Reduction of resting spore density of Plasmodiophora brassicae and clubroot disease severity by liming     

Hiroharu Murakami  Seiya Tsushima  Yukiko Kuroyanagi  Yoshihiro Shishido 《Soil Science and Plant Nutrition》2013,59(5):685-691

Abstract

Relationships between the disease severity of clubroot caused by Plasmodiophora brassicae, the soil pH value and the concentration of exchangeable calcium associated with liming were investigated under controlled density of resting spores. Disease indices were lower in the plots treated with lime than in the control plots without lime application. The disease index was significantly lower when lime materials were mixed two weeks before sowing compared with four weeks before sowing. The reduction rate of the disease index was larger for a concentration of 2.0 g kg^?1 than 1.0 g kg^?1 of lime in soil. The density of the resting spores in soil at the time of sowing was significantly reduced by liming. The reduction rate was 17–31 % for calcium cyanamide, 12–29% for dolomite, and 20–39% for calcium carbonate compared with the control plot. It was suggested that the disease severity was influenced by both the soil pH and the content of exchangeable calcium in soil based on the analysis of covariance.  相似文献   

Effects of hairy vetch foliage application on nodulation and nitrogen fixation in soybean cultivated in three soil types     

Takashi Sato  Emiko Sato  Fumiaki Takakai  Tadashi Yokoyama  Yoshihiro Kaneta 《Soil Science and Plant Nutrition》2013,59(2):313-319

We investigated the effects of applying hairy vetch foliage on nodulation and atmospheric nitrogen (N₂) fixation in soybean cultivated in three soil types in pot experiments. Soybean plants were grown in Gley Lowland soil (GLS), Non-allophanic Andosol (NAS), and Sand-dune Regosol (SDR) with hairy vetch foliage application in a greenhouse for 45 days. In GLS, the nodule number was not influenced by the application, however, nodule dry weight and N₂ fixation activity tended to increase. In NAS and SDR, nodule formation was depressed by foliage application. Soybean plant growth was promoted in GLS and SDR but not in NAS. These promotive effects of hairy vetch foliage application on soybean plant growth in GLS were considered to be mainly caused by the increase in N₂ fixation activity of the nodules, whereas it was considered to be mainly caused by the increase in nitrogen uptake activity of the roots in SDR. The varying effects of hairy vetch foliage application on soybean nodulation may be due to soil chemical properties such as pH and cation exchange capacity, which are related to soil texture. Therefore, we conclude that it is important to use hairy vetch for soybean cultivation based on the different effects of hairy vetch on soybean plant growth in different soil types.  相似文献   

Reverted glutathione S-transferase-like genes that influence flower color intensity of carnation (Dianthus caryophyllus L.) originated from excision of a transposable element     

Masaki Momose  Yoshio Itoh  Naoyuki Umemoto  Masayoshi Nakayama  Yoshihiro Ozeki 《Breeding Science》2013,63(4):435-440

A glutathione S-transferase-like gene, DcGSTF2, is responsible for carnation (Dianthus caryophyllus L.) flower color intensity. Two defective genes, DcGSTF2mu with a nonsense mutation and DcGSTF2-dTac1 containing a transposable element dTac1, have been characterized in detail in this report. dTac1 is an active element that produces reverted functional genes by excision of the element. A pale-pink cultivar ‘Daisy’ carries both defective genes, whereas a spontaneous deep-colored mutant ‘Daisy-VPR’ lost the element from DcGSTF2-dTac1. This finding confirmed that dTac1 is active and that the resulting reverted gene, DcGSTF2rev1, missing the element is responsible for this color change. Crosses between the pale-colored cultivar ‘06-LA’ and a deep-colored cultivar ‘Spectrum’ produced segregating progeny. Only the deep-colored progeny had DcGSTF2rev2 derived from the ‘Spectrum’ parent, whereas progeny with pale-colored flowers had defective forms from both parents, DcGSTF2mu and DcGSTF2-dTac1. Thus, DcGSTF2rev2 had functional activity and likely originated from excision of dTac1 since there was a footprint sequence at the vacated site of the dTac1 insertion. Characterizing the DcGSTF2 genes in several cultivars revealed that the two functional genes, DcGSTF2rev1 and DcGSTF2rev2, have been used for some time in carnation breeding with the latter in use for more than half a century.  相似文献   

