Dual origin of the cultivated rice based on molecular markers of newly collected annual and perennial strains of wild rice species, Oryza nivara and O. rufipogon     

Shinsuke Yamanaka  Ikuo Nakamura  Hirokazu Nakai  Yo-Ichiro Sato 《Genetic Resources and Crop Evolution》2003,50(5):529-538

The direct ancestor of rice (Oryza sativa L.) is believed to be AA genome wild relatives of rice in Asia. However, the AA genome wild relatives involve both annual and perennial forms. The distribution of the retrotransposon p-SINE1-r2, a short interspersed nuclear element (SINE) at the waxy locus was analyzed in diverse accessions of the AA genome wild relatives of rice (O. rufipogon sensu lato). Most annual wild rice accessions had this retrotransposon, while most perennial types lacked this element, contradicting results to the previous studies. Results presented here suggest that O. sativa has dual origin that lead to indica-japonica differentiation. Results suggest the indica line of rice varieties evolved from the annual genepool of AA genome and the japonica varieties from the perennial genepool of AA genome wild rice.  相似文献   

2,4-Nonadienal and benzaldehyde bioantimutagens in Fushimi sweet pepper (Fushimi-togarashi)     

Nakamura Y  Suganuma E  Matsuo T  Okamoto S  Sato K  Ohtsuki K 《Journal of agricultural and food chemistry》1999,47(2):544-549

Fushimi sweet pepper, "Fushimi-togarashi", is one of the "Kyo-yasai", traditional vegetables, in Kyoto, Japan. The chloroform fraction of Fushimi sweet pepper showed bioantimutagenicity on UV induced mutation in Escherichia coli B/r WP2. The bioantimutagen was purified with silica gel chromatography and identified as 2, 4-nonadienal (ID(50) = 20 microg/plate) on the basis of GC retention time and EI-MS spectrum of authentic 2,4-nonadienal. The sweet pepper also contained a known bioantimutagen, benzaldehyde (ID(50) = 2 mg/plate). Additive bioantimutagenicity was also observed by 2, 4-nonadienal with benzaldehyde. 2,4-Nonadienal did not show bioantimutagenicity in an UV excision repair deficient strain, E. coli B/r WP2s uvrA(-)(). Furthermore no delay of the first cell division after UV irradiation was observed in E. coli B/r WP2. These results indicate that the bioantimutagenic activity of 2, 4-nonadienal on UV mutagenesis might depend on the excision repair system in E. coli B/r WP2.  相似文献   

Isolation and structural elucidation of some procyanidins from apple by low-temperature nuclear magnetic resonance     

Shoji T  Mutsuga M  Nakamura T  Kanda T  Akiyama H  Goda Y 《Journal of agricultural and food chemistry》2003,51(13):3806-3813

Procyanidin fractions from apple were separated according to the degree of polymerization using normal phase chromatography. Evaluation of physiological functionalities of procyanidins requires individual structural determination. However, it is difficult to elucidate the structure of procyanidins, in particular those with (+)-epicatechin (1) or (-)-catechin (2) units, and determine whether the interflavanoid bonds are 4beta-->8 or 4beta-->6 without cleavage and acetylation. Structural determination used LC-MS and low-temperature NMR. Nine procyanidins were separated by preparative HPLC consisting of three well-known procyanidins [procyanidin B1 (3), procyanidin B2 (4), and procyanidin C1 (5)] and six new procyanidins [epicatechin-(4beta-->8)-epicatechin-(4beta-->8)-catechin (6); epicatechin-(4beta-->6)-epicatechin-(4beta-->8)-catechin (7); epicatechin-(4beta-->6)-epicatechin-(4beta-->8)-epicatechin (8); epicatechin-(4beta-->8)-epicatechin-(4beta-->6)-catechin (9); epicatechin-(4beta-->8)-epicatechin-(4beta-->6)-epicatechin (10); and epicatechin-(4beta-->8)-epicatechin-(4beta-->8)-epicatechin-(4beta-->8)-epicatechin (11)]. Compounds 6-11 were detected for the first time as apple constituents.  相似文献   

Gas chromatographic determination with electron capture detection of residual ethylene oxide in intraocular lenses     

H Kikuchi  A Nakamura  K Tsuji 《Journal of the Association of Official Analytical Chemists》1988,71(5):1057-1062

