Observation of the Disomic Inheritance of Four Allelic Pairs in the Octoploid Cultivated Strawberry

Although recent genetic studies suggest that octoploid cultivated strawberry, Fragaria ×ananassa Duch., is highly diploidized, there have been no reports that directly and clearly described the behavior of four allelic pairs. In this study, we demonstrated the disomic inheritance of four allelic pairs in F. ×ananassa by using two highly polymorphic simple sequence repeat markers. By genotyping the offspring of ‘Summer-princess’ (containing eight distinct alleles of marker FxaHGA02P13) × ‘Dekoruju’ (containing another four distinct alleles for this marker), four allelic pairs could be identified in ‘Summer-princess’. In a similar way, four allelic pairs could be identified for cultivar Ohishi-shikinari and marker EMFvi136. The results of this study provide direct evidence that at least part of the octoploid strawberry genome is fully diploidized and that the genome composition hypothesis AAA′A′BBB′B′ is possible as suggested by other recent genetic studies.