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21.
Journal of Plant Diseases and Protection - The antagonistic rhizobacterium, Pseudomonas fluorescens strain LRB3W1, controls cabbage Fusarium yellows caused by Fusarium oxysporum f. sp. conglutinans... 相似文献
22.
Toshiyuki Usami Shu Ishigaki Hiroko Takashina Yuko Matsubara Yoshimiki Amemiya 《Journal of General Plant Pathology》2007,73(2):89-95
Japanese isolates of Verticillium dahliae, a causal agent of wilt disease in many plants, are classifiable into pathotypes based on their pathogenicity. Because these
pathotypes are morphologically indistinguishable, establishing a rapid identification method is very important for the control
of this pathogen in Japan. For cloning DNA fragments that are useful for identification and specific detection of V. dahliae pathotypes, we performed random amplified polymorphic DNA (RAPD) analyses using various isolates. One polymerase chain reaction
(PCR) product, E10-U48, was specific to isolates pathogenic to sweet pepper. The other product, B68-TV, was specific to race
1 of isolates pathogenic to tomato. The specificity of these sequences was confirmed by genomic Southern hybridization. Further
analyses revealed that the region peripheral to B68-TV obtained from the genomic DNA library includes the sequence specific
to all isolates pathogenic to tomato (races 1 and 2). Moreover, sequence tagged site (STS) primers designed from B68-TV and
its peripheral region showed race-specific and pathotype-specific amplification in a PCR assay. The probes and primers obtained
in this study are likely to be useful tools for the identification and specific detection of pathotypes and races of V. dahliae.
The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession number AB095266. 相似文献
23.
Ichiki Takemoto Ryo Yoshida Seizo Sumida Katsuzo Kamoshita 《Pesticide biochemistry and physiology》1985,23(3):341-348
Relationships between three types of herbicidal activity of N′-substituted phenyl-N-methoxy-N-methylureas and substitution at the benzene ring were analyzed by the Hansch-Fujita method. First, the Hill inhibitory activity was correlated with electronic (σ) as well as hydrophobic (π) substituent constants. The existence of an optimum value of hydrophobicity for substituents was suggested to reach the target site of action. Second, bliaching activity observed for the 3-substituted but not for 4-substituted compounds was correlated with π, σ, and steric substituent constant, Es. Third, the postemergent herbicidal activity was shown to correlate linearly with the Hill inhibitory activity, pI50, and hydrophobic parameter, π. 相似文献
24.
Kazumasa Yoshida Mitsuru Nishiguchi Shojiro Hishiyama Atsushi Kato Koetsu Takahashi 《Journal of Wood Science》2006,52(4):372-375
Sugi (Cryptomeria japonica D. Don) produces secondary metabolite norlignans in xylem. Several norlignans are involved in the coloration of heartwood
and defense of sapwood against microbial invasion. Their biosynthetic process should be well understood so that their properties
can be exploited to improve the quality and utility of C. japonica wood. Unfortunately, information on the norlignan biosynthesis is limited because norlignans are mainly synthesized in a
particular season in the transition zone (TZ) along with the heartwood formation, and is difficult to study. Although the
generation of two norlignans of C. japonica, agatharesinol and (E)-hinokiresinol, has been reported, systems for producing other norlignans are not yet known. To establish a novel norlignan
generating system, we examined the changes occurring in norlignans in a TZ during the process of drying a C. japonica log. On the day of felling, the TZ contained agatharesinol and (E)-hinokiresinol, which increased until they reached a maximum on day 40 after felling. Sequirin-C appeared on day 40 and increased
to day 70. The generation of sequirin-C in the TZ can be used to investigate the biosynthetic process of heartwood norlignans.
This study describes for the first time the changes that occur in the composition of norlignan during the drying of the TZ. 相似文献
25.
We derived an allometric model of the height–diameter curve for even-aged pure stands, which was a modification of the earlier
model proposed by Inoue (2000a). An individual-dependent allometric equation was used as the height–diameter curve. Using
the discriminant analysis method, all trees composed of a stand were stratified into upper and lower trees. It was assumed
that both relationships between mean tree height H
m
and upper tree height H
u
and between mean DBH D
m
and mean DBH of upper trees D
u
could be described by the time-dependent allometric power equations. The height–diameter curve showed an average relationship
between tree height and DBH of a given stand at a given time, and hence it could be assumed that the height–diameter curve
contained two points (D
m
, H
m
) and (D
u
, H
u
). With these assumptions, we derived an allometirc model of height–diameter curve, which allowed the coefficients of the
curve to be estimated from mean tree height and mean DBH. The proposed model was fitted to Japanese cedar (Cryptomeria japonica D. Don) data. The error ratio of the allometric model ranged from 2.254% to 13.412% (mean = 6.785%), which was significantly
smaller than that of the earlier model. When the error of mean tree height was ±1.0 m or less, the effect of the error of
mean tree height on the error ratio was comparatively small. This suggested that the error of ±1.0 m in mean tree height could
be accepted in the estimation of height–diameter curve using the allometric model. These features enable us to combine the
allometric model with Hirata’s vertical angle-count sampling or growth models. In conclusion, the allometric model would be
one of the most practical and convenient approaches for estimating the height–diameter relationship of even-aged pure stands. 相似文献
26.