A sensitive method is described to determine trace quantities of ethylene oxide (EO) in EO-sterilized intraocular lenses (IOLs). An IOL is dipped in ethanol containing 0.25 ppm propylene oxide (PO) in a 4 mL vial, 2 drops of freshly distilled hydrobromic acid is added through a septum, and the mixture is warmed at 50 degrees C for 24 h. It is then neutralized by vigorous shaking with sodium bicarbonate, dehydrated with anhydrous sodium sulfate, and filtered. The filtrate is injected into a gas chromatograph with electron-capture detection, and the peak height ratio of ethylene bromohydrin/propylene bromohydrin is measured. EO residue is calculated from the calibration curve obtained through a similar procedure with the standard EO/PO solutions. The limit of determination is 0.04 microgram/lens (ca 2.0 ppm). When EO residue levels were determined for IOLs sampled at 3 different aeration periods after sterilization, we found that 9 days of aeration was necessary to meet the U.S. Food and Drug Administration proposed limit for EO residue in IOLs.  相似文献   

Purification and characterization of polyphenol oxidase from banana (Musa sapientum L.) pulp   总被引：12，自引：0，他引：12  

Yang CP  Fujita S  Ashrafuzzaman M  Nakamura N  Hayashi N 《Journal of agricultural and food chemistry》2000,48(7):2732-2735

Polyphenol oxidase (EC 1.10.3.1, PPO) in the pulp of banana (Musa sapientum L.) was purified to 636-fold with a recovery of 3.0%, using dopamine as substrate. The purified enzyme exhibited a clear single band on polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE. The molecular weight of the enzyme was estimated to be about 41000 and 42000 by gel filtration and SDS-PAGE, respectively. The enzyme quickly oxidized dopamine, and its K(m) value for dopamine was 2.8 mM. The optimum pH was at 6.5, and the enzyme activity was stable in the range of pH 5-11 at 5 degrees C for 48 h. The enzyme had an optimum temperature of 30 degrees C and was stable even after a heat treatment at 70 degrees C for 30 min. The enzyme activity was completely inhibited by L-ascorbic acid, cysteine, sodium diethyldithiocarbamate, and potassium cyanide. Under a low buffer capacity, the enzyme was also strongly inhibited by citric acid and acetic acid at 10 mM.  相似文献   

Soil properties and the macrofauna community in abandoned irrigated rice fields of northeastern Argentina     

Patricia J. Folgarait  Fabien Thomas  Thierry Desjardins  Michel Grimaldi  Ichiro Tayasu  Pierre Curmi  Patrick M. Lavelle 《Biology and Fertility of Soils》2003,38(6):349-357

This study compared soil physical, chemical, and biological characteristics between natural grassland and recently abandoned rice fields in order to identify those variables that might explain the observed increase of Camponotus punctulatus anthills in abandoned rice paddy fields from Northern Argentina. Mainly due to a reduction of macropores and mesopores, overall porosity decreased by around 6% and bulk density was about 7% greater, in the 0- to 10- and 10- to 20-cm layers of the abandoned rice fields. Carbon and nitrogen content from organic matter increased (29% and 41% respectively for the 0- to 20-cm horizon) during cultivation but decreased (38% and 24%) 2 years after the last rice harvest. Forty percent of natural grassland-organic matter and 30% of abandoned rice-organic matter mineralized in less than 2 years. There was a different community structure between the abandoned rice fields and the undisturbed natural grassland and only a 20.6% (i.e. only 19 species from a total of 92) overlap in species composition. The abundance of macrofauna was greater in abandoned rice fields (2,208 individuals m^–2) in comparison to natural grasslands (288 ind m^–2) due to higher densities of small earthworms and Camponotus punctulatus ants; however, the Shannon index showed lower values in comparison to natural grasslands. Earthworms and C. punctulatus in the abandoned rice fields showed a change in their ¹³C signature indicating a switch in diet from natural grassland organic matter (C4) to organic matter from rice (C3). Our results indicate that the effects of rice cultivation practices did not seem to produce any physical or trophic limitations to recolonization by the macrofauna. It seems that changes in overall soil conditions have favored a change in the construction behavior of C. punctulatus which, in combination with population increases, could explain the explosion in number of anthills.  相似文献   

Genetic Erosion from Modern Varieties into Traditional Upland Rice Cultivars (Oryza sativa L.) in Northern Thailand     

R. Ishikawa  S. Yamanaka  Y. Fukuta  S. Chitrakon  C. Bounphanousay  K. Kanyavong  L.-H. Tang  I. Nakamura  T. Sato  Y.-I. Sato 《Genetic Resources and Crop Evolution》2006,53(2):245-252

