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101.
Akhil Ranjan Baruah Noriko Ishigo-Oka Mieko Adachi Yasuyo Oguma Yoshiro Tokizono Kazumitsu Onishi Yoshio Sano 《Euphytica》2009,165(3):459-470
The present study was conducted to understand the pattern of variation and the genetic bases for cold tolerance at the early
growth stage in Asian rice. The genetic variation was investigated at the germination, plumule and seedling stages among 57
strains including cultivated rice (Oryza sativa ssp. indica and ssp. japonica) and its wild progenitor (Oryza rufipogon). The significant differentiation of cold tolerance was observed among the taxonomically divided groups. At the germination
stage, both indica and japonica subspecies tended to be more tolerant than O. rufipogon, whereas at the plumule and seedling stages, ssp. japonica tended to be more tolerant than ssp. indica and O. rufipogon. Furthermore, in cold tolerance at the plumule stage, the clinal variation across the latitude of origins was observed within
O. rufipogon and ssp. japonica, suggesting that the current pattern of variation seems to have been shaped by both their phylogenetic histories and on-going
adaptation to the local environments. QTL analysis between O. sativa ssp. japonica (tolerant) and O. rufipogon (susceptible) revealed five putative QTLs for cold tolerance at the plumule and seedling stages but not at the germination
stage. Substitution mapping was also carried out to precisely locate the two major QTLs for cold tolerance at the plumule
stage, which could be used for improvement of tolerance to cold stress in ssp. indica. 相似文献
102.
Koji Adachi Katsuhiro Takehira Tomoaki Soma Masafumi Inoue 《Journal of Wood Science》2010,56(6):502-506
The withdrawal strength of a bolt-nut connector made from wood-based material was evaluated. The thread strength of the wooden
bolt-nut connector was tested to select various parameters of the connector and the type of wood material; the wood materials
tested were hard maple, white oak, ebony, glue-laminated bamboo, and densified Japanese cedar. A plane model of wooden threads
with various thread angles was also evaluated. The results showed that the maximum failure load of the thread increased with
increasing bolt density and connection area, which was calculated from the diameter of the bolt and the thickness of the nut.
The withdrawal resistance after reaching the maximum load underwent a graded decrease because the bolt threads were broken
one by one. In addition, the thread strength depended on the thread angle. In the model with a thread angle of 90°, compressive
deformation in the transverse direction occurred prior to shear deformation along the root of the threads; the model with
this thread angle thus had higher strength than those with other angles. 相似文献
103.
Katsuki Adachi Masaaki Omine Mitsuho Sugimoto Takanori Ishii Hiroshi Niimi Takayuki Suzuki 《Plant Production Science》2016,19(1):125-131
We developed transplantation cultivation method of case-held tuber seedlings (CTS), which was derived from direct planting method of seed tubers, and applied this method to the sweet potato cultivar Beniharuka. A plastic case made of polypropylene was designed for cultivation of CTS. Seed tubers of cultivar Beniharuka in the range of 30–80 g were cut in half. The half-cut tubers were placed inside the plastic cases, and the cases were filled with a commercial soil mix. The case-held tubers were incubated under natural sunlight in a glass house. After 3–4 wk, the CTS were transplanted into a field. Mother tuber (seed tuber) enlargement was suppressed by the plastic confinement of the cases, and daughter tubers were formed above the case as vine-root-originated tubers. In the field experiments in 2012 and 2013, daughter tuber yields were increased 19% and 21% by case-held tuber seedling transplanting (CTST) over conventional vine-planting (VP), the number of daughter tubers per plant in CTST were 36 and 68% higher than in VP, and the mother tuber yields were limited to 2.1 and 4.3% of the total fresh yield of mother and daughter tubers, respectively in 2012 and 2013. Application of CTST method to cultivar Beniharuka enhanced tuber yield, increased the number of daughter tubers per plant, downsized daughter tubers compared to VP, and mother tuber enlargement was suppressed by case-holding. The CTST method is expected to produce more and smaller good in shape tubers of cultivar Beniharuka compared to VP. 相似文献
104.