Translation of continuous artificial selection on phenotype into genotype during rice breeding programs     

Kenji Fujino  Yoshihiro Kawahara  Kanako O. Koyanagi  Kenta Shirasawa 《Breeding Science》2021,71(2):125

Understanding genetic diversity among local populations is a primary goal of modern crop breeding programs. Here, we demonstrated the genetic relationships of rice varieties in Hokkaido, Japan, one of the northern limits of rice cultivation around the world. Furthermore, artificial selection during rice breeding programs has been characterized using genome sequences. We utilized 8,565 single nucleotide polymorphisms and insertion/deletion markers distributed across the genome in genotype-by-sequencing for genetic diversity analyses. Phylogenetics, genetic population structure, and principal component analysis showed that a total of 110 varieties were classified into four distinct clusters according to different populations geographically and historically. Furthermore, the genome sequences of 19 rice varieties along with historic representations in Hokkaido, nucleotide diversity and F_ST values in each cluster revealed that artificial selection of elite phenotypes focused on chromosomal regions. These results clearly demonstrated the history of the selections on agronomic traits as genome sequences among current rice varieties from Hokkaido.  相似文献   

Pause on avian flu transmission research     

Fouchier RA  García-Sastre A  Kawaoka Y  Barclay WS  Bouvier NM  Brown IH  Capua I  Chen H  Compans RW  Couch RB  Cox NJ  Doherty PC  Donis RO  Feldmann H  Guan Y  Katz J  Klenk HD  Kobinger G  Liu J  Liu X  Lowen A  Mettenleiter TC  Osterhaus AD  Palese P  Peiris JS  Perez DR  Richt JA  Schultz-Cherry S  Steel J  Subbarao K  Swayne DE  Takimoto T  Tashiro M  Taubenberger JK  Thomas PG  Tripp RA  Tumpey TM  Webby RJ  Webster RG 《Science (New York, N.Y.)》2012,335(6067):400-401

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Recovery of leptospires from miniature pigs experimentally infected with Leptospira interrogans serovar Manilae strain UP-MMC under immunosuppressive conditions by dexamethasone     

Sakoda Y  Naito M  Ito M  Ito Y  Isoda N  Tanaka T  Umemura T  Kida H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(7):955-958

Leptospira interrogans serovar Manilae strain UP-MMC was inoculated into miniature pigs to assess its pathogenicity. Leptospires were recovered from the whole blood, kidneys, and livers in the acute phase without showing any clinical signs. Under immunosuppressive conditions by dexamethasone, leptospires were recovered from the kidneys and their genes were detected from the urine in the chronic phase. These results indicate that leptospires persisted in the kidneys until the chronic phase, and excretion of leptospires in the urine was enhanced under immunosuppressive conditions, resulting in horizontal transmission among pigs on farms.  相似文献   

Immuno-magnetic separation and agar layer methods for the isolation of freeze-injured Yersinia enterocolitica O:8 from water     

Koujitani E  Horisaka T  Nomura Y  Hara-Kudo Y  Okatani AT  Iwata T  Kumagai S  Hayashidani H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(3):195-199

To develop an effective method to isolate an injured pathogenic Yersinia enterocolitica O:8 organism from environmental samples, we compared the isolation of freeze-injured and non-injured Y. enterocolitica O:8 and found that the isolation was more successful when immuno-magnetic separation (IMS) with anti-Y. enterocolitica O:8 antibody was used. Plating onto cefsulodin-irgasan-novobiocin (CIN) agar and Virulent Yersinia enterocolitica (VYE) agar by means of the agar layer method was found to be effective in isolating the injured cells. The alkali treatment which is generally used for selective detection of Yersinia organism failed to isolate freeze-injured pathogenic Y. enterocolitica O:8 cells. Recovery methods without using the alkali treatment were superior for detecting freeze-injured Y. enterocolitica O:8. Our results demonstrate that the IMS and the agar layer methods should be used to isolate injured pathogenic Yersinia organisms from environmental samples such as water.  相似文献   

