|Budget Amount *help
¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 1998 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Fiscal Year 1997 : ¥2,200,000 (Direct Cost : ¥2,200,000)
Wolbachia infection in 326 populations (including 10 populations from abroad) of 20 mite species was assayed by the polymerase chain reaction (PCR), using the 16S rDNA and the ftsZ primers which amplify 890-bp and 770-bp segment, respectively. Wolbachia were detected in 55 populations of 4 species : i.e., the green and red forms of Tetranychus urticae, T.kanzawai, T.pueraricola and Panonychus mori. Of them, Wolbachia that infects four populations of P.mori was related to reproductive incompatibility. Other populations appeared to harbor a neutral strain of Wolbachia that does not cause incompatibility. It is likely that infection with a neutral strain is not unusual in mites.
Out of five populations of P.mori that infected with Wolbachia, the Tsuruoka (TR), Toyama (TY), Hanayama (HN) and Haruno (HR) populations harbored Wolbachia that mediates reproductive incompatibility, while the Sendai (SD) population infected with a neutral strain. For example, unidirectional incompatibility has been observed m crosses between the Wolbachia-free Ami (AM) population and either of the TR or TY populations. As crosses between females from the AM population and rifampicin-treated males from either of the TR or TY populations restored compatibility, Wolbachia could have been responsible for the incompatibility.