Editorial     

Ryo Kohsaka 《Journal of Forest Research》2015,20(5):421-422

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Production of 2n pollen of Asiatic hybrid lilies by nitrous oxide treatment   总被引：1，自引：0，他引：1  

Masako Akutsu  Satomi Kitamura  Ryo Toda  Ichiro Miyajima  Keiichi Okazaki 《Euphytica》2007,155(1-2):143-152

Tetraploid varieties of lilies have superior agronomic traits such as large flowers and resistance to physiological disorders. In the present study, we attempted to induce 2n pollen of Asiatic hybrid lilies by arresting the meiotic process with nitrous oxide (N₂O) gas. To determine which meiotic stage is optimal for induction of 2n pollen, plants with attached buds at different meiotic stages were treated with N₂O for 24 h in a pressure-tolerant cylinder. A few 2n pollen grains were induced using plants with anthers in prophase I, whereas mixed pollen grains of differing size were produced using plants undergoing meiotic metaphase predominantly in anthers. Although normal lily pollen grains are elliptical, nitrous oxide exposure induced giant pollen grains that appeared spherical. Flow cytometry analysis showed that the giant pollen grains were diploid. When mixed pollen that included normal and giant pollen was crossed to tetraploid cultivars, the resulting seedlings were tetraploid and aneuploid, indicating that the giant pollen grains were diploids that could generate tetraploid seedlings through fusion to diploid eggs supplied from a tetraploid female parent. Thus, treatment with N₂O is useful for the production of 2n lily pollen and may provide a new approach for tetraploid lily breeding.  相似文献   

Diallel analysis of floral morphology in radish (Raphanus sativus L.)     

Kiwa Kobayashi  Atsushi Horisaki  Satoshi Niikura  Ryo Ohsawa 《Euphytica》2007,155(1-2):153-165

Patterns of photoperiodic-response curve (PRC) of heading time in rice were examined using the five near-isogenic lines (NILs) of Taichung 65, in which insensitive alleles was replaced by photosensitive alleles through backcrossings. In the first experiment, the NILs showed the diversified patterns of PRC, depending on genotype, under the controlled conditions (9-, 10-, 12- and 14-h daylengths). In addition, the two NILs with different Se1 alleles showed the different patterns although they showed similar heading times under natural daylength (NDL) conditions. The cryptic difference gives some clues as to the relationship between the patterns and heading-time behaviors under NDL conditions. In the second experiment, behaviors of vegetative and reproductive developments under 20-h daylength condition with high- and low-nutrient conditions were examined to know whether or not they behave as expected from their PRC obtained in the first experiment. Under the extremely long-day condition, the photosensitive alleles brought about long-growth durations where the internal changes for senescence might drastically occur with increases of total number of phytomers (TNP) and decrease potentials for reproductive developments. The nutrient levels might not affect the pattern of internal changes but might affect TNP, depending on genotype, and as a result, the nutrient levels might bring about different developmental fates in the same genotype under the long-day condition. The present results suggest the importance of genotype-by-environment interaction in relation to the cryptic variation of PRC in rice.  相似文献   

Inter-accession variation in floral morphology in radish (Raphanus sativus L.)     

Kiwa Kobayashi  Atsushi Horisaki  Satoshi Niikura  Ryo Ohsawa 《Euphytica》2006,152(1):87-97

We investigated variation in floral morphology among 36 accessions of radish (Raphanus sativus L.). We found wide, continuous inter-accession variation in 15 traits related to the size of the floral organs and the stigma position relative to the anthers of long stamens. A principal-component analysis of the 15 floral traits also showed wide variation among accessions. A large proportion of this variation was accounted for by lengths of stamens and the petal tube. In addition, the phenotypic stabilities with respect to the macro-environment (as affected by different sowing dates) and the micro-environment (among the flowers within a plant) differed between traits. Correlation analyses using all traits suggest the existence of genetic linkages or pleiotropies among floral organs. Our results indicate that floral morphologies varied greatly among radish accessions and they could be affected by the macro- and micro-environment. To explore the relationship between floral morphology and pollination efficiency, we compared the number of pollen grains deposited on the stigmas in the presence and absence of insect pollinators using three accessions with very different floral morphology. Because an accession with a higher stigma position than anthers might avoid self-pollination and an accession with a large stigma size received more pollen grains, floral morphology may affect pollination efficiency. Because the effect of pollination efficiency on seed production is well known, our results suggest that radish floral morphology affects seed production through its effect on pollination efficiency.  相似文献   

