PROTOPLAST FUSION AND ITS POTENTIAL ROLE IN THE GENETIC IMPROVEMENT OP ROSES

The fusion of callus-derived protoplasts from various cultivars of roses (Rosa hybrida ‘Frensham’) was induced using polyethylene glycol.
These protoplasts were fused either with protoplasts from cherry (Prunus avium x pseudocerasus ‘Colt’) or blackberry (Rutus laciniatus ‘Thornless Oregon’). Rosa persica x xanthina was self-fused and tetraploid plants were obtained.
These tetraploids exhibited unusual morphology, contained a chromosome complement of 28 which is double the diploid number for this hybrid, and had significantly increased guard cell lengths and chloroplast numbers.
Putative somatic hybrid plants involving either ‘Frensham’ and blackberry, or ‘Frensham’ and cherry, have also been regenerated.
Of the two parents, these plants appeared most like ‘Frensham’ but with several distinct morphological differences.
Root tip squash preparations and RAPD analysis revealed genetic similarities to ‘Frensham’ but further work to fully characterise these putative hybrids is ongoing.

II International Rose Symposium

J. Mottley, K. Yokoya, D. Matthews, J. Squirrell, J.E. Wentworth

https://doi.org/10.17660/ActaHortic.1996.424.75