The purpose of this study was to assess the extent of genetic erosion of traditional upland germplasm in northern Thailand as a result of gene-flow from distinct strains carrying different genotypes. Even modern variety specific markers have not been developed, there is a comparative population in Laos. Thus, both populations were compared with various characters to evaluate gene-flow from modern variety to landraces. Glutinous and glabrous strains are predominated in Laos. However, such strains were drastically decreased in north–east Thailand. Gene diversity is higher in Thailand, compared to Laos at seven isozyme loci. This was a result of the higher frequencies of Indica strains and heterozygotes in Thailand. Plastid type was also determined by using an INDEL marker. Nearly half of Indica strains carried the Japonica plastid. Heterozygotes also tended to carry Japonica cytoplasm. Such nuclear–cytoplasm substituted strains and heterozygotes were probably generated by natural hybridization. Japonica strains tended to be a maternal donor rather than Indica ones. Or Indica strains would easily release pollens, which grow outside of upland fields.  相似文献   

Pathological changes of tracheal mucosa in chickens infected with lentogenic Newcastle disease virus   总被引：1，自引：0，他引：1  

T Kotani  Y Odagiri  J Nakamura  T Horiuchi 《Avian diseases》1987,31(3):491-497

Forty-day-old specific-pathogen-free chickens were exposed by aerosol to lentogenic Newcastle disease virus (NDV) and observed for 24 days for pathological changes in the tracheal mucociliary system. Specific fluorescence of NDV antigen was observed through day 5 postexposure (PE) in the cytoplasm of the tracheal epithelium and desquamated epithelium in the lumen. On day 1 PE, scanning electron microscopy revealed hypertrophy of goblet cells and small patches of the deciliated epithelium scattered mainly around the openings of mucous glands. The deciliated area of tracheal surface increased through day 4 PE. Light microscopy showed small vacuoles containing lymphocytes and heterophils in the epithelial layer. Immature epithelium proliferated in some areas. On days 5 and 6 PE, ciliated areas of the trachea tended to increase as a result of regeneration of the epithelium, still leaving many nonciliated patches of various sizes. On and after day 8 PE, there remained plaques with nonciliated flat epithelium, but most areas were covered with well-ciliated epithelium. Non-ciliated plaques were observed until day 24 PE, but they gradually decreased in size. These plaques were covered by a single layer of flat epithelium and were formed upon lymph follicles in subepithelial tissue.  相似文献   

Escherichia coli multiplication and lesions in the respiratory tract of chickens inoculated with infectious bronchitis virus and/or E. coli.     

K Nakamura  J K Cook  J A Frazier  M Narita 《Avian diseases》1992,36(4):881-890

Escherichia coli numbers and histopathological changes were studied in the respiratory tract of line 151 chickens intranasally inoculated with infectious bronchitis virus (IBV) and/or virulent E. coli; this line is highly susceptible to IBV. Chickens inoculated with IBV alone showed increased numbers of E. coli in the trachea and had tracheitis, airsacculitis, and bronchiolitis. One of 17 chickens inoculated with IBV alone died with fibrinopurulent serositis. Chickens inoculated with IBV and E. coli had more severe and persistent respiratory lesions than those inoculated with IBV alone. E. coli was isolated from tracheas of chickens inoculated with IBV and E. coli more frequently than from chickens inoculated with IBV alone. In this group, 14 of 27 chickens died with tracheal plugs or with fibrinopurulent serositis. There was neither increased numbers of E. coli nor significant lesions in the respiratory tract of the group inoculated with E. coli alone. These results suggest that IBV may facilitate E. coli invasion into the lower respiratory tract of the chicken.  相似文献   

Watercore in Japanese pear. III. Changes in the activities of some enzymes relating to the degradation of cell walls and the accumulation of sugar     

Shohei Yamaki  Ichiro Kajiura  Mitsuo Omura  Koyu Matsuda 《Scientia Horticulturae》1977,6(1):45-53

The relationship between cellular breakdown and the activities of some cell-wall degrading enzymes (endocellulase, exocellulase, polygalacturonase, pectin methylesterase and β-galactosidase) was investigated in the watercored tissue of Japanese pear fruit, Pyrus serotina Rehder var. ‘Culta’ Rehder, cultivar ‘93-3’. In watercored tissue at an early stage, endocellulase activity, especially neutral form, was higher than that in healthy tissue. As the symptom of the watercore developed, polygalacturonase and β-galactosidase activities in the watercored tissue increased compared with those in healthy tissue. This indicated that in tissues at an early stage of watercore, these cell-wall degrading enzymes were activated, and operative in the breakdown of the cell wall. However, exocellulase and pectin methylesterase were not activated in the watercored tissue. The breakdown of cellular tissue was also supported by the fact that the DNA and protein contents decreased in the watercored tissue. Invertase activity decreased in the watercored tissue, compared with healthy tissue, and it was suggested that its decrease could be one of the causes of sucrose accumulation in the watercored tissue.  相似文献