title: Inheritance of S(f)-RNase in Japanese apricot ( Prunus mume) and its relation to self-compatibility.
abstract: Self-compatible cultivars of Japanese apricot ( Prunus mume Shieb. et Zucc.), a tree species that normally shows S-RNase-based self-incompatiblity, have a horticultural advantage over self-incompatible cultivars. Inheritance of self-compatibility and a common S(f)-RNase allele that is observed in self-compatible cultivars was investigated using progenies from controlled crosses. Total DNAs were isolated from the parents and progenies of seven crosses that included at least one self-compatible cultivar as a parent. These DNAs were PCR-amplified with the Pru-C2 and PCE-R primer pair to determine S-haplotypes of the parents and progenies. A novel S-haplotype, S(8), was found. In all crosses examined, the S(f)-RNase gene was inherited from either the seed or pollen parent as a pistil S-allele in a non-functional S-haplotype. Self-compatibility of about 20 trees each from reciprocal crosses of 'Benisashi ( S(7) S(f))' and 'Shinpeidayu ( S(3) S(f))', and 26 selections from 16 different crosses was tested by pollination and pollen-tube growth studies. Cosegregation of the S(f)-RNase allele and self-compatibility was confirmed with all but selection 1K0-26 ( S(3) S(7)). Selection 1K0-26 ( S(3) S(7)) that originated from 'Benisashi ( S(7) S(f))' x 'Koshinoume ( S(3) S(f))' appeared to be self-compatible even without the S(f)-RNase allele. The possible role of pollen- S, a presumably existing pollen component of gametophytic self-incompatibility, is discussed.
authors.affiliation: Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan, rtao@kais.kyoto-u.ac.jp
authors.forename: R.
authors.initials: R
authors.lastname: Tao
authors.forename: T.
authors.initials: T
authors.lastname: Habu
authors.forename: A.
authors.initials: A
authors.lastname: Namba
authors.forename: H.
authors.initials: H
authors.lastname: Yamane
authors.forename: F.
authors.initials: F
authors.lastname: Fuyuhiro
authors.forename: K.
authors.initials: K
authors.lastname: Iwamoto
authors.forename: A.
authors.initials: A
authors.lastname: Sugiura