Resistance of larches to bark stripping by sika deer in Hokkaido,northern Japan     

Ken?Orihashi  Ryo?Hiyama  Yasuo?KojimaEmail author  Minoru?Terazawa  Shigehiro?Kamoda  Hisatomi?Kasahara  Yasuo?Takahashi 《Journal of Forest Research》2003,8(4):317-320

Resistance of the Japanese larch (Larix kaempferi) (Lk), the Kurile larch (L. gmelinii var. japonica) (Lg), and their F₁ hybrid (Lg × Lk) to bark stripping by sika deer (Cervus nippon yesoensis) were studied in a forest in Hokkaido by cafeteria tests. Several sets of logs prepared from Lk, Lg, and Lg × Lk were fed to the deer. The stripped areas of logs significantly differed between the Lk/Lg set and the Lk/Lg × Lk set (P 0.05). The resistances of Lg and Lg × Lk to bark stripping was stronger than Lk. This result was similar to those of previous studies on gray-sided voles and mountain hares in Hokkaido.  相似文献   

Effects of elevated CO2 concentration on growth, annual ring structure and photosynthesis in Larix kaempferi seedlings   总被引：2，自引：0，他引：2  

Yazaki K  Ishida S  Kawagishi T  Fukatsu E  Maruyama Y  Kitao M  Tobita H  Koike T  Funada R 《Tree physiology》2004,24(9):951-959

We evaluated the effects of elevated carbon dioxide concentration ([CO2]) and two nutrient regimes on stem growth rate, annual ring structure and temporal variations in photosynthetic characteristics of seedlings of Japanese larch (Larix kaempferi (Lamb.) Carr.). Seedlings were grown in phytotron chambers in an ambient (360 ppm) or an elevated (720 ppm) [CO2] in two nutrient regimes for one growing season. Elevated [CO2] reduced stem height and increased stem basal diameter compared with ambient [CO2]. The effect of elevated [CO2] on growth tended to be greater at high-nutrient supply than at low-nutrient supply. Elevated [CO2] had no significant effect on ring width or the number of tracheids per radial file. There was no obvious difference in cell wall thickness or the relative area of the cell wall between seedlings grown in ambient or elevated [CO2]. Although growth in elevated [CO2] resulted in a slight increase in cell diameter, the increase had a relatively minor effect on the relative area of the cell wall. Net assimilation rate increased in response to elevated [CO2]; however, the increase in whole-crown photosynthetic rate (Total Agrowth) in seedlings in the elevated [CO2] treatment was minimal because of the smaller specific needle area and acclimation of the photosynthetic characteristics of the needles to the growth [CO2]. In conclusion, we observed no obvious enhancement in the capacity for carbon fixation in Japanese larch seedlings grown in the presence of elevated [CO2] that might be attributable to changes in stem growth. However, elevated [CO2] caused changes in the temporal pattern of stem growth and in some anatomical features of the tracheids.  相似文献   

Activated carbon sheet prepared from softwood acetic acid lignin     

Yasumitsu Uraki  Ryo Taniwatashi  Satoshi Kubo  Yoshihiro Sano 《Journal of Wood Science》2000,46(1):52-58

As an example of activated carbon (AC) moldings, AC sheets were prepared from thermoplastic acetic acid lignin by lamination. The resulting AC sheets are a new type of product that can be applied as water and air cleaners. Powdered softwood acetic acid lignin (SAL) was molded into sheets by a thermal pressing method. When the sheet was carbonized under a stream of nitrogen at 1000°C, it was deformed with expansion and contained much foam. The deformation during carbonization was suppressed by the addition of pulp to the lignin. A sheet prepared by mixing lignin with pulp was directly carbonized without thermostabilization. The carbonized sheet was activated with steam for 2h. The resulting AC sheet had adsorption properties, such as specific surface and iodine adsorption capacity, comparable to those of commercial AC powders or granules. Furthermore, the AC sheet had a larger capacity to adsorb methane than did the commercial AC powder. Therefore, SAL seems to be a promising source for the AC moldings.  相似文献   

