water and nutrients restricted downward root elongation. The high trunk/root ratios of the trees may also have
resulted from the limited available rooting space in the study sites. 相似文献
32.
To determine the independent decomposition rates of lignin and cellulose of decayed woody debris, a technique for the rapid analysis of lignin and cellulose is required. We applied a near-infrared spectroscopy (NIRS) technique to measure the lignin and holocellulose content in decayed wood. We succeeded in creating partial least-squares (PLS) models to estimate the lignin and holocellulose content in the decayed wood of five species using NIR spectra. Although the accuracy was acceptable for the estimation of a five-species mixed model (R 2 = 0.970 for lignin and R 2 = 0.962 for holocellulose), it was further improved when the model was applied to each species independently. This combination of NIRS and a PLS model is a valuable tool for the determination of the lignin and holocellulose content in decayed wood. The technique is time efficient (3 min per sample) and non-hazardous (no acid treatment is required). 相似文献
33.
Sato E Kohno M Hamano H Niwano Y 《Plant foods for human nutrition (Dordrecht, Netherlands)》2006,61(4):157-160
Fundamental anti-oxidative properties of 80% ethanol extract from garlic fermented for the relatively short period of time (40 days at 60–70°C, 85–95% relative humidity) were examined. Superoxide dismutase (SOD)-like activity, scavenging activity against hydrogen peroxide and the polyphenol content of the garlic extract were increased 13-folds, more than 10-folds, and 7-folds, respectively, as compared with those of the control garlic extract. The results indicate that relatively short-term spontaneous fermentation potentiates anti-oxidative properties of garlic in fresh form, which is, at least in part, attributable to the increased level of polyphenols. Since superoxide is the primary upstream radical of the chain reaction with reactive oxygen species and hydrogen peroxide is generated from the scavenging reaction by SOD, the fermented- garlic is suggested to possess desirable anti-oxidative properties. 相似文献
34.
Ryoichi Ikeda Yoshimi Sokei Inoussa Akintayo 《Genetic Resources and Crop Evolution》2007,54(8):1637-1644
A comparison of breeder seed from different seed sources produced guidelines for multiplication of NERICA (New Rice for Africa)
varieties. Lower percentage detection of offtypes was noted with seed from a breeder than with seed from the Genetic Resources
Unit (GRU) of the Africa Rice Center. The GRU grows breeder seed in the field as bulk populations of varieties and this seed
is multiplied for the foundation seed. Breeders, however, always cultivate the variety in each family with several lines.
In the comparison, each NERICA variety was cultivated as a single plant per hill for easy offtype detection in the field.
Any offtypes or doubtful plants were recorded and immediately discarded. The breeder seed was not always genetically uniform
because it was not yet fixed genetically and included mechanical seed mixture as well as natural mutants. Offtypes were classified
into categories such as chlorophyll mutants, aberrations of plant height, plant types and panicle types, semi- or high sterility,
awnness, apiculous color, leaf sheath color and excessively early plants. The causes of these offtypes were mainly (1) mechanical
seed mixture, (2) segregation in genetically-unfixed material, (3) out-crossing with another variety, or (4) natural mutation.
In 2006, we multiplied foundation seed using used home-saved seed from the 2005 crop harvested after removal of offtypes.
The detection percentage of offtypes decreased compared with the previous year, but the number of semi- or high sterility
plants increased significantly. This review confirms that breeder seed must be maintained with line culture within a family. 相似文献
35.
Samad RA Sakoda Y Tsuda Y Simulundu E Manzoor R Okamatsu M Ito K Kida H 《The Japanese journal of veterinary research》2011,59(1):15-22
Recent introduction of H5N1 highly pathogenic avian influenza virus (HPAIV) in wild birds from poultry in Eurasia signaled the possibility that this virus may perpetuate in nature. Surveillance of avian influenza especially in migratory birds, therefore, has been conducted to provide information on the viruses brought by them to Hokkaido, Japan, from their nesting lakes in Siberia in autumn. During 2008-2009, 62 influenza viruses of 21 different combinations of hemagglutinin (HA) and neuraminidase (NA) subtypes were isolated. Up to September 2010, no HPAIV has been found, indicating that H5N1 HPAIV has not perpetuated at least dominantly in the lakes where ducks nest in summer in Siberia. The PB2 genes of 54 influenza viruses out of 283 influenza viruses isolated in Hokkaido in 2000-2009 were phylogenetically analysed. None of the genes showed close relation to those of H5N1 HPAIVs that were detected in wild birds found dead in Eurasia on the way back to their northern territory in spring. 相似文献
36.
