东莞石马河沿岸土壤重金属污染及生态毒性研究   总被引：2，自引：0，他引：2  

高磊  陈建耀  王江  柯志庭  杨雪韵  清水裕太  朱爱萍 《土壤学报》2014,51(3):538-546

为研究河水-地下水交互作用对河流沿岸土壤环境质量的影响,以东莞石马河沿岸土壤为研究对象,采集沿岸距离河道不等的6个土壤剖面共31个土样,测定土壤重金属(As、Cd、Cr、Cu、Fe、Mn、Ni、Pb和Zn)含量和土壤水提取液对发光菌的抑制率。结果表明,Cd、Cu、Ni和Zn的含量分别为2.80~11.2mg kg-1、9.70~298mg kg-1、11.4~69.7mg kg-1和40.4~465mg kg-1;Cd的地累积系数为6.06,达到极度污染水平;土壤重金属污染的地累积系数排序为CdZnCuNiCrMnAsPbFe;重金属含量差异与土壤有机质(SOM)含量和土壤微粒组分(63μm)有关,Cr、Cu、Ni、Zn、Mn和Cr、Ni与SOM含量和微粒组分分别呈显著正相关(p0.05或p0.01);土壤剖面毒性单位(∑TU)评价结果为剖面S3S2SbS1S4Sa,其中剖面S3的值最大,为5.51,属于中毒;土壤水提取液对发光菌的抑制率为2.45%~16.5%,为无毒或低毒。  相似文献   

First isolation of rose yellow mosaic virus in Japan     

Ohata  Yuta  Nishio  Takeshi  Tsuda  Shinya 《Journal of General Plant Pathology》2021,87(5):295-299

Rose yellow mosaic virus, which belongs to the Roymovirus genus in the Potyviridae family, was isolated here in Japan from a rose cultivar, Irish Mist. The full-length genomic sequence was similar to a strain in Minnesota, United States, which was the first ever isolated, with 85% nucleotide and 94% amino acid sequence similarities. Unlike the Minnesota strain, which lacks 220 nt including the 6K1 protein region, the Japanese isolate contains this coding region, which is commonly found in those of the Potyviridae.

  相似文献   

Pneumocystis Pneumonia in a Thoroughbred Racehorse     

Takanori Ueno  Hidekazu Niwa  Yuta Kinoshita  Yoshinari Katayama  Seiji Hobo 《Journal of Equine Veterinary Science》2014

Pneumocystis pneumonia is an opportunistic respiratory infection that occurs in immunocompromised animals. In horses, pneumocystic pneumonia is observed mostly in foals and often progresses rapidly. Here, we report pneumocystic pneumonia in a Thoroughbred racehorse. A 3-year-old Thoroughbred racehorse colt had marked respiratory symptoms for 3 weeks and was unresponsive to antibiotic treatment. At necropsy, firm, tan, patchy lesions were scattered diffusely in the lungs. Microscopically, alveolar septa thickened by proliferation of collagen fibers and infiltration of inflammatory cells were observed. In the alveolar spaces, many brown-black yeast-like organisms similar to cystic forms of Pneumocystis carinii were recognized by staining with Gomori's methenamine silver. Bronchoalveolar lavage fluid (BALF) obtained before necropsy included macrophages engulfing the fungus bodies. Amplified products were obtained from BALF and lung tissue samples by Pneumocystis-specific nested PCR. Phylogenetic analysis based on the 18S rRNA gene sequence revealed that the P. carinii organism from BALF was related to the Pneumocystis spp. detected in other animals and was especially close to P. carinii derived from ferrets. This is a rare case of pneumocystic pneumonia in a colt with chronic pulmonary lesions.  相似文献   

Ultrasonographic imaging of abomasal curd in preruminant calves     

Miyazaki T  Miyazaki M  Yasuda J  Okada K 《Veterinary journal (London, England : 1997)》2009,179(1):109-116

The aim of this study was to determine whether ultrasonography could be used to evaluate curd formation in the abomasum of preruminant calves. Holstein-Friesian calves were fed one of three milk replacers: clotting (five calves), non-clotting (four calves) and pH-dependent clotting (clots form at pH 5.5, but not at pH 6.5; six calves). Ultrasonography was performed until 6h after feeding the milk replacers. In calves fed the clotting milk replacer, a large clot of curd was visualised by ultrasonography as a clearly outlined echogenic image and whey as an anechoic image. In calves fed the non-clotting milk replacer, abomasal contents were visualised as a uniform, entirely echogenic image, indicating the absence of curd formation. In calves fed milk replacer with pH-dependent clotting properties, several small curds and whey were visualised by ultrasonography. It was concluded ultrasonography can be used to visualise abomasal curd and to distinguish the presence and absence of curds in the abomasum of calves.  相似文献   

