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101.
Alginate-coated meristems from in vitro-grown strawberry (Fragaria × ananassa Duch.) were successfully cryopreserved following
dehydration by a vitrification solution. Excised meristems from cold-hardened plantlets at 4 °C for two weeks in the dark
were encapsulated into alginate-gel beads containing a mixture of 2 M glycerol plus 0.4 M sucrose. These encapsulated and
cryoprotected meristems were dehydrated with a highly concentrated vitrification solution (designated PVS2) for 2 hr at 0
°C prior to a plunge into liquid nitrogen. Successfully encapsulated vitrified meristems remained green and then developed
shoots within one week after plating without intermediary callus formation. The average rate of shoot formation of encapsulated
vitrified meristems amounted to nearly 90%. The cryogenic protocol was successfully applied to four cultivars of strawberry.
It was also confirmed that encapsulated vitrified meristems cooled to - 196 °C produced higher shoot formation than encapsulated
dried meristems. Besides, the recovery growth was much earlier than the latter. The encapsulation-vitrification method is
easy to handle and produces high levels of shoot formation. Thus, the protocol promises for cryopreservation of strawberry
germplasm.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
102.
Proximate compositions and extractive components of the gonads (roes) of three species of sea urchins, namely, Diadema setosum, Salmacis sphaeroides and Toxopneustes pileolus, from the Gulf of Thailand were identified and the boiling effect on these extractive components of these sea urchin roes studied. Of the three species tested, the gonads of D. setosum had the lowest moisture (62 %) and ash (2 %) contents and the highest protein (15 %) and lipid (11 %) contents. Major extractive constituents of the roes of D. setosum were taurine, arginine, lysine, glycine, tyrosine, valine, leucine, isoleucine, alanine, glutamic acid and inosine 5′-monophosphate; those for the roes of S. sphaeroides were glycine, lysine, alanine, arginine, ATP and adenosine 5′-diphosphate; those for the roes of T. pileolus were glycine, alanine, serine, ATP and adenosine 5′-monophosphate, respectively. Boiling in 3 % brine (98–100 °C, 2 min) drastically reduced the amounts of both free amino acids and ATP-related compounds of sea urchins belonging to all these species. 相似文献
103.
Takashi Okayama Tooru Ooizumi Yoshiaki Akahane Sei-Ichi Kitakami Yo-Ichi Abe Jun Shirai 《Fisheries Science》2007,73(4):931-939
Changes in physical properties of two-step heated gels on addition of gluconate were investigated in terms of relationships
between breaking strength and gel stiffness. Regression lines between the breaking strength and the gel stiffness were extended
to the x-axis (gel stiffness), and the intercept was defined as SBSO. The SBSO of the two-step heated gels increased with gluconate contents in salt-ground surimis, suggesting that the harder but less elastic gels formed on addition of gluconate were dose-dependent. Conversely, the denaturation
rate constants of myosin in salt-ground surimis during preheating estimated by means of Ca-ATPase inactivation, loss of salt solubility, and decrease of denaturant solubility
were considerably reduced by gluconate. Thus, the progress of myosin denaturation was strongly suppressed. Increments of SBSO (δSBSO) of the two-step heated gels on addition of gluconate were inversely correlated with the denaturation rate constants of myosin
in salt-ground surimis for every index. Thus, the changes in physical parameters of two-step heated gel caused by gluconate may be associated with
the sluggish progress of myosin denaturation in salt-ground surimi during preheating. 相似文献
104.
Mitsuo Nakamura Tadahisa Seikai Masato Aritaki Reiji Masuda Masaru Tanaka Masatomo Tagawa 《Fisheries Science》2010,76(2):243-250
Flatfishes display a left–right asymmetry that is unique in the animal kingdom. In order to clarify the mechanisms of the
asymmetrical development of pigment cells, changes in pigment cell densities were examined in Japanese flounder Paralichthys olivaceus. During development from symmetrical larvae to asymmetrical juveniles, pigment cell densities were monitored on the skin
on both the left side (ocular side in juvenile; eventually has two eyes) and the right side (blind side in juvenile; eventually
has no eyes). A symmetrical and constant decrease was observed in leucophores and larval type melanophores. A mostly symmetrical
(slightly delayed on the blind side) and constant increase in iridophores from metamorphosis was observed. Adult-type melanophores
appeared and then increased only after metamorphosis on the ocular side. However, the pattern of xanthophores was complicated:
they first existed symmetrically and decreased symmetrically until metamorphosis, and they later increased only on the ocular
side. The dual appearance of the xanthophores, as well as the differences between their depths and sizes on the ocular and
blind sides, may suggest the presence of two types of xanthophores—just as melanophores are well known to exhibit two types.
The ontogenetic study of pigment cells described here is likely to help to elucidate the process of abnormal pigmentation
in flatfishes. 相似文献
105.
