Soft rot of root chicory in Hokkaido and its causal bacteria

In August 2010, bacterial soft rot was found on root chicory (Cichorium intybus var. sativum) in Hokkaido, Japan. Severely infected plants in fields were discolored, had wilted foliage, and black necrosis of petioles near the crown. Wilted leaves subsequently collapsed and died, forming a dry, brown or black rosette. The root and crown became partially or wholly soft-rotted. Slimy masses on infected areas of roots, turned dark brown or black. Gram-negative, rod-shaped, peritrichously flagellated, facultatively anaerobic bacteria were exclusively isolated from rotted roots, and typical symptoms were reproduced after inoculation with the strains. The bacteria were identified as Dickeya dianthicola, Pectobacterium carotovorum subsp. carotovorum, and Pectobacterium carotovorum subsp. odoriferum based on further bacteriological characterization and the sequence analysis of the malate dehydrogenase gene and 16S rRNA gene. These bacteria should be included with the previously reported Dickeya (=Erwinia) chrysanthemi in Saitama Prefecture, Japan, as causal pathogens of bacterial wilt of chicory.     

Evaluation of antixenosis in soybean against Spodoptera litura by dual-choice assay aided by a statistical analysis model: Discovery of a novel antixenosis in Peking

The method for evaluating soybean (Glycine max) antixenosis against the common cutworm (Spodoptera litura) was developed based on a dual-choice assay aided by a statistical analysis model. This model was constructed from the results of a dual-choice assay in which Enrei, a soybean cultivar susceptible to S. litura, was used as both a standard and a test leaf disc for 2nd–5th instar larvae. The statistical criterion created by this model enabled the evaluation of the presence of antixenosis. This method was applied to four soybean varieties, including Tamahomare (susceptible), Himeshirazu (resistant), IAC100 (resistant), and Peking (unknown), as well as Enrei. Subsequently, the degrees of antixenosis were also compared by F-test, followed by maximum likelihood estimation (MLE). According to the results, the antixenosis of Tamahomare, Himeshirazu, and IAC100 was statistically reevaluated and Peking exhibited a novel antixenosis, which was stronger for 3rd–5th instar larvae than for 2nd instar.     

Pathogenicity evaluation of Ralstonia pseudosolanacearum race 4 on ginger by leaf-clipping inoculation

Journal of General Plant Pathology - An easy, rapid method has been needed to test the pathogenicity of strains of Ralstonia pseudosolanacearum, the cause of serious bacterial wilt on ginger...     

Characterization of a nonfimbrial mannose-sensitive hemagglutinin (MSH) produced by Salmonella enterica serovar enteritidis

A nonfimbrial mannose-sensitive hemagglutinin (MSH) with adhesive properties produced by Salmonella enterica serovar Enteritidis was characterized. The MSH was characterized as glycoprotein and consisted of three noncovalently bound subunits of M_r 28, 33 and 40 kDa determined by SDS-PAGE. The hemagglutinin was heat-stable and resistant to alkaline (high) or acid (low) pH, however, it was inhibited by proteolytic enzymes, by EDTA and by sodium periodate. Mouse antiserum raised against MSH reacted with the 28 kDa band in immunoblotting, and also inhibited hemagglutination and bacterial adherence to HeLa cells. Electron microscope examinations showed that MSH is not a fimbriae-like structure. MSH and anti-MSH IgG competitively inhibited bacterial adherence to HeLa cells. The immunofluorescence test, using MSH on HeLa cells and specific anti-MSH IgG, supported the view that MSH contributes to adherence of the organism. These results indicate that MSH is a nonfimbrial putative adhesive factor that may mediate the adherence of Salmonella enteritidis to eucaryotic cells.     