Spatiotemporal distribution of Flavobacterium psychrophilum and ayu Plecoglossus altivelis in rivers revealed by environmental DNA analysis     

Tenma  Hinako  Tsunekawa  Koki  Fujiyoshi  Riho  Takai  Hajime  Hirose  Masae  Masai  Nanami  Sumi  Kosuke  Takihana  Yuta  Yanagisawa  Sogen  Tsuchida  Kota  Ohara  Kenichi  Jo  Toshiaki  Takagi  Masaki  Ota  Akiko  Iwata  Hiroyoshi  Yaoi  Yuichi  Minamoto  Toshifumi 《Fisheries Science》2021,87(3):321-330

Outbreaks of bacterial cold-water disease (BCWD), caused by Flavobacterium psychrophilum, are widespread in Japan, especially among ayu Plecoglossus altivelis. There are few investigations of F. psychrophilum in river water, and its seasonal distribution has not been clarified. We aimed to identify the spatiotemporal dynamics of F. psychrophilum and ayu to provide information that is useful for establishing a countermeasure for BCWD. Quantitative analysis of environmental DNA (eDNA) was used to clarify the year-round dynamics of ayu and F. psychrophilum. We sampled river water from the Nagara and Ibi rivers in Japan, and conducted monthly water sampling and eDNA quantification. Changes in the eDNA concentration of ayu were consistent with the known life histories of the fish. There was a strong negative correlation between the eDNA concentration of F. psychrophilum and water temperature, suggesting a strong dependence of F. psychrophilum dynamics in the river on water temperature. Furthermore, relatively high eDNA concentrations were recorded for both organisms in early summer and fall, suggesting that ayu is infected with F. psychrophilum during these seasons when experiencing up- and downmigration, respectively.

  相似文献   

The dorsal aorta initiates a molecular cascade that instructs sympatho-adrenal specification     

Saito D  Takase Y  Murai H  Takahashi Y 《Science (New York, N.Y.)》2012,336(6088):1578-1581

The autonomic nervous system, which includes the sympathetic neurons and adrenal medulla, originates from the neural crest. Combining avian blood vessel-specific gene manipulation and mouse genetics, we addressed a long-standing question of how neural crest cells (NCCs) generate sympathetic and medullary lineages during embryogenesis. We found that the dorsal aorta acts as a morphogenetic signaling center that coordinates NCC migration and cell lineage segregation. Bone morphogenetic proteins (BMPs) produced by the dorsal aorta are critical for the production of the chemokine stromal cell-derived factor-1 (SDF -1) and Neuregulin 1 in the para-aortic region, which act as chemoattractants for early migration. Later, BMP signaling is directly involved in the sympatho-medullary segregation. This study provides insights into the complex developmental signaling cascade that instructs one of the earliest events of neurovascular interactions guiding embryonic development.  相似文献   

Calcium-sensitive extracellular poly(α-L-guluronate)lyase from a marine bacterium Pseudomonas sp. strain F6: Purification and some properties     

Masatoshi Miyazaki  Junko Obata  Yoshiko Iwamoto  Tatsuya Oda  Tsuyoshi Muramatsu 《Fisheries Science》2001,67(5):956-964

ABSTRACT: Poly(α- L -guluronate)lyase, as one of alginate lyases, was purified from the culture medium of a marine bacterium, Pseudomonas sp. strain F6, to an electrophoretically homogeneous state. The enzyme was shown to have a molecular mass of 36 kDa by sodium dodecylsulfate–polyacrylamide gel electrophoresis (SDS-PAGE), and was most active at around pH 7.5 and was stable between pH 6.5 and pH 8.5. In the thermal stability experiments, the enzyme's activity diminished through an intermediate state with increasing incubation temperatures and was finally lost when heated at 100°C for 15 min. The addition of hen egg-white lysozyme to the enzyme decreased thermal stability dramatically. The apparent retention of enzyme activity (approximately 50%) was observed after the addition of 6 M guanidine hydrochloride and 8 M urea. Enzyme activity was lost completely with 10 mMSDS, while the ordered structure, which is considered likely to be β-structure, was markedly created. The similar conformational feature has also been created in marine bacterial and mollusc enzymes and the β-structure is commonly observed in polyuronate lyases. The divalent cation (Ca²⁺) promoted the activity of the calcium chelator-treated enzyme significantly, suggesting that Ca²⁺ is involved in the formation of the active intermediate between the acidic uronate(s) and amino acid side-chain(s) of the enzyme.  相似文献   

Evolutionary autoploidy in the sweet potato (Ipomoea batatas (L.) Lam.) and its progenitors     

Ichizo Nishiyama  Tsukasa Miyazaki  Satoshi Sakamoto 《Euphytica》1975,24(1):197-208