Wind‐induced stock variation of the neon flying squid (Ommastrephes bartramii) winter–spring cohort in the subtropical North Pacific Ocean
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Haruka Nishikawa Takahiro Toyoda Shuhei Masuda Yoichi Ishikawa Yuji Sasaki Hiromichi Igarashi Mitsuo Sakai Masaki Seito Toshiyuki Awaji 《Fisheries Oceanography》2015,24(3):229-241
Our examination of the neon flying squid (Ommastrephes bartramii) winter–spring cohort catch per unit effort (CPUE, an index of stock) revealed significant positive correlations with the interannual variations of observed chlorophyll‐a (Chl‐a) concentration and autumn–winter mixed layer depth (MLD) in the winter–spring feeding grounds of paralarvae and juveniles (130–170°E, 20–27°N). These correlations suggest the importance of integrated bottom‐up effects by the autumn–winter MLD for the neon flying squid stocks. However, the influence of autumn–winter MLD interannual variation in the forage availability for paralarvae and juveniles, i.e., particulate organic matter and zooplankton, has still been unclear. In this study, we use the lower trophic ecosystem model NEMURO, which uses the physical environmental data from the ocean reanalysis dataset obtained by the four‐dimensional variational (4DVAR) data assimilation method. The model‐based investigation enables us to clarify how the autumn–winter MLD controls the particulate organic matter and zooplankton abundance in the feeding grounds. Further, our investigation of the autumn–winter MLD interannual variation demonstrates that the stronger autumn wind in the feeding grounds develops a deeper mixed layer. Therefore, the deep mixed layer entrains nutrient‐rich water and enhances photosynthesis, which results in good feeding conditions for paralarvae and juveniles. Our results underline that the wind system interannual variation has critical roles on the winter–spring cohort of the neon flying squid stock. 相似文献
105.
Keisuke Katsura Shuhei Maeda Iskandar Lubis Takeshi Horie Weixing Cao Tatsuhiko Shiraiwa 《Field Crops Research》2008
A number of field trials on rice productivity have demonstrated very high yield, but reported limited information on environmental factors. The objective of this study was to reveal the environmental factors associated with high rice productivity in the subtropical environment of Yunnan, China. We conducted cross-locational field experiments using widely different rice varieties in Yunnan and in temperate environments of Kyoto, Japan in 2002 and 2003. The average daily radiation throughout the growing season was greater at Yunnan (17.1 MJ m−2 day−1 average over 2 years) relative to Kyoto (13.2 MJ m−2 day−1). The average daily temperature throughout the growing season was 24.7 °C at Yunnan, and 23.8 °C at Kyoto. The highest yield (16.5 tonnes ha−1) was achieved by the F1 variety Liangyoupeijiu at Yunnan in 2003, and average yield of all varieties was 33% and 39% higher at Yunnan relative to Kyoto in 2002 and 2003, respectively. There was a close correlation between grain yield and aboveground biomass at maturity, while there was little variation in the harvest index among environments. Large biomass accumulation was mainly caused by intense incident radiation at Yunnan, as there was little difference in crop radiation use efficiency (RUE) between locations. Large leaf area index (LAI) was also suggested to be an important factor. Average nitrogen (N) accumulation over 2 years was 49% higher at Yunnan than at Kyoto, and also contributed to the large biomass accumulation at Yunnan. The treatments of varied N application for Takanari revealed that the ratio of N accumulated at maturity to the amount of fertilized N was significantly higher at Yunnan than at Kyoto, even though there was no great difference in soil fertility. The Takanari plot with high N application showed a N saturation in plant growth at Kyoto, which might be related to low radiation and relatively high temperatures during the mid-growth stage. These results indicate that the high potential yield of irrigated rice in Yunnan is achieved mainly by intense incident solar radiation, which caused the large biomass and the N accumulation. The low nighttime temperature during the mid-growth stage was also suggested to be an important factor for large biomass accumulation and high grain yield at Yunnan. 相似文献
106.
小菜蛾对4种农药抗药性的研究 总被引:4,自引:0,他引:4
用浸叶法测定了日本关西地区小菜蛾幼虫对乙酰甲胺磷、巴丹、氯氰菊酯和Bt4种不同类型农药的抗药性。试验明确小菜蛾在当地对上述4种参试农药都已产生不同程度抗药性。小菜蛾R系幼虫在240mg/kg氯氰菊酯、200μl/LBt浓度下死亡率分别仅为3.7%、7.2%。这两种农药目前已不能用于防治日本关西地区菜田小菜蛾 相似文献
107.
