BREEDING FOR FIRE BLIGHT RESISTANCE WITHIN A MULTIPLE RESISTANCE BREEDING PROGRAMME IN APPLES

The aim of the apple breeding programme is the combination of different sources of resistance and good fruit quality in new cultivars.
The best of these have resistance to scab, mildew, fire blight, bacterial canker, red spider mite, winterfrost and good fruit quality.
Various donors like Malus robusta, Malus prunifolia, Malus floribunda as well as a few Pillnitz Pi- and Re-cultivars® are used for fire blight resistance.
Donors of alleles for fire blight have been found in progenies involving M. x floribunda and some cultivars.
Progenies of ‘Clivia’, ‘Golden Delicious’, ‘Alkmene’ and clone ‘Pi-A-44, 14’ produce a good percentage of seedlings with a remarkable level of fire blight resistance.
Fire blight resistant Pillnitz Re-cultivars® are ‘Remo’, ‘Rewena’, ‘Rene’, ‘Reanda’ and ‘Realka’. Triple resistant cultivars with resistance to scab, mildew and fire blight are ‘Remo’, ‘Rewena’, and ‘Reanda’. They possess a high level of fire blight resistance in the growing shoots and in the flowers.
In many cases flowers and shoot resistance (‘Rewena’, ‘Reanda’), susceptibility (‘James Grieve’, ‘Idared’) are correlated, but in some cultivars this correlation is broken (‘Yellowspur’). Parents with triple resistance transmit a high degree of resistance to their progenies.
The best population, ‘Pi-AS-44, 14’ x ‘Rewena’ on average produced one triple-resistant plant for every seven seedlings tested.

VII International Workshop on Fire Blight

C. Fischer, K. Richter

https://doi.org/10.17660/ActaHortic.1996.411.77