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81.
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
82.
Kentaro Hayashi Takeshi Tokida Masako Kajiura Yosuke Yanai Midori Yano 《Soil Science and Plant Nutrition》2013,59(1):2-33
Croplands are an important source of atmospheric methane (CH4) and nitrous oxide (N2O), both potent greenhouse gases. Reduction of cropland CH4 and N2O emissions is expected to mitigate climate change. However, large uncertainty remains in the assessment and prediction of these emissions, which prevents us from establishing appropriate mitigation options and strategies. The uncertainty is attributed mainly to the high spatiotemporal variability in emissions (e.g., emission spikes of N2O). Understanding and quantifying how hotspots of CH4 and N2O production in soil and then hot moments of their emissions occur would help reduce the uncertainty. This review focuses on soil–plant systems, particularly the rhizosphere, as possible hotspots of production and consumption of CH4 and N2O. It is well known that the rhizosphere controls CH4 emission strongly, though each process of production and consumption remains to be quantified. On the other hand, surprisingly little attention has been paid to N2O, besides the fact that plant roots strongly control nitrification and denitrification. We review the current knowledge of cropland CH4 and N2O emissions, and conclude that soil–plant interactions strongly affect cropland emissions of both gases, in which functions of plant roots affecting biogeochemical factors (e.g., availability of oxygen, labile organic carbon and inorganic nitrogen) in the rhizosphere and phenological changes are particularly important. In relation to the status of current knowledge, we discuss future research needed. 相似文献
83.
Shohei Ogawa Takamitsu Tsukahara Takeshi Tsuruta Ryoichiro Nishibayashi Mie Okutani Masako Nakatani Kaya Higashide Shiori Iida Nobuo Nakanishi Kazunari Ushida Ryo Inoue 《Animal Science Journal》2014,85(6):678-682
Among domestic animals, teat order is only observed in the pig. In order to achieve the healthy growth and weaning of piglets, it is important to elucidate if volume of colostrum secretion and immunoglobulin A (IgA) and IgG concentrations differ among the teats of a sow. Nine sows were used to evaluate the difference in colostrum secretion volume (CSV) and four of these sows were assessed for IgA and IgG concentrations from each teat. Samples were collected five times during 21 h following parturition. Teats were assigned anatomical locations of teat (1 to 7) from anterior to posterior. The CSV of anterior (locations 1 and 2) and middle teats (locations 3–5) was significantly higher than those of posterior teats (locations 6 and 7) throughout the experiment except for 18 h post‐parturition (P < 0.05). The CSV of the teats at location 1 was significantly higher at most collection times than those at locations 6 and 7. A positive correlation of CSV was observed with IgA and IgG concentrations from 12 h and 6 h post‐parturition, respectively (P < 0.05). The results suggest that anterior teats secrete greater volumes of colostrum and that these tend to contain higher IgA and IgG than posteriors teats. 相似文献
84.
85.
Yuki Ichinose Fumiko Taguchi Masanobu Yamamoto Mayumi Ohnishi-Kameyama Tatsuo Atsumi Masako Iwaki Hiromi Manabe Mio Kumagai Quan Thanh Nguyen Chi Linh Nguyen Yoshishige Inagaki Hiroshi Ono Kazuhiro Chiku Tadashi Ishii Mitsuru Yoshida 《Journal of General Plant Pathology》2013,79(5):359-365
Glycosylation of flagellin is known to be involved in filament stabilization, motility, and virulence in Pseudomonas syringae. Here we investigated flagellin glycosylation in other phytopathogenic bacteria. Analyses of deduced amino acid sequences, glycostaining, and molecular masses of purified flagellins revealed that flagellins from all phytopathogenic bacteria investigated were glycosylated. Furthermore, the flagellin in a glycosylation-defective mutant of Xanthomonas campestris pv. campestris (Xcc) had a reduced molecular mass, and motility and virulence of the mutant toward host leaves decreased. These results suggest that flagellin glycosylation is ubiquitous in most phytopathogenic bacteria and that flagellin glycosylation is required for virulence in Xcc. 相似文献
86.
