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31.
Toshisuke Maruyama Iwao Hashimoto Kazuo Murashima Hiroshi Takimoto 《Paddy and Water Environment》2008,6(4):355-362
Kahokugata Lake, a closed lake, has been subject to eutrophication. This research was conducted to clarify the actual phenomena
and evaluation of the discharges of N and P from paddy test fields in the lowlands into Kahokugata Lake. A comprehensive mass
balance of N and P was obtained from 4 years of study. About N, the mean value of harvested unhulled rice (79.9 kg/ha) was
greater than mean controlled release fertilizer inputs (56.7 kg/ha). Other inputs and outputs include N in atmospheric acid
deposition (21.4 kg/ha) and N fixation–denitrification (9.2 kg/ha). The rice straw recycled after harvest was balanced by
straw produced in the succeeding year. The runoff and percolation losses discharged into the lake was 11.3 kg/ha, (8.6% of
total inputs). Since the rice harvested was consumed domestically, which taking out from the farmland and, therefore, nitrogen
pollutant into the lake was becoming small, paddy rice at this site is considered an “anti-polluting, purifying or cleansing”
crop. The P content in harvested rice (39.4 kg/ha) was balanced by fertilizer inputs (36.4 kg/ha). Previous studies examining
inflow–outflow relationships without considering a comprehensive mass balance may lead to erroneous conclusions. Our findings
indicate paddy rice in lowlands could be an environmentally friendly crop and can play an important role in reducing pollution
of lakes, and therefore should be considered in land use planning. 相似文献
32.
33.
The rotifer Brachionus plicatilis requires vitamin B12 . Freshwater Chlorella , which is produced by traditional culture, cannot support rotifer growth under bacteria-free conditions. However, Chlorella enriched with vitamin B12 can support rotifer growth. To attain stable mass production of Brachionus , it is desirable to develop a food that can completely support growth of the rotifers. The authors cultured rotifers at experimental and mass culture scale with concentrated Chlorella vulgaris suspension enriched with vitamin B12 in their cells.
Chlorella suspensions were prepared containing different amounts of vitamin B12 in their cells, and rotifers were then cultured in 20 ml of the prepared suspensions. The highest rotifer yield was obtained from the group cultured with Chlorella containing more vitamin B12 in their cells. The suitable content of vitamin B12 in the concentrated Chlorella suspension commercially available for mass culture of the rotifer is considered to be 200 μg per 100 g dry matter of Chlorella . The amount of vitamin B12 necessary to produce one individual rotifer is calculated at 0.32 pg.
The authors conducted mass production of the rotifer with baker's yeast and refrigerated concentrated Chlorella containing vitamin B12 Rotifer culture with vitamin B12 was more stable and showed 1.3 times higher production than with normal Chlorella . 相似文献
Chlorella suspensions were prepared containing different amounts of vitamin B
The authors conducted mass production of the rotifer with baker's yeast and refrigerated concentrated Chlorella containing vitamin B
34.
This report describes the efficient plant regeneration of Chamaecyparis obtusa Sieb et Zucc. via somatic embryogenesis. Embryogenic cultures were initiated from megagametophytes containing immature zygotic embryos. Embryogenic cultures were maintained and proliferated by 2–3-week interval subcultures in medium supplemented with 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine. High maturation frequencies of cotyledonary embryos were obtained on maturation medium containing maltose, polyethylene glycol, activated charcoal, and abscisic acid. Somatic embryos germinated readily after transfer to plant growth regulator-free medium. Growth of regenerated emblings has been monitored in a greenhouse. 相似文献
35.
Photosynthetic acclimation of deciduous broad-leaved tree species was studied along a vertical gradient within the canopy of a multi-species deciduous forest in northern Japan. We investigated variations in (1) local light regime and CO2 concentration ([CO2]), and (2) morphological (area, thickness and area per mass), biochemical (nitrogen and chlorophyll concentrations) and physiological (light-saturated photosynthetic rate) attributes of leaves of seven major species on three occasions (June, August and October). We studied early successional species, alder (Alnus hirsuta (Spach) Rupr.) and birch (Betula platyphylla var. japonica (Miq.) Hara); gap phase species, walnut (Juglans ailanthifolia Carrière) and ash (Fraxinus mandshurica var. japonica Rupr.); mid-successional species, basswood (Tilia japonica (Miq.) Simonk.) and elm (Ulmus davidiana var. japonica (Rehd.) Nakai); and the late-successional species, maple (Acer mono Bunge). All but maple initiated leaf unfolding from the lower part of the crown. The [CO2] within the vertical profile ranged from 320-350 ppm in the upper canopy to 405-560 ppm near the ground. The lowest and highest ambient [CO2] occurred during the day and during the night, respectively. This trend was observed consistently during the summer, but not when trees were leafless. Chlorophyll concentration was positively related to maximum photosynthetic rate within, but not among, species. Leaf senescence started from the inner part of the crown in alder and birch, but started either in the outer or top portion of the canopy of ash, basswood and maple. Chlorophyll (Chl) to nitrogen ratio in leaves increased with decreasing photon flux density. However, Chl b concentration in all species remained stable until the beginning of leaf senescence. Maximum photosynthetic rates observed in sun leaves of early successional species, gap phase or mid-successional species, and late successional species were 12.5-14.8 micromol m(-2) s(-1), 4.1-7.8 micromol m(-2) s(-1) and 3.1 micromol m(-2) s(-1), respectively. 相似文献
36.
