title: Fine mapping of the gene for susceptibility to black spot disease in Japanese pear (Pyrus pyrifolia Nakai).
abstract: Black spot disease, which is caused by the Japanese pear pathotype of the filamentous fungus Alternaria alternata (Fries) Keissler, is one of the most harmful diseases in Japanese pear cultivation. We mapped a gene for susceptibility to black spot disease in the Japanese pear (Pyrus pyrifolia Nakai) cultivar 'Kinchaku' (Aki gene) at the top of linkage group 11, similar to the positions of the susceptibility genes Ani in 'Osa Nijisseiki' and Ana in 'Nansui'. Using synteny-based marker enrichment, we developed novel apple SSR markers in the target region. We constructed a fine map of linkage group 11 of 'Kinchaku' and localized the Aki locus within a 1.5-cM genome region between SSR markers Mdo.chr11.28 and Mdo.chr11.34. Marker Mdo.chr11.30 co-segregated with Aki in all 621 F1 plantlets of a 'Housui' × 'Kinchaku' cross. The physical size of the Aki region, which includes three markers (Mdo.chr11.28, Mdo.chr11.30, and Mdo.chr11.34), was estimated to be 250 Kb in the 'Golden Delicious' apple genome and 107 Kb in the 'Dangshansuli' Chinese pear genome. Our results will help to identify the candidate gene for susceptibility to black spot disease in Japanese pear.
authors.affiliation: NARO Institute of Fruit Tree Science , Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Terakami
authors.affiliation: Apple Research Station, NARO Institute of Fruit Tree Science , Shimokuriyagawa, Morioka, Iwate 020-0123 , Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Moriya
authors.affiliation: Okitsu Citrus Research Station, NARO Institute of Fruit Tree Science , Shimizuokitsunaka-cho, Shizuoka, Shizuoka 424-0292 , Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Adachi
authors.affiliation: NARO Institute of Fruit Tree Science , Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kunihisa
authors.affiliation: NARO Institute of Fruit Tree Science , Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Nishitani
authors.affiliation: NARO Institute of Fruit Tree Science , Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Saito
authors.affiliation: Apple Research Station, NARO Institute of Fruit Tree Science , Shimokuriyagawa, Morioka, Iwate 020-0123 , Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Abe
authors.affiliation: NARO Institute of Fruit Tree Science , Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Yamamoto
keywords: Alternaria alternata; Pyrus pyrifolia; black spot disease; comparative genomics; fine mapping