SSR-tagged breeding scheme for allogamous crops: a trial in bunching onion (<Emphasis Type="Italic">Allium fistulosum</Emphasis>)     

Hikaru Tsukazaki  Ken-Ichiro Yamashita  Akio Kojima  Tadayuki Wako 《Euphytica》2009,169(3):327-334

In several autogamous and vegetatively propagated crops, DNA markers have been used for cultivar identification. However, allogamous crops such as bunching onion (Allium fistulosum L.) are recalcitrant to marker-aided cultivar identification, as well as hybrid seed purity tests, due to the high degree of genetic heterogeneity within each cultivar. To aid cultivar identification and ensure its accuracy in bunching onion, we proposed the “SSR-tagged breeding” scheme in our previous study. The feasibility of this scheme was investigated here using a landrace of bunching onion with two populations tagged with two or four selected SSR markers. Compared with a control population, no significant differences were detected in the agronomic traits of the SSR-tagged populations. The targeted SSR loci were genetically uniform within each population whereas other loci maintained high heterogeneity. These results demonstrate that the SSR-tagged breeding scheme, even with a very small number of markers, is efficient for the identification of newly bred cultivars, and consequently for F₁ purity tests, in allogamous crops in which inbreeding depression is as severe as in bunching onion.  相似文献   

The aging effects of water immersion treatments in wet-bending for standardized testing of wood panels     

Hiroki Norita  Yoichi Kojima  Shigehiko Suzuki 《Journal of Wood Science》2008,54(2):121-127

The durability of wood-based panels is one of the most important properties when they are used in residential construction. The main objectives of this study were to investigate the quantitative relationship between the Wet-bending A test and the Wet-bending B test, examine the aging effects of the treatments specified in the wet-bending methods, and discuss the relationship between wet-bending and outdoor aging tests conducted in Shizuoka, Japan. Wet-bending tests, internal bond tests after humidity treatment, and outdoor aging tests in Shizuoka were conducted using eight types of commercial wood-based panels. A linear relationship was found between the load-carrying capacity (LCC) from the Wet-bending A test and the LCC from the Wet-bending B test. The LCC from Wet-bending B could be obtained from LCC from Wet-bending A by multiplying it by 0.9, which may be applicable as a quantitative ratio of aging effects between the two. LCC for methylenediphenyl diisocyanate-bonded panels recovered to almost 100% of the initial strength. A certain relationship was found between the LCC after Wet-bending A and the LCC after a 1-year outdoor exposure in Shizuoka. Internal bond strength showed a good correlation between the JIS-A treatment and the 1-year outdoor exposure treatment.  相似文献   

Citrate-release-mediated aluminum resistance is coupled to the inducible expression of mitochondrial citrate synthase gene in Paraserianthes falcataria     

Osawa H  Kojima K 《Tree physiology》2006,26(5):565-574

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Characterization of macrolide-resistant Campylobacter coli isolates from food-producing animals on farms across Japan during 2004     

Harada K  Asai T  Kojima A  Sameshima T  Takahashi T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(10):1109-1111

We investigated the susceptibilities against 7 antimicrobial agents in Campylobacter jejuni and C. coli isolates from food-producing animals in 2004. In comparison with the results of past surveillance, no significant difference was observed in resistance rates against all of the antimicrobials tested in Campylobacter isolates. However, slight increase of erythromycin (EM) resistance was found in C. coli isolates from pigs. We examined the mutation of the 23S rRNA gene and their susceptibilities against azithromycin, tylosin, and lincomycin in 44 EM-resistant isolates and 28 susceptible isolates of porcine origin. All the EM-resistant isolates contained A2075G in the 23S rRNA gene and showed cross-resistance to azithromycin, tylosin, and lyncomycin.  相似文献   

Ectomycorrhizal Association Enhances Al Tolerance by Inducing Citrate Secretion in Pinus densiflora     

Ko Tahara  Mariko Norisada  Takeshi Tange  Hisayoshi Yagi  Katsumi Kojima 《Soil Science and Plant Nutrition》2005,51(3):397-403

To investigate the effects of ectomycorrhizal association on the aluminum (Al) tolerance of Pinus densiflora Sieb. & Zucc., seedlings with or without ectomycorrhizal association with the fungus Pisolithus tinctorius (Pers.) Coker & Couch were exposed to 1 mM Al. Association with P. tinctorius alleviated Al-induced inhibition of root elongation and biomass growth in the mycorrhizal seedlings. Secretion of malate and citrate, both low-molecular-weight organic acids that could detoxify Al by the formation of stable complexes, was investigated in P. tinctorius mycelia and in pine roots with and without P. tinctorius association. Citrate secretion from the P. tinctorius mycelia in vitro was stimulated by Al. Citrate secretion from the roots of the ectomycorrhizal seedlings was also stimulated by Al, but was not detected in the non-mycorrhizal seedlings. These results suggest that citrate secreted from the roots of the ectomycorrhizal seedlings was produced in the hyphae of P. tinctorius. Citrate secretion may play a role in enhancing the Al tolerance of host seedlings.  相似文献   