Kumiko Hayashi Kunihiko Konno Kyoko Adachi Takeshi Nawamura Yoshikazu Shizuri Yuji Okita Ikuo Kimura 《Fisheries Science》2009,75(3):797-803
Suppressive effects of neocarrabiose 4-O-sulfate on the thermal and freeze denaturation of myosin subfragment-1 (S-1) and on myofibrils were investigated. The compound
strongly suppressed the thermal denaturation of S-1. Its suppressive effect was greater than that of sorbitol and similar
to that of maltose. However, it tended to accelerate the denaturation of myofibrils, suggesting a loss of protection by F-actin
upon its addition. The compound suppressed the freeze denaturation of myofibrils and S-1. The effect was similar to that of
sorbitol or maltose, and completely different from that of Na-sulfate. The compound solubilized myofibrils at concentrations
similar to KCl. Therefore, it was concluded that neocarrabiose 4-O-sulfate behaved as an ionic salt in the thermal treatment process, whereas it behaved as a sugar in the frozen storage process. 相似文献
108.
Ryusuke Sudo Ryota Tosaka Shigeho Ijiri Shinji Adachi Hiroaki Suetake Yuzuru Suzuki Noriyuki Horie Satoru Tanaka Jun Aoyama Katsumi Tsukamoto 《Fisheries Science》2011,77(4):575-582
To improve understanding of the mechanism of early ovarian development in eels, the effects of water temperature decrease
on oocyte development, plasma levels of sex steroids [estradiol 17β (E2), testosterone (T), 11-ketotestosterone (11-KT)],
and gonadotropin β-subunit [follicle-stimulating hormone (FSHβ), luteinizing hormone (LHβ)] messenger RNA (mRNA) expression
levels were investigated. A total of 27 female Japanese eels Anguilla japonica were divided into initial, control, and test (water temperature decrease) groups. Starting on 22 September 2009, eels in
the test group were reared in a tank with gradual temperature decrease from 25°C to 15°C over 39 days, while the control group
was maintained at 25°C. The test group accumulated more oil droplets in their oocytes than did the other groups. Levels of
sex steroids, especially 11-KT, were higher in the test group. In contrast, FSHβ and LHβ mRNA expression levels were lower
in the test group. These results suggest that water temperature decrease only induced an early stage of ovarian development
that was partly affected by an 11-KT increase. For further maturation, other environmental factors related to induction of
gonadotropin increase appear to be needed. 相似文献
109.
Shuhei Tanaka Shin-ichiro Kochi Heigo Kunita Shin-ichi Ito Mitsuro Kameya-Iwaki 《European journal of plant pathology / European Foundation for Plant Pathology》1999,105(6):577-584
Flusulfamide (2, 4-dichloro-,,-trifluoro-4-nitro-m-toluenesulfonanilide) was investigated for its mode of action against Plasmodiophora brassicae Woronin. Seedlings of Chinese cabbage (Brassica rapa L. subsp. pekinensis) were grown for 14 and 21 days in soil infested with P. brassicae and then transplanted into soil containing flusulfamide (0.9µg a.i.g–1 dry soil). Clubroot was not suppressed by this treatment, indicating that the fungicide is ineffective against P. brassicae established within cortical cells of the host root. Where seedlings were grown in soil infested with resting spores which had previously been treated with flusulfamide, root-hair infection and club formation were suppressed. This indicates that flusulfamide directly acts against resting spores. When placed in root exudates of Chinese cabbage, untreated resting spores germinated at a high frequency while flusulfamide-treated resting spores hardly germinated at all. Use of the Evan's blue staining assay indicated that flusulfamide-treated resting spores remained viable. Flusulfamide was detected by high performance liquid chromatography on resting spores treated with flusulfamide for 30min. This indicates that the chemical is adsorbed onto resting spores. These results suggest that flusulfamide suppresses clubroot disease by inhibiting germination of P. brassicae resting spores through adsorption onto their cell walls. 相似文献
110.