RECENT DEVELOPMENTS IN BREEDING FOR FRUIT ROT RESISTANCE IN RED RASPBERRY

Variations in postharvest resistance to 3 fruit rot causal organisms, Botrytis cinerea Pers. ex Fr., Rhizopus spp. and Penicillium spp. have been observed among red raspberry (Rubus idaeus L.) cultivars and selections (clones) in the British Columbia (BC) breeding program.

Among the clones which showed resistance to all 3 causal organisms were BC 64-6-142, Matsqui and Meeker, all derivatives of Cuthbert which is a source of genes for resistance to B. cinerea, Rhizopus spp. and possibly to Penicillium spp. as well. Black raspberry (R. occidentalis L.) derivatives, from the Scottish Horticultural Research Institute breeding program, were resistant to B. cinere a but not to Rhizopus spp.

The need for diversification of the genetic base of fruit rot resistance is stressed because of the possibilities of strain variations in B. cinerea, species and strain variations in Rhizopus and Penicillium and also the existence of other rot causal organisms.