Tsuyoshi Kajisa Takuhiko Murakami Nobuya Mizoue Shigejiro Yoshida 《Journal of Forest Research》2007,12(6):435-441
Our objective was to investigate the differences in the spectral trajectory of the LANDSAT Thematic Mapper with stand volume
development between Japanese larch (Larix kaempferi) and Japanese oak (Quercus mongolica var. crispula) in the experimental forest of Kyushu University, Hokkaido, Japan. We used nonlinear regression and a categorical variable
to investigate the relationship between spectral reflectance factor and stand volume for each forest type. This research showed
that the reflectance factor of Japanese larch and Japanese oak reached saturation and that both forest types had different
spectral trajectories with stand development. In addition, we found that middle of development stage (stand volume was between
100 and 200 m3/ha) of each forest type had similarity in reflectance factor. 相似文献
27.
Koji Yoshida Shoko Inaba Chisato Takenaka Takafumi Tezuka 《Journal of Forest Research》2005,10(2):157-161
To clarify the nutrient status in momi fir (Abies firma Sieb. et Zucc.) seedlings under complex stress conditions of acid fog with soil acidification or nitrogen loading, we exposed seedling shoots to simulated acid fog (pH 3) and simultaneously loaded the soil with acid or excess nitrogen for 17 months. Proton and nitrogen loading reduced K concentration in soil, but these treatments had little effect on the nutrient status of fine roots in momi fir seedlings. Acid fog exposure resulted in reduced concentrations of Mg, Al, and Fe in current-year needles and Mg, Al, Cu, Fe, and Zn in 1-year-old needles. The complex effects of acid fog exposure with proton or nitrogen loading on nutrient status were relatively slight. However, elements such as Al and Cu notably reflect the effects of proton loading. These results show that the nutrient status of trace elements, rather than major elements, in needles of momi fir seedlings is sensitive to exposure to acid fog or proton loading. 相似文献
28.
Shigeki Yoshida Atsushi Kuno Naoto Saito Masakazu Aoyama Isao Kusakabe 《Journal of Wood Science》1998,44(6):457-462
Xylan prepared from culms of kumaizasa (Sasa senanensis Rehd.), a representative species of bamboo grass, was hydrolyzed with-xylanase ofStreptomyces olivaceoviridis E-86. Four arabinoxylo-oligosaccharides and two glucuronoxylo-oligosaccharides were isolated from the enzymatic hydrolysate of the xylan by chromatography on a charcoal column, a Dowex 1-x8 column, a Toyo-pearl HW-40S column, and a LiChrospher 100 NH2 column and on preparative paper chromatography. The results of the structural analyses of the saccharides showed that the isolated oligosaccharides had the structures of 32--l-arabinofuranosyl-xylobiose, 32--l-arabinofuranosyl-xylotriose, 32--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylobiose, 33--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylotriose, 23--4-O-methyl-d-glucuronosyl-xylotriose, and 23--d-glucuronosyl-xylotriose. From the structural analysis of the oligosaccharides derived from the xylan, kumaizasa xylan was concluded to be a kind of arabinoglucuronoxylan having not only stubs of singlel-arabinose and singled-glucuronic acid but also stubs of disaccharide units such as-d-xylopyranosyl-(1 2)-l-arabinofuranose. 相似文献
29.
Sujan KC Yamamoto Hiroyuki Matsuo Miyuki Yoshida Masato Naito Kazuhiro Shirai Tatsuya 《Wood Science and Technology》2015,49(6):1157-1169
Wood Science and Technology - Tension wood, when kiln-dried, is likely to deform hugely, which is probably caused by a gelatinous layer of the gelatinous fiber. To elucidate the mechanism behind... 相似文献
30.
Endometrial adenocarcinoma in the uterine corpus is a malignant cancer that occurs in menopausal women and aged rodents. Because of the similarities in pathogenesis and morphology of endometrial adenocarcinoma in rodents and humans, prediction of the modes of action (MOA) in uterine carcinogenesis is important for extrapolation of rodent data to humans. Three MOAs have been accepted as major pathways for uterine carcinogenesis in rodents: 1) estrogenic activity, 2) increased serum 17beta-estradiiol (E2) to progesterone (P4) ratio and 3) modulation of estrogen metabolism to produce 4-hydroxyestradiol via P450 induction. Inhibition of estrogen excretion and increased aromatase in situ in the tumor are also a potential pathway. Here, chemicals showing uterine carcinogenicity were chosen from approximately 300 pesticides evaluated in Japan within the past decade, and their mechanisms were predicted using parameters from mechanistic and toxicity studies. Seven pesticides increased uterine tumor formation in rats, and the pathways of 4 pesticides could be predicted based on various mechanistic studies. The MOAs of cyenopyrafen and benthiavalicarb-isopropyl were predicted to be modulation of estrogen metabolism, while those of pyriminobac-methyl and spirodiclofen were predicted to be increased E2 to P4 ratio. The driven pathways of metazosulfuron and isopyrazam could not be predicted using several mechanistic studies. No mechanistic studies have been reported for sedaxane, which has a chemical structure and toxicological profile similar to isopyrazam. Our results indicated that appropriate mechanistic studies are useful for mechanism prediction in risk assessment. From this analysis, a flowchart showing a decision tree for predictive MOAs in uterine carcinogenesis was proposed. 相似文献