Disease-dependent differently methylated regions (D-DMRs) of DNA are enriched on the X chromosome in uterine leiomyoma     

Maekawa R  Yagi S  Ohgane J  Yamagata Y  Asada H  Tamura I  Sugino N  Shiota K 《The Journal of reproduction and development》2011,57(5):604-612

Uterine leiomyoma is the most common benign tumor in women. Although responsible gene mutations have not been found in leiomyomas, they represent a progressive disease with irreversible symptoms. To characterize epigenetic features of uterine leiomyomas, the DNA methylation status of a paired sample of leiomyoma and normal myometrium was subjected to a microarray-based DNA methylation analysis with restriction tag-mediated amplification (D-REAM). In the leiomyoma, we identified an aberrant DNA methylation status for 463 hypomethylated and 318 hypermethylated genes. Although these changes occurred on all chromosomes, aberrantly hypomethylated genes were preferentially located on the X chromosome. Using paired samples of normal myometrium and leiomyoma from 6 hysterectomy patients, methylation-sensitive quantitative real-time PCR revealed 14 shared X chromosome genes with an abnormal DNA hypomethylation status (FAM9A, CPXCR1, CXORF45, TAF1, NXF5, VBP1, GABRE, DDX53, FHL1, BRCC3, DMD, GJB1, AP1S2 and PCDH11X) and one hypermethylated locus (HDAC8). Expression of XIST, which is involved in X chromosome inactivation, was equivalent in the normal myometrium and leiomyoma, indicating that the epigenetic abnormality on the X chromosome did not result from aberration of XIST gene expression. Based on these data, a unique epigenetic signature for uterine leiomyomas has emerged. The 14 hypomethylated and one hypermethylated loci provide valuable biomarkers for understanding the molecular pathogenesis of leiomyoma.  相似文献   

The biological activities of cardenolide triglycosides from stems, twigs, and leaves of Nerium oleander     

Yuhua Bai  Ming Zhao  Liming Bai  Ryo Hasegawa  Jun-ichi Sakai  Toshiaki Hasegawa  Tomokazu Mitsui  Hirotsugu Ogura  Takao Kataoka  Katsutoshi Hirose  Masayoshi Ando 《Journal of Wood Science》2011,57(1):56-65

Sixteen cardenolide triglycosides (1?C16) were isolated from stems, twigs, and leaves of Nerium oleander. Among them, 3??-O-(4-O-gentiobiosyl-d-diginosyl)-7??,8-epoxy-14-hydroxy-5??,14??-card-20(22)-enolide, named cardenolide B-3 (16), was isolated from natural sources for the first time. The in vitro anti-inflammatory activities of compounds 1?C16 were examined on the basis of inhibitory activity against the induction of intercellular adhesion molecule-1 (ICAM-1). Compounds 1?C5 were active at an IC50 value of less than 7 ??M. The cytotoxic activity of isolated compounds was evaluated against three human cell lines: normal human fibroblast cells (W-38), malignant tumor cells induced from WI-38 (VA-13), and human liver tumor cells (HepG2). Compounds 1?C5 were active toward WI-38 cells; compounds 1, 3, and 5 were active toward VA-13 cells; and compounds 1?C5 were active toward HepG2 cells at IC₅₀ values of less than 10 ??M. The multidrug-resistant (MDR) cancer-reversal activity of compounds 1?C16 was evaluated on the basis of the amount of calcein accumulated in MDR human ovarian cancer 2780AD cells in the presence of each compound. Compounds 13 and 14 showed significant effects on calcein accumulation.  相似文献   

A microfluidic device for conducting gas-liquid-solid hydrogenation reactions     

Kobayashi J  Mori Y  Okamoto K  Akiyama R  Ueno M  Kitamori T  Kobayashi S 《Science (New York, N.Y.)》2004,304(5675):1305-1308

We have developed an efficient system for triphase reactions using a microchannel reactor. Using this system, we conducted hydrogenation reactions that proceeded smoothly to afford the desired products quantitatively within 2 minutes for a variety of substrates. The system could also be applied to deprotection reactions. We could achieve an effective interaction between hydrogen, substrates, and a palladium catalyst using extremely large interfacial areas and the short path required for molecular diffusion in the very narrow channel space. This concept could be extended to other multiphase reactions that use gas-phase reagents such as oxygen and carbon dioxide.  相似文献