Karja NW Otoi T Murakami M Wongsrikeao P Budiyanto A Fahrudin M Nagai T 《The Journal of reproduction and development》2005,51(6):783-786
This study was conducted to improve parthenogenetic development in vitro of feline oocytes following a combined activation treatment of electrical stimulation and cycloheximide. In vitro matured (IVM) oocytes were stimulated electrically by a DC electrical pulse of 2 kV/cm for 50 micros. The stimulated oocytes were then incubated in MK-1 medium with or without cycloheximide and subsequently cultured in vitro for 6 days. No significant differences were observed between the two groups with respect to the proportions of cleavage, development to the morula stage, and the cell number of blastocysts. However, exposure of electrically stimulated oocytes to cycloheximide significantly increased the rate of development of the stimulated oocytes into the blastocyst stage compared with oocytes stimulated by electrical stimulation alone (31.0% vs 6.7%). The results from the present study suggested that a single electrical stimulation was insufficient to activate the IVM cat oocytes at 24 h of maturation and that exposure to cycloheximide following electrical stimulation improved the efficacy of the parthenogenetic development of domestic cat oocytes. 相似文献
87.
Fujimoto W Kimura K Suzuki M Syuto B Onuma M Iwanaga T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(3):291-294
Bovine gut chitinase is exclusively produced in the liver and secreted into the blood. In the present study, we established a semi-quantitative method by Western blot analysis for measurement of the chitinase content in blood and examined its alteration during postnatal development and experimental infection with hemoprotozoan parasite in cattle. Its serum levels from 1 week to 1 year of age showed a significant increase only in 3-4-month-old group. The plasma concentration of the gut chitinase was not changed during acute inflammation caused by lipopolysaccharide but increased gradually after a Theileria injection and peaked at 52 days post-infection. It appears that the increase in the blood chitinase levels might be a defensive response in cattle against protozoan infection. 相似文献
88.
Paddy herbicides contribute to the reduction of weeding labor, however, there are concerns about their effects on the environment and ecosystems. The environmental burden of applied herbicides is heaviest in water systems such as irrigation channels and rivers. Herbicides are generally detected in rivers in concentrations in levels of ng/L for only 2 to 3 months after use. It is to be regretted that herbicides have been implicated in accidents involving fish, the impeded propagation of algae and other non‐target organisms. Therefore, it is necessary to assess the ecological risk, and the Environment Agency in Japan compiled an interim report on how pesticides' ecological effects should be assessed. Pesticides are separately examined for their toxicity (hazard assessment) and exposure (exposure analysis). However, to the environment and ecosystems there are many problems in assessing the ecological risk of pesticides, such as selection of geographic locations, methodology of assessing the impacts on ecosystems and monitoring the effect of pesticides. New herbicides are expected to have high selectivity and low toxicity. Decreasing herbicide toxicity requires high selectivity to distinguish target weeds from crops and non‐target organisms. New groups of compounds will be developed based on a biorational approach. Moreover, it is necessary to develop an environmentally low‐impact application method such as the use of granular types and sustained‐release formulation among others. It is important that integrated methods be used to control paddy weeds by combining ecological/agronomical, mechanical and biological control methods, instead of relying solely on chemical herbicides. 相似文献
89.
Sato M Ohta R Kojima K Shirota M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(4):389-390
Two inbred strains of Hatano rats, which had been bred selectively on the basis for shuttlebox avoidance responses (high- and low-avoidance animals; HAA and LAA), were different in sperm motility. We have found that there are strain differences in the spontaneous incidence of sperm morphological abnormalities. The percentages of abnormalities were extraordinarily higher in the LAA rats, whose sperm motility was lesser. Since the high sperm abnormality was an exceptional case in rats, these rats may be useful models for sperm quality. 相似文献
90.