Predation on fish larvae by moon jellyfish <Emphasis Type="Italic">Aurelia aurita</Emphasis> under low dissolved oxygen concentrations 总被引:1,自引:0,他引:1
Jun?ShojiEmail author Reiji?Masuda Yoh?Yamashita Masaru?Tanaka 《Fisheries Science》2005,71(4):748-753
ABSTRACT: Laboratory experiments were conducted to test the hypothesis that low dissolved oxygen concentrations have the potential to enhance the predation rate on fish larvae by moon jellyfish Aurelia aurita which is increasing in abundance in the coastal waters of Japan. Larvae of the red sea bream Pagrus major in four size classes (2.9, 4.1, 6.2 and 8.6 mm in standard length) were used as prey in a short-term predation experiment. No change in the bell contraction rate of the jellyfish (mean bell diameter, 100.4 ± 10.2 mm) was observed at the oxygen concentrations tested (1, 2 and 4 mg/L, and air-saturated, 5.5–6.0 mg/L), suggesting a strong tolerance to a decline in the oxygen concentration. More than 80% of the 2.5 and 4.1-mm size-class larvae were predated on by the jellyfish at all oxygen concentrations during the 15-min trials in 10-L tanks. The 6.2 and 8.6-mm size-class larvae were able to escape from the jellyfish apparently due to their developed swimming ability at the two higher dissolved oxygen concentrations. There was an increase in predation on larvae of these two size classes at the two lower dissolved oxygen concentrations. Predation by moon jellyfish on fish larvae can be more intense at low dissolved oxygen concentrations that commonly occur in the coastal waters of Japan. 相似文献
106.
Methane uptake and nitrous oxide emission in Japanese forest soils and their relationship to soil and vegetation types 总被引:1,自引:1,他引:1
Tomoaki MORISHITA Tadashi SAKATA Masamichi TAKAHASHI Shigehiro ISHIZUKA Takeo MIZOGUCHI Yoshiyuki INAGAKI Kazuhiko TERAZAWA Satoshi SAWATA Masanori IGARASHI Hiroshi YASUDA Yasuhiro KOYAMA Yoshihito SUZUKI Nobuyuki TOYOTA Masamichi MURO Masaru KINJO Hirokazu YAMAMOTO Daitaro ASHIYA Yoichi KANAZAWA Tetsu HASHIMOTO Hidetaka UMATA 《Soil Science and Plant Nutrition》2007,53(5):678-691
107.
Toru TSUCHIDA Yoshihiko TAKAHASHI Norikuni OHTAKE Takuji OHYAMA Masaru KUBOTA 《Soil Science and Plant Nutrition》2006,52(1):133-133
(pp. 811–816)
The application method of liquid fertilizer with irrigation water was tested in large scale paddy fields using a newly developed fertilizer supplier which can make a supplying rate of liquid fertilizer constant. Uniformity of fertilization, change in the nitrogen concentration of flooded water and absorption of applied nitrogen by paddy rice were examined. High uniformity of fertilization was achieved with this method as compared with a conventional broadcast application of granular fertilizer, or an inflow fertilization of granule-like fertilizer with irrigation water.
When urea was applied as liquid fertilizer, the fertilizer-N disappeared quickly from ponding water under shallow conditions of ponding water depth. In the case of the same depth of ponding water, the rate of reduction was large under conditions of large permeability of water.
The nitrogen utilization rates of urea and ammonium sulfate labeled with15 N were not related to the depth of ponding water at the time of fertilization. When ammonium sulfate was supplied the nitrogen utilization rate was around 50% regardless of fertilization conditions however, the urea-N utilization rate fell to 40% or less at a permeability of ponding water of 0.8 cm day−1 or less, while it increased to 50% equivalent to ammonium sulfate, at 0.8 cm day−1 or more permeability. 相似文献
The application method of liquid fertilizer with irrigation water was tested in large scale paddy fields using a newly developed fertilizer supplier which can make a supplying rate of liquid fertilizer constant. Uniformity of fertilization, change in the nitrogen concentration of flooded water and absorption of applied nitrogen by paddy rice were examined. High uniformity of fertilization was achieved with this method as compared with a conventional broadcast application of granular fertilizer, or an inflow fertilization of granule-like fertilizer with irrigation water.
When urea was applied as liquid fertilizer, the fertilizer-N disappeared quickly from ponding water under shallow conditions of ponding water depth. In the case of the same depth of ponding water, the rate of reduction was large under conditions of large permeability of water.
The nitrogen utilization rates of urea and ammonium sulfate labeled with
108.
J Shirai K Nakamura M Narita K Furuta H Hihara H Kawamura 《The Veterinary record》1989,124(25):658-661
Avian nephritis virus, G-4260 strain, was inoculated orally into one-day-old specific-pathogen-free chicks of two lines. Approximately 20 per cent of the chicks of both lines died with visceral urate deposits from eight to 12 days after infection, and the virus was isolated from the kidneys of the dead chicks. At 14 or 15 days of age the mean liveweight of the surviving infected chicks was approximately 16 per cent less than that of the uninfected control chicks. 相似文献
109.
Jun Shoji Tsutomu Maehara Mitsuhiro Aoyama Hiroshi Fujimoto Akio Iwamoto Masaru Tanaka 《Fisheries Science》2001,67(2):238-245
SUMMARY: Diel successive samplings of Japanese Spanish mackerel Scomberomorus niphonius larvae were conducted throughout 24 h both in the sea and in captivity in order to estimate their daily ration. Using the Elliott and Persson model, the instantaneous gastric evacuation rate was estimated from the depletion of stomach contents (% dry bodyweight) with time during the night for wild fish (3.0–11.5 mm standard length) and from starvation experiments for reared fish (8, 10, and 15 days after hatching (DAH)). Japanese Spanish mackerel is a daylight feeder and exhibited piscivorous habits from first feeding both in the sea and in captivity. Feeding activity peaked at dusk. The estimated daily ration for wild larvae were 111.1 and 127.2% in 1996 and 1997, respectively; and those for reared larvae ranged from 90.6 to 111.7% of dry bodyweight. Based on the estimated value of daily rations for reared fish, the total number of newly hatched red sea bream Pagrus major larvae preyed by a Japanese Spanish mackerel from first feeding (5 DAH) to beginning of juvenile stage (20 DAH) in captivity was calculated to be 1139–1404. 相似文献
110.