The dynamics of antimicrobial-resistant Campylobacter jejuni on Japanese broiler farms

We investigated for dynamics of Campylobacter clones on 2 different managerial broiler farms. Campylobacter isolates were differentiated by resistance typing and molecular typing methods. On farm I, the same C. jejuni clones resistant to fluoroquinolone and oxytetracycline were isolated after one and half years again and another susceptible clone was invaded. The susceptible clone was isolated again after half year. Broiler flocks on the farm may be repeatedly infected with a few C. jejuni clones. On farm II, new clones including antimicrobial resistant one, were often invaded. The change of predominant C. jejuni clone in each flock on both the farms was observed, in the absence of antimicrobial selective pressure.     

Touchdown of the Hayabusa spacecraft at the Muses Sea on Itokawa

After global observations of asteroid 25143 Itokawa by the Hayabusa spacecraft, we selected the smooth terrain of the Muses Sea for two touchdowns carried out on 19 and 25 November 2005 UTC for the first asteroid sample collection with an impact sampling mechanism. Here, we report initial findings about geological features, surface condition, regolith grain size, compositional variation, and constraints on the physical properties of this site by using both scientific and housekeeping data during the descent sequence of the first touchdown. Close-up images revealed the first touchdown site as a regolith field densely filled with size-sorted, millimeter- to centimeter-sized grains.     

The rubble-pile asteroid Itokawa as observed by Hayabusa

During the interval from September through early December 2005, the Hayabusa spacecraft was in close proximity to near-Earth asteroid 25143 Itokawa, and a variety of data were taken on its shape, mass, and surface topography as well as its mineralogic and elemental abundances. The asteroid's orthogonal axes are 535, 294, and 209 meters, the mass is 3.51 x 10(10) kilograms, and the estimated bulk density is 1.9 +/- 0.13 grams per cubic centimeter. The correspondence between the smooth areas on the surface (Muses Sea and Sagamihara) and the gravitationally low regions suggests mass movement and an effective resurfacing process by impact jolting. Itokawa is considered to be a rubble-pile body because of its low bulk density, high porosity, boulder-rich appearance, and shape. The existence of very large boulders and pillars suggests an early collisional breakup of a preexisting parent asteroid followed by a re-agglomeration into a rubble-pile object.     

Development of an SSR marker set for efficient selection for resistance to black spot disease in pear breeding

Black spot disease, which is caused by Alternaria alternata (Fries) Keissler Japanese pear pathotype, is one of the most harmful diseases in Japanese pear cultivation. Because of the potential harm of fungicides to consumers and the environment, resistant cultivars are desired. In this study, to enable efficient marker-assisted selection in pear breeding, we conducted comprehensive inoculation tests and genotyping with 207 pear cultivars. We identified a marker set (Mdo.chr11.27 and Mdo.chr11.34) suitable for selection for black spot resistance. In most susceptible cultivars, Mdo.chr11.27 amplified a 220-bp band and Mdo.chr11.34 amplified a 259-bp band. The genotype of Mdo.chr11.34 corresponds perfectly to the estimated genotype of Japanese pears susceptible to black spot disease. Using linkage analysis, we identified the positions of the gene for susceptibility to black spot disease in Chinese pear. Mdo.chr11.27 and Mdo.chr11.34 were tightly linked to susceptibility in Chinese pear, and the susceptibility gene was mapped at the top of linkage group 11, similar to that in Japanese pear. This marker set and the accumulation of phenotypic data will enable efficient marker-assisted breeding for black spot resistance in pear breeding.     

Phytophthora blight of southern star (<Emphasis Type="Italic">Oxypetalum caeruleum</Emphasis>) caused by <Emphasis Type="Italic">Phytophthora palmivora</Emphasis> in Japan

In 2004, a damping-off symptom was found on southern star, Oxypetalum caeruleum, in Kochi Prefecture, Japan. Two Phytophthora strains with different colony patterns on potato dextrose agar were isolated, and their pathogenicity was confirmed by inoculation of southern star plants and their reisolation from symptomatic plants. Both fungi were identified as Phytophthora palmivora based on morphology, physiology, and sequence analysis of the internal transcribed spacers of nuclear ribosomal DNA. This is the first report of Phytophthora blight of southern star in the world.