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21.
We assessed whether rolling damage by grazing horses could be reduced by constructing areas assigned for rolling. A group of horses were enclosed in a paddock with and without rolling areas made of dry soil, sand, and straw. Their behavior was recorded for 1 week in the paddock without any treatment (control paddock). Then the horses were moved to another paddock with the rolling areas (rolling paddock). After a 3-week familiarization period, horses were observed for 1 week. In the rolling paddock, the frequency and time spent rolling were significantly greater in rolling areas than in nonrolling areas. Horses significantly preferred the soil rolling area than sand and straw (P < .05). Although rolling was considered the most relevant body care behavioral element, the effects of the substrate in rolling areas on other body care behavioral activities, such as mutual and self-grooming, also were investigated. The frequency and duration of mutual grooming and the duration of self-grooming decreased significantly in the rolling paddock compared with the control paddock (P < .05). Hence, offering a rolling area encourages horses to roll in these areas and keeps the pasture in good condition; therefore, grazing time can be increased, with less reliance on supplementary feed. 相似文献
22.
Kubo K Entani T Takara A Wang N Fields AM Hua Z Toyoda M Kawashima S Ando T Isogai A Kao TH Takayama S 《Science (New York, N.Y.)》2010,330(6005):796-799
Self-incompatibility in flowering plants prevents inbreeding and promotes outcrossing to generate genetic diversity. In Solanaceae, a multiallelic gene, S-locus F-box (SLF), was previously shown to encode the pollen determinant in self-incompatibility. It was postulated that an SLF allelic product specifically detoxifies its non-self S-ribonucleases (S-RNases), allelic products of the pistil determinant, inside pollen tubes via the ubiquitin-26S-proteasome system, thereby allowing compatible pollinations. However, it remained puzzling how SLF, with much lower allelic sequence diversity than S-RNase, might have the capacity to recognize a large repertoire of non-self S-RNases. We used in vivo functional assays and protein interaction assays to show that in Petunia, at least three types of divergent SLF proteins function as the pollen determinant, each recognizing a subset of non-self S-RNases. Our findings reveal a collaborative non-self recognition system in plants. 相似文献
23.
Satoshi SUGIMURA Ken-ichi YAMANAKA Manabu KAWAHARA Takuya WAKAI Masaki YOKOO Eimei SATO 《Animal Science Journal》2010,81(1):48-57
We investigated the effects of in vitro maturation duration and treatment with dibutyryl cyclic adenosine monophosphate (dbcAMP) on the blind enucleation efficiency and developmental competence of miniature pig somatic cell nuclear transfer (SCNT) embryos. Oocytes were cultured for 22 h in NCSU-23 medium with or without 1 mM dbcAMP and then additionally cultured in dbcAMP-free NCSU-23 for 14, 18, or 22 h. Regardless of dbcAMP treatment, the rate of nuclear maturation reached a plateau at 36 and 40 h. However, mitochondrial distribution, a marker for cytoplasmic maturation, differed between the dbcAMP-untreated oocytes at 36 h and dbcAMP-treated oocytes at 40 h. The metaphase II chromosomes were adjacent to the first polar body in 68.8% and 63.5% of the dbcAMP-untreated oocytes at 36 h and dbcAMP-treated oocytes at 40 h, respectively. Furthermore, the blind enucleation efficiency by removing a small volume of cytoplasm was significantly higher in the dbcAMP-untreated oocytes at 36 h (82.9%) and dbcAMP-treated oocytes at 40 h (89.9%) than other groups. The rate of blastocyst formation was highest in the dbcAMP-treated oocytes at 40 h. Hence, this study demonstrated that dbcAMP-treated early metaphase II oocytes are suitable for the production of miniature pig SCNT embryos. 相似文献
24.
Benito Heru Purwanto Ken-ichi Kakuda Ho Ando Jong Foh Shoon Yoshinori Yamamoto Akira Watanabe 《Soil Science and Plant Nutrition》2013,59(4):529-537
Sago palms (Metroxylon sagu Rottb.) growing on peat soils were found to grow more slowly and to show a lower production than palms growing on mineral soils. This difference was related to the physical and chemical constraints of peat soils, which include low bulk density, high acidity, and low N, P, K, Ca, Zn, and Cu levels. In coastal lowland peat soils, the distance from the sea has been found to be an important determinant of soil elemental composition. We predicted that a sufficient supply of N at the rosette stage would improve sago palm growth and that the availability of N in soil to which controlled release N fertilizer was applied might be higher than that in soil treated with soluble fertilizer. To investigate the changes in the nutrient composition of peat soils at various distances from the sea and the effect on sago palm growth, we studied sago palm areas in Indonesia and Malaysia. To observe the influence of N on the growth performance, we also conducted a fertilizer experiment on coastal lowland peat soil in Indonesia. Distance from the sea had no significant effect on the cation concentration in the soil solution (with the exception of Mg) or on the levels of soil-exchangeable cations. No significant differences were observed between the concentrations of exchangeable cations in surface peat soils and those in mature leaves. However, the concentrations of K, Na, and Ca in mature leaves increased significantly with their concentrations in the soil solution. This finding implies that the concentrations of cations in sago palm leaves depend directly on the concentrations of cations in the soil solution. No significant effect of N fertilizers on plant height and leaf formation was observed. N fertilizers applied twice a year did not affect appreciably the foliar concentration of N determined in December 1998 (5 months after the initial application) and December 1999. In June 2000, we detected a significantly higher concentration of N (p < 0.01) in young leaves of the palms treated with LP-100 or urea than in control leaves. However, no significant difference was detected between the LP-100 and urea treatments in the concentration of N in both mature and young leaves. This finding indicated that the concentration of N in sago palm leaves increased with the level of soil-applied N, regardless of whether N was applied as controlled release fertilizer or in the soluble form. We anticipate that a significant difference in the effects of these N fertilizers may occur during the next rainy season, when there should be a considerable loss of soluble N. 相似文献
25.
