Inheritance of resistance to root lesion nematode in red raspberry.

The inheritance of resistance to the root lesion nematode (Pratylenchus penetrans (Cobb) Filip. and Stek.] in red raspberry (Rubus idaeus L.) was studied in a four-member halfdiallel, involving two resistant genotypes and two susceptible genotypes. Estimates of general and specific combining abilities (GCA and SCA, respectively) were determined for nematode densities in roots alone and soil alone, nematode densities per plant, and plant root and foliage biomass. GCA were significant for nematodes in soil and for root and foliage biomass; SCA were significant for nematodes in the soil and for root biomass. Neither GCA nor SCA was significant for number of nematodes in the roots or per plant