<Emphasis Type="Italic">Pythium</Emphasis> and <Emphasis Type="Italic">Phytophthora</Emphasis> species associated with root and stem rots of kalanchoe     

Hideki Watanabe  Yoshihiro Taguchi  Mitsuro Hyakumachi  Koji Kageyama 《Journal of General Plant Pathology》2007,73(2):81-88

Pythium and Phytophthora species were isolated from kalanchoe plants with root and stem rots. Phytophthora isolates were identified as Phytophthora nicotianae on the basis of morphological characteristics and restriction fragment length polymorphism (RFLP) analysis of the rDNA-internal transcribed spacer regions. Similarly, the Pythium isolates were identified as Pythium myriotylum and Pythium helicoides. In pathogenicity tests, isolates of the three species caused root and stem rots. Disease severity caused by the Pythium spp. and Ph. nicotianae was the greatest at 35°–40°C and 30°–40°C, respectively. Ph. nicotianae induced stem rot at two different relative humidities (60% and >95%) at 30°C. P. myriotylum and P. helicoides caused root and stem rots at high humidity (>95%), but only root rot at low humidity (60%).  相似文献   

Searching by Differential Display for New Genes Implicated in Induced Disease Resistance of Cucumber Treated with Acibenzolar-S-methyl     

Yoshihiro NARUSAKA  Mari NARUSAKA  Hideo ISHII 《Journal of General Plant Pathology》2001,67(3):207-211

Acibenzolar-S-methyl (ASM) is a chemical activator of systemic disease resistance in plants. In this study, we used differential display to identify ASM-inducible defense response genes involved in induced disease resistance. As a result, we cloned three ASM-inducible genes from cucumber, encoding a chitinase, a putative protein disulfide isomerase and a putative mitochondrial-protein-like protein. Expression of these genes was induced within 24 hr after treatment of cucumber leaves with ASM. These results suggest that differential display is a useful tool for understanding the mode of action of ASM and defense responses. Received 6 September 2000/ Accepted in revised form 11 April 2001  相似文献   

Coal fly ash–based synthetic aggregates as potential alternative container substrates for ornamentals     

Guttila Y. Jayasinghe  Yoshihiro Tokashiki  Makoto Kitou  K. Kinjo 《植物养料与土壤学杂志》2009,172(5):720-728

This research was carried out to study the characteristics and the potential utilization of coal fly ash–based synthetic aggregates (CSA) with oil palm waste as an alternative container substrate for ornamental‐plant production. CSA only, oil palm waste only, and two mixing ratios of CSA with oil palm waste at the ratio of 1:5 and 1:10 (V/V) were utilized under this study. Zeolite was utilized as a standard substrate to compare characteristics of other substrates. The physical and chemical properties of all substrates were characterized. Scanning electron microscopy (SEM) of coal fly ash and CSA were conducted in order to study the structural configuration of the CSA. Developed CSA gave an alkaline pH (9.82), high electrical conductivity (96.1 mS m^–1), high cation concentrations, high water‐holding capacity, and low bulk density (0.56 g cm^–3) compared to zeolite. Mixing of CSA with oil palm waste at the ratio of 1:10 gave enhanced physical and chemical properties such as bulk density (0.25 g cm^–3), particle density (1.76 g cm^–3), air space (20.6%), total pore space (85.8%), total water‐holding capacity (652 mL L^–1), pH (6.18), and electrical conductivity (42.4 mS m^–1), which were in the established ideal substrate range. Moreover, SEM study revealed that CSA is a dual‐composite material, which had well enmeshed coal–fly ash particles in the fibrous paper‐waste matrix creating porous spaces within the aggregate. The growth of French marigold (Tagetes patula), which is a popular ornamental plant in Japan, was assessed using these newly developed substrates. The mixing ratio of CSA and oil palm wastes at 1:10 reported the best maximum growth and yield parameters of French marigold, with increase in shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, plant height, and number of flowers per plant by 51%, 93%, 54%, 150%, 19%, and 61%, respectively, compared to the zeolite. It is revealed that a mixture of CSA and oil palm waste at the ratio of 1:10 can be successfully utilized as an alternative container substrate for French marigold production.  相似文献