The inheritance of resistance to the root lesion nematode [Pratylenchu
s penetrans (Cobb) Filip. and Stek.] in red raspberry (Rubus idaeus L.
) was studied in a four-member half diallel, involving two resistant g
enotypes and two susceptible genotypes. Estimates of general and speci
fic combining abilities (GCA and SCA, respectively) were determined fo
r nematode densities in roots alone and soil alone, nematode densities
per plant, and plant root and foliage biomass. GCA were significant f
or nematodes in soil and for root and foliage biomass; SCA were signif
icant 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.