Publications by authors named "Keiji Takasu"

Status of the current outbreak of cassava mosaic disease (CMD) in Southeast Asia was reviewed. Healthy cassava seed production and dissemination systems have been established in Vietnam and Cambodia, along with integrated disease and pest management systems, to combat the outbreak. Cassava (Manihot esculenta Crantz) is one of the most important edible crops in tropical and subtropical regions.

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Maternally inherited bacterial endosymbionts in arthropods manipulate host reproduction to increase the fitness of infected females. Cytoplasmic incompatibility (CI) is one such manipulation, in which uninfected females produce few or no offspring when they mate with infected males. To date, two bacterial endosymbionts, and , have been reported as CI inducers.

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We conducted a field study to determine seasonal egg parasitism rates of the kudzu bug Megacopta cribraria (F.) on the kudzu plant, Pueraria montana (Lour.) Merr.

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We describe the synthesis and properties of oligonucleotides (ONs) containing biaryl units, which are composed of a bis(hydroxymethyl)benzene residue and a naphthalene or pyrene moiety. We found that by introducing the biaryl units into the ONs, the aromatic chromophores are suitably arrayed in the DNAs. Further, we succeeded in the detection of a single-base mismatch in RNA by using the ON containing the biaryl unit as a molecular beacon.

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This paper describes the synthesis and properties of a novel molecular beacon (MB) containing a benzene-phosphate backbone at its stem moiety. The fluorescence intensity of MBs was found to stabilize by the introduction of the benzene-phosphate backbone at its stem moiety. Furthermore, an MB containing the benzene-phosphate backbone was more resistant to DNase I (endonuclease) than an MB comprising natural DNA and 2'-O-methyl-RNA.

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Microplitis croceipes (Hymenoptera: Braconidae) is a larval parasitoid of Helicoverpa/Heliothis spp. In the course of mass rearing of M. croceipes, we found that females oviposited in the conspecific adults in rearing cages.

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Two laboratory experiments were conducted to examine the ovipositional preferences of the egg parasitoidOoencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) for parasitized and unparasitizedMegacopta punctatissimum Montandon (Hemiptera: Plataspidae). Females that had never oviposited or that had not oviposite for 3 days preferred recently parasitized hosts more than unparasitized hosts. The preference for recently parasitized hosts appeared to be mediated by the punctures in already parasitized hosts made by the ovipositor of the first female.

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