alpha-Klotho as a regulator of calcium homeostasis     

Imura A  Tsuji Y  Murata M  Maeda R  Kubota K  Iwano A  Obuse C  Togashi K  Tominaga M  Kita N  Tomiyama K  Iijima J  Nabeshima Y  Fujioka M  Asato R  Tanaka S  Kojima K  Ito J  Nozaki K  Hashimoto N  Ito T  Nishio T  Uchiyama T  Fujimori T  Nabeshima Y 《Science (New York, N.Y.)》2007,316(5831):1615-1618

alpha-klotho was identified as a gene associated with premature aging-like phenotypes characterized by short lifespan. In mice, we found the molecular association of alpha-Klotho (alpha-Kl) and Na+,K+-adenosine triphosphatase (Na+,K+-ATPase) and provide evidence for an increase of abundance of Na+,K+-ATPase at the plasma membrane. Low concentrations of extracellular free calcium ([Ca2+]e) rapidly induce regulated parathyroid hormone (PTH) secretion in an alpha-Kl- and Na+,K+-ATPase-dependent manner. The increased Na+ gradient created by Na+,K+-ATPase activity might drive the transepithelial transport of Ca2+ in cooperation with ion channels and transporters in the choroid plexus and the kidney. Our findings reveal fundamental roles of alpha-Kl in the regulation of calcium metabolism.  相似文献   

Decomposition activity of peat soils in geogenous mires in Sasakami, central Japan     

Akira Haraguchi  Chiaki Hasegawa  Akiko Hirayama  Hisaya Kojima 《European Journal of Soil Biology》2003,39(4):191-196

Decomposition rates of peat and cellulose, and oxygen consumption rates were studied in three minerotrophic peat mires in Sasakami, central Japan. These mires had differences in topography, pedology and hydrology. Two dominant vegetation types in each mire, a Sphagnum palustre–S. cuspidatum community and a Rhynchospora fauriei community, were selected as the decomposition study sites. The objective of this study was to examine how the environmental and vegetational differences in mires correlate with the activity of decomposition. Decomposition rates of peat and the rates of cellulolysis were studied in the field for 6 months. Oxygen consumption rates were measured in the field using a closed chamber equipped with an oxygen electrode. In situ peat decomposition rates showed significant differences among the three mires, whereas in situ cellulolysis rates showed significant differences between communities. Peat mass loss rates positively correlated with the nitrogen and carbon concentration of the peat. Cellulolysis rates positively correlated with the range of water table fluctuation. Oxygen consumption rates showed significant negative correlation with the averaged and minimum water table depth, and positive correlation with the range of water table fluctuation. There was a significant positive correlation between cellulolysis rates and oxygen consumption rates. These are useful parameters for evaluating how the decomposition activity in soil depends on the vegetation types and water conditions.  相似文献   

Bending strength and internal bond strength of wood-based boards subjected to various exposure conditions     

Hideaki Korai  Yoichi Kojima  Shigehiko Suzuki 《Journal of Wood Science》2015,61(5):500-509

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Isolation of 1,796 SSR clones from SSR-enriched DNA libraries of bunching onion (Allium fistulosum)     

Hikaru Tsukazaki  Tsukasa Nunome  Hiroyuki Fukuoka  Hiroyuki Kanamori  Izumi Kono  Ken-ichiro Yamashita  Tadayuki Wako  Akio Kojima 《Euphytica》2007,157(1-2):83-94

Bunching onion (Allium fistulosum L.) is one of the most important vegetables in Japan. To establish a genetic basis for molecular breeding of bunching onion, we isolated 1,796 simple sequence repeat (SSR) clones by large-scale sequencing of SSR-enriched genomic DNA libraries. Of these, 1,331 (74.1%) contained (GT) _n repeats (n > 5), while 314 (17.5%) were (GA) _n -containing clones. The average number of SSR repeats was 10.5 and 10.4 in the (GT) _n - and (GA) _n -containing clones, respectively. In a sample of five bunching onion inbred lines, an average of 3.2 alleles were detected in the 100 SSR loci investigated, with the polymorphic information content averaging 0.55. These results indicate that bunching onion SSRs are very rich sources of highly informative genetic markers.  相似文献   

Four glucosides ofp-hydroxyphenyl derivatives from birch leaves     

Yanbo Shen  Yasuo Kojima  Minoru Terazawa 《Journal of Wood Science》1999,45(4):332-336

The extractive of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves was investigated. Four glucosides ofp-hydroxyphenyl derivatives were isolated, and their structures were indentified as betuloside (I), 3,4-dihydroxy-propiophenone-3--d-glucopyranoside (II), salidroside (III), and arbutin (IV). Arbutin was newly found in the leaves of shirakamba.  相似文献