title: Physical mapping of black spot disease resistance/susceptibility-related genome regions in Japanese pear (Pyrus pyrifolia) by BAC-FISH.
abstract: Black spot disease, caused by Alternaria alternata Japanese pear pathotype, is one of the most harmful diseases in Japanese pear cultivation. In the present study, the locations of black spot disease resistance/susceptibility-related genome regions were studied by fluorescence in situ hybridization using BAC clone (BAC-FISH) on Japanese pear (Pyrus pyrifolia (Burm. f.) Nakai) chromosomes. Root tips of self-pollinated seedlings of 'Osa Gold' were used as materials. Chromosome samples were prepared by the enzymatic maceration and air-drying method. The BAC clone adjacent to the black spot disease-related gene was labeled as a probe for FISH analysis. Black spot disease-related genome regions were detected in telomeric positions of two medium size chromosomes. These two sites and six telomeric 18S-5.8S-25S rDNA sites were located on different chromosomes as determined from the results of multi-color FISH. The effectiveness of the physical mapping of useful genes on pear chromosomes achieved by the BAC-FISH method was unequivocally demonstrated.
authors.affiliation: Faculty of Agriculture, Kagoshima University , Korimoto, Kagoshima 890-0065 , Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: NARO Institute of Fruit Tree Science , Fujimoto, Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Terakami
authors.affiliation: NARO Institute of Fruit Tree Science , Fujimoto, Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Takada
authors.affiliation: NARO Institute of Fruit Tree Science , Fujimoto, Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Yamamoto
keywords: Alternaria; bacterial artificial chromosome; chromosome; disease resistance; fluorescence in situ hybridization