Fabricio F. T. Domingos Ralph G. Thomé Fabio P. Arantes Antonio Carlos S. Castro Yoshimi Sato Nilo Bazzoli Elizete Rizzo 《Fish physiology and biochemistry》2012,38(6):1709-1719
River damming and building of hydroelectric power plants interrupt the reproductive migration routes and change the major physicochemical parameters of water quality, with drastic consequences for populations of migratory fishes. The goal of this study was to evaluate proliferation and cell death during spermatogenesis and serum profiles of sex steroids in Prochilodus argenteus, from the S?o Francisco River, downstream from the Três Marias Dam. A total of 257 adult males were caught quarterly during a reproductive cycle in two sites: the first 34?km of the river after the dam (site 1) and the second 34–54?km after the dam (site 2), after the confluence with a tributary, the Abaeté River. Seasonal changes in the testicular activity associated with morphometric analyses of germ cells as well as proliferation and testicular apoptosis support a more active spermatogenesis in fish from site 2, where higher levels of sex steroids and gonadosomatic index (GSI) were also found. In site 1, fish presented low serum levels of testosterone, 17β-estradiol and 17α-hydroxyprogesterone and a low GSI during gonadal maturation. Spermatogonial proliferation (PCNA) and apoptosis (TUNEL) were more elevated in fish from site 1, but spermatocytes were mainly labelled in fish from site 2. Overall, these data demonstrate changes in testicular activity and plasma sex steroids in a neotropical teleost fish living downstream from a hydroelectric dam, supplying new data on fish reproduction in regulated rivers. Moreover, morphometric analyses associated with sex steroids profiles provide reliable tools to assess fish spermatogenesis under environmental stress conditions. 相似文献
37.
Akira Yoshimi Junko Imanishi Abdul Gafur Chihiro Tanaka Mitsuya Tsuda 《Journal of General Plant Pathology》2003,69(2):101-108
Laboratory mutants of Cochliobolus heterostrophus resistant to iprodione were obtained after chemical mutageneses. All the mutants were able to grow on the medium amended
with iprodione 100 μg/ml. They showed positive cross-resistance to procymidone and fludioxonil and were sensitive to high
osmolarity. Crosses between the mutant and a wild-type strain revealed that the fungicide resistance and osmotic sensitivity
traits were inherited by their offspring in a 1 : 1 mutant/wild type ratio, indicating that the mutant phenotypes in these
strains were due to alteration at a single gene locus. Results from allelism tests indicated that three genes (Dic1, Dic2, Dic3) conferred the mutant phenotypes. Among them, Dic1 mutant strains were classified into three types on the basis of their phenotypes. The first type was moderately resistant
to the fungicides and less sensitive to osmotic stress than the other Dic1 mutant strains. The second type showed moderate fungicide resistance, but growth was inhibited under lower osmotic stress
(50 mM KCl). The other Dic1 mutant strains grew well on medium containing iprodione and fludioxonil even at a concentration of 100 μg/ml and were highly
sensitive to osmotic stress. The Dic2 and Dic3 mutant strains had moderate resistance to the fungicides with low-level osmotic sensitivity. The Dic1 gene was epistatic to Dic2 and Dic3 for fungicide resistance and hypostatic to them for osmotic sensitivity. These results suggest that the osmoregulatory system
is involved in fungicide resistance in laboratory mutants of C. heterostrophus.
Received: March 14, 2002 / Accepted: August 13, 2002 相似文献
38.
Kaempferol-3-O-gentiobioside, the major flavonoid glycoside in Indonesian Cassia alata was quantified in various parts of the plant. The mature leaf was found to contain the highest content of this metabolite. A decrease of the flavonoid content in the juvenile leaf during the period of October through December was also observed. The contents ranged from 2.0 to 5.0% and 1.0 to 4.0% in mature and juvenile leaves, respectively. The other parts studied were flower (sepal and petal), rachis, stem and seed. Kaempferol-3-O-gentiobioside was not detected in the seed. 相似文献
39.
Hiraoka H Shimada Y Sakata Y Watanabe M Itamoto K Okuda M Masuzawa T Inokuma H 《Veterinary parasitology》2007,144(1-2):188-192
Ticks removed from 1136 dogs and 134 cats all over Japan were examined for Borrelia infection by PCR and sequencing. The 5S-23S rDNA intergenic spacer of Borrelia was detected from two Ixodes persulcatus ticks from two dogs and two unidentified Ixodes spp. from another two dogs in Hokkaido, and two Ixodes granulatus ticks from two cats in Okinawa. Additional 2 I. granulatus from the same cats also showed positive. Sequence analysis of the PCR products revealed that the one from Hokkaido was similar to B. garinii, the three from Hokkaido to B. tanukii, and the four from Okinawa to a novel Borrelia sp. closely related to B. valaisiana. The data was confirmed by analysis of the flagellin gene sequence. Infected ticks carried by companion animals can be introduced into the human environment. 相似文献
40.
Akio Manabe Masayuki Enomoto Yoshimi Yamada Yukio Oguri Mitsuru Sasaki 《Pest management science》1999,55(6):649-650
The four diastereomers of 2-cyano-N-[1-(2,4-dichlorophenyl)ethyl]-3,3-dimethyl-butyramide were prepared by a direct HPLC separation with chiral columns. The [(S)acid, (R)amine]-isomer (was the most antifungal among the diastereomers tested. Because of the lability of the clinical group in the acid moiety, the (RS)-(R)-isomer is being developed as a rice blasticide. (S-2900, proposed common name diclocymet). 相似文献