Summary The role of polyploidy in the evolution of the sweet potato. I. batatas (2n=6x=90), became more clear in 1971 when wild species with 30, 60, and 90 chromosomes were discovered. These species, I. leucantha (2x), I. littoralis (4x) and I. trifida (6x), are the progenitors of the sweet potato (6x), in an autopolyploid series with doubling of the I. leucantha B genome.In the present study the hypothesis of the origin of the sweet potato was confirmed by comparative studies on some plant characters, sexual compatibility, and the behavior of artificial hexaploids produced from I. leucantha (2x) and I. littoralis (4x).Since induced hexaploid I. leucantha exhibits weak growth, a few multivalents are formed at meiosis in the sweet potato, and there are differences in morphological and physiological characteristics between the artificial hexaploids and I. batatas, raw autoploidy seems unlikely, but a balanced or diploidised autoploidy could have been achieved by genic and chromosomal changes in the course of evolution. However, there is still sufficient homology so that meiotic pairing occurs usually between regular partners but also between homoeologous chromosomes in a certain situation.  相似文献   

Successful interspecific hybridization between Cucumis sativus L. and C. hystrix Chakr.   总被引：13，自引：0，他引：13  

Jin-feng Chen  Jack E. Staub  Yosuke Tashiro  Shiro Isshiki  Sadami Miyazaki 《Euphytica》1997,96(3):413-419

Interspecific F₁ hybrids were obtained from a cross between Cucumis sativus L. (2n = 2x = 14) and C. hystrix Chakr. (2n = 2x = 24). Controlled crossing resulted in fruit containing embryos which were excised and rescued on a Murashige and Skoog solid medium. A total of 59 vigorous plants were obtained from a fruit containing 159 embryos (37.3% regeneration rate). Hybrid plants were morphologically uniform. The multiple branching habit, densely brown hairs (especially on corolla and pistil), orange-yellow collora, and ovate fruit of F₁ hybrid plants were similar to that of the C. hystrix paternal parent. While appearance of the first pistillate flower was more similar to that of C. sativus maternal parent than to C. hystrix, staminate flower appearance was mid-parent in occurence. The diameter and internode length of stem, shape and size of leaves and flowers were intermediate when compared to the parents. An elongated green, trilobate style/stigma which was not apparent in either parent was observed in staminate flowers of F₁ plants. Similarly, the style/stigma of pistillate flower of F₁ plants were longger when compared to their parents. The brown pubescence observed on pistillate flowers of the F₁ and C. hystrix was not observed on the C. sativus parent. The somatic chromosome number of F₁ plants was 19. Two morphologically distinct groups of chromosomes were observed in the F₁ hybrid; 7 relatively large chromosomes characteristic of C. sativus, and 12 smaller chromosomes characteristic of C. hystrix. Analysis of malate dehydrogenase isozyme banding patterns provided additional comfirmation of hybridity. Reciprocal crossing of F₁ plants to either parent and self-crossing indicated that the hybrids were male and female sterile. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Detection of QTLs for white-back and basal-white grains caused by high temperature during ripening period in japonica rice     

Takuya Wada  Katsunori Miyahara  Jun-ya Sonoda  Tadashi Tsukaguchi  Masayuki Miyazaki  Masao Tsubone  Tsuyu Ando  Kaworu Ebana  Toshio Yamamoto  Norio Iwasawa  Takayuki Umemoto  Motohiko Kondo  Masahiro Yano 《Breeding Science》2015,65(3):216-225

There is increasing evidence that global warming affects the development of rice. High temperatures during ripening increase the ratio of undesirable chalky grains followed by deteriorating grain appearance quality. In order to detect quantitative trait loci (QTLs) controlling the occurrence of white-back and basal-white chalky grains of brown rice, QTL analysis was performed using recombinant inbred lines derived from a cross between two strains, ‘Tsukushiroman’ (sensitive to heat stress) and ‘Chikushi 52’ (tolerant of heat stress). The F₇ and F₈ lines were exposed to heat stress during the ripening period in two locations, Fukuoka and Kagoshima, in Japan. QTLs for white-back grains and basal-white grains were detected on chromosomes 1, 3, and 8, and those for basal-white grains were detected on chromosomes 2, 3, and 12. QTLs on chromosome 8 for white-back grains were shared in the plants grown in both locations. Near-isogenic lines (NILs), which harbored a segment from ‘Chikushi 52’ on chromosome 8 with the genetic background of ‘Tsukushiroman’, showed relatively lower ratios of white-back grains than ‘Tsukushiroman’. Therefore, insertion of the ‘Chikushi 52’ genomic region of the QTL on chromosome 8 can improve the quality of rice when it is grown under heat stress conditions.  相似文献