FURTHER WORK ON SPECIES HYBRIDIZATION IN FRAGARIA AT BALSGÅRD

During 1993–1995 more than 700 cross combinations between different ploidy levels have been carried out. The emphasis has been to combine the excellent Fragaria vesca flavour with the commercial characters of F. x ananassa. Decaploid F. x vescana clones have been selected and are used together in an extensive crossing programme to improve the chances of obtaining superior new selections. So far only a few clones of near commercial quality have been found. The most promising is F9152003 [('Fern' x tetraploid F. vesca) x (F35084 x 'Honeoye')].

After backcrossing F. x vescana clones to F. x ananassa in two steps it has been possible to select octoploid clones which now are evaluated as donors of F. vesca characters to the octoploid level. Octoploid offspring have also been produced by crossing hexaploid F. vesca x F. x ananassa hybrids with the decaploid F. x vescana cultivar Sara.

The two species F. moschata (hexaploid) and F. viridis (diploid) each have interesting fruit flavour and are also included in the hybridization programme. Penta-and hexaploid hybrids between F. x ananassa and viridis have been produced for backcrosses to F. x ananassa. To combine the F. moschata characters with F. x ananassa direct hybridization has resulted in heptaploid hybrids which have been backcrossed to F. x ananassa. Several BC₁-seedlings have been used in second backcrosses. Offspring have also been obtained between the decaploid F. x vescana clone Sara and F. moschata.

Download Adobe Acrobat Reader (free software to read PDF files)