Micropropagation of Bolaina blanca (Guazuma crinita Mart.), a fast-growing tree in the Amazon region
Emilio Maruyama Katsuaki Ishii Isao Kinoshita Kihachiro Ohba Akira Saito 《Journal of Forest Research》1996,1(4):211-217
Rapid clonal propagation of Bolaina blanca (Guazuma crinita Mart.) was established by the subculturing of the shoot-tips from aseptically germinated seedlings on woody plant medium
(WPM) supplemented with trans-zeatin [trans-6-(4-Hydroxy-3-methylbut-2-enylamino)purine] (ZEA). After 45 days of culture,
a seven-fold multiplication rate was achieved on WPM containing 10 μM of ZEA. Obtained shoots were simultaneously elongated
and rooted on WPM containing 1 μM of kinetin [6-furfurylaminopurine] (KIN). After 60 days of culturing the growth of shoots
was evident, and high rooting percentages were obtained. The plantlets were transferred into pots with vermiculite and acclimatized
successfully in plastic boxes with transparent cover inside the growth cabinet. 相似文献
37.
Somatic embryogenesis in Pinus thunbergii was initiated from megagametophytes containing immature zygotic embryos. Embryogenic cultures were maintained and proliferated in medium supplemented with 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine. High maturation frequencies of somatic embryos were obtained on maturation media containing maltose, activated charcoal, abscisic acid, and polyethylene glycol as osmotic agent. The best result among the cell lines tested was achieved with the cell line T-205-3. More than 900 somatic embryos per petri dish, on average, were obtained after about 8 weeks of culture on maturation medium. Sixty percent of somatic embryos tested germinated after transfer to plant growth regulator-free medium and then 85% of them converted into plantlets. 相似文献
38.
Rui Kano Takayuki Yano Kota Nagamatsu Haruhiko Maruyama Hiroshi Kamata Atsuhiko Hasegawa 《Research in veterinary science》2009,87(1):64-66
The effect of down-regulation of Mcl-1 expression by small interfering RNA (siRNA) against the canine Mcl-1 gene on apoptosis was investigated by transfecting CF33 (canine mammary gland tumor cell line) with siRNA using cationic liposomes. The siRNA against canine Mcl-1 increased the rate of apoptotic cells and decreased the numbers of viable cells. Further, sequence-specific down-regulation of Mcl-1 expression was measured by real time-PCR and Western blot analysis. The siRNA directed against the Mcl-1 gene reduced both the mRNA and protein expression in the CF33. Our study suggests the importance of Mcl-1 in canine mammary tumors for inducing apoptosis and reinforces using Mcl-1 as a putative therapeutic target in canine mammary gland tumor. 相似文献
39.
Yokoyama E Shibusawa Y Maruyama S Katsube Y Mikami T 《Comparative immunology, microbiology and infectious diseases》2005,28(3):177-186
Inhibition of isolation of Listeria monocytogenes by bacteriocin-like substance (BLS)-producing Listeria innocua after enrichment culture was investigated. When 26 L. monocytogenes strains were examined in combination with eight L. innocua strains using the spot on lawn method, 52/208 (25.0%) combinations showed the growth inhibition of L. monocytogenes. When two Listeria species were cultured simultaneously in selective enrichment broth, inhibition of isolation of L. monocytogenes was observed in 12/52 of the combinations at 24h (23.1%), in 24/52 at 48h (46.2%) and in 30/52 (57.7%) after 7 days of incubation. The randomly amplified polymorphic DNA profiles showed no interstrain similarities between either strains of the BLS-producing L. innocua or the BLS-sensitive L. monocytogenes strains. Therefore inhibition by BLS-producing L. innocua of isolation of L. monocytogenes after enrichment culture is unlikely to be dependent upon a particular genetic profile. 相似文献
40.
Yokoyama E Saitoh T Maruyama S Katsube Y 《Comparative immunology, microbiology and infectious diseases》2005,28(4):259-268
The actual prevalence of Listeria monocytogenes from contents of swine cecum was investigated. The efficiency of Listeria enrichment broth (LEB) for isolation was examined by the recovery of artificially inoculated L. monocytogenes in contents of swine cecum. The numbers of organisms did not increase after 48 h incubation, but increased when the rapid decrease in pH of the LEB was adjusted. Between 1991 and 1993, 250 contents of swine cecum were examined for the prevalence of L. monocytogenes using LEB enrichment, either with or without pH adjustment. L. monocytogenes was isolated from 74 samples in 1993 with pH adjustment, however, no organisms were isolated in 1991 and 1992. It was suggested that the marked rise of the L. monocytogenes isolation was due to the spread of the organism among swine. Furthermore, 67 out of the 74 isolates were identified as 1/2c by serotyping. The serovar 1/2c strains showed genetic diversity by random amplified polymorphic DNA. 相似文献