The effect of rice plant growth on the loss of basal nitrogen (N) through denitrification in the rhizosphere of subsurface soil was investigated by the 15N balance method. Labeled 15N was applied to the deep soil layer to distinguish between the N losses in the surface and subsurface soils. Denitrification in pots with whole plants (Control) was compared with that in pots with plants cut off at the base of the culm (Pcut) to evaluate the effect of plant growth on denitrification. The upward movement of the applied 15N from the deep soil was negligible. Thus, the amount of unrecovered 15N was equal to the amount of N lost through denitrification in the rhizosphere of the subsurface soil (20–150 mm soil depth). In the Control treatment, values of redox potential at 50 and 90 mm soil depths were negative throughout the experimental period. Therefore, it was assumed that the redox potential could not have been the limiting factor for the N loss through denitrification in this experiment. The α-naphthylamine-oxidizing activity of roots decreased drastically after the cutting treatment. The estimated amount of de nitrified 15N in the rhizosphere of the subsurface soil was significantly higher in the Pcut treatment than in the Control one at 30 and 40 d after transplanting (DAT), while it was comparable in the two treatments at 52 and 64 DAT. Since a greater amount of 15N loss was found to occur when there was no absorption of 15N by the plants, the absorption of 15N by plants may have contributed to the suppression of denitrification. The amount of immobilized 15N in the Control treatment was larger than that of the Pcut treatment throughout the experiment. N immobilization might have also contributed to the suppression of denitrification in the rhizosphere of the subsurface soil. 相似文献
26.
Cytological characteristics of microconidia of <Emphasis Type="Italic">Magnaporthe oryzae</Emphasis>
Izumi Chuma Takeshi Shinogi Naoki Hosogi Ken-ichi Ikeda Hitoshi Nakayashiki Pyoyun Park Yukio Tosa 《Journal of General Plant Pathology》2009,75(5):353-358
The inner cellular structure of microconidia of Magnaporthe oryzae was examined using fluorescent probes and electron microscopic techniques. The volume of the nucleus relative to the cell
was significantly larger in microconidia than in macroconidia or vegetative hyphae, similar to observations for spermatia
of other fungi. Selective fluorescent staining revealed that cytosolic RNA was less abundant in microconidia than in macroconidia
and germ tubes, suggesting that general metabolic activity in microconidia is low. Consistently, GFP expression driven by
the TrpC promoter was highly active during the formation of phialides and microconidia but gradually decreased as the microconidia
matured. Such data suggest that microconidia are in a quiescent or dormant state. 相似文献
27.
28.
Yosuke Iimura Madoka Yoshizumi Tomonori Sonoki Mikiko Uesugi Kenji Tatsumi Ken-ichi Horiuchi Shinya Kajita Yoshihiro Katayama 《Journal of Wood Science》2007,53(6):541-544
To assess the possible utility of a fungal gene for manganese-dependent peroxidase (MnP) produced by a transgenic plant in
phytoremediation, we transformed hybrid aspen with a chimeric gene for MnP. Our gene construct allowed expression of the gene
for MnP in plants and relatively high MnP activity was detected in the hydroponic medium in which roots of plants that expressed
the transgene had been cultured. Some of our transgenic plants were able to remove bisphenol A from the medium more efficiently
than wild-type plants. Our results demonstrate that, without any modification of the coding sequence, a chimeric gene for
fungal MnP can be expressed in a woody plant, with secretion of active MnP from roots into the rhizosphere. Our strategy suggests
new options using woody plants for phytoremediation. 相似文献
29.
Effect of melatonin injected into the third ventricle on growth hormone secretion in Holstein steers 总被引:1,自引:0,他引:1
Kasuya E Kushibiki S Sutoh M Saito T Ito S Yayou K Sakumoto R Hodate K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(10):1075-1080
The effects of melatonin (MEL) injection into the third ventricle (3V) on growth hormone (GH) secretion were investigated in conscious Holstein steers. A stainless steel cannula was stereotaxically implanted in the 3V based on the ventriculogram. In Exp. 1, three doses of MEL (100, 300 or 600 microg) were injected into the 3V through the cannula and the GH concentration after the injection was determined. In Exp. 2, intracerebroventricular (icv) and intravenous (iv) injections of MEL (100 microg) and GH-releasing hormone (GHRH; 0.25 microg/kg body weight), respectively, were performed simultaneously to examine the effect of MEL on GHRH-induced GH release. The icv injection of MEL significantly stimulated GH release at 100 microg. The increase in GH concentrations by 100 microg of MEL was persistent. Intravenous injection of GHRH dramatically increased GH release. The injection of MEL did not alter GHRH-induced GH release. These results suggest that MEL stimulates GH secretion possibly through the hypothalamus in cattle. 相似文献
30.