title: Detection of Self Incompatibility Genotypes in Prunus africana: Characterization, Evolution and Spatial Analysis.
abstract: In flowering plants, self-incompatibility is an effective genetic mechanism that prevents self-fertilization. Most Prunus tree species exhibit a homomorphic gametophytic self-incompatibility (GSI) system, in which the pollen phenotype is encoded by its own haploid genome. To date, no identification of S-alleles had been done in Prunus africana, the only member of the genus in Africa. To identify S-RNase alleles and hence determine S-genotypes in African cherry (Prunus africana) from Mabira Forest Reserve, Uganda, primers flanking the first and second intron were designed and these amplified two bands in most individuals. PCR bands on agarose indicated 26 and 8 different S-alleles for second and first intron respectively. Partial or full sequences were obtained for all these fragments. Comparison with published S-RNase data indicated that the amplified products were S-RNase alleles with very high interspecies homology despite the high intraspecific variation. Against expectations for a locus under balancing selection, frequency and spatial distribution of the alleles in a study plot was not random. Implications of the results to breeding efforts in the species are discussed, and mating experiments are strongly suggested to finally prove the functionality of SI in P. africana.
authors.affiliation: National Forestry Resources Research Institute, Mukono, Uganda.
authors.forename: Judith Ssali
authors.initials: JS
authors.lastname: Nantongo
authors.affiliation: Makerere University, Kampala, Uganda.
authors.forename: Gerald
authors.initials: G
authors.lastname: Eilu
authors.affiliation: Austrian Federal Office and Research Centre for Forests (BFW), Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Geburek
authors.affiliation: Austrian Federal Office and Research Centre for Forests (BFW), Vienna, Austria.
authors.forename: Silvio
authors.initials: S
authors.lastname: Schueler
authors.affiliation: Austrian Federal Office and Research Centre for Forests (BFW), Vienna, Austria.
authors.forename: Heino
authors.initials: H
authors.lastname: Konrad
mesh_terms: D019143:Evolution, Molecular; D017343:Genes, Plant; D014644:Genetic Variation; D005838:Genotype; D007438:Introns; D000068218:Prunus africana / Q000235:genetics* / Q000502:physiology; D060436:Self-Incompatibility in Flowering Plants