Natural genetic variation and negative density effects in plant-nematode interactions.

is a suitable host for phytoparasitic nematodes of the genus . Successful nematode infection leads to the formation of root galls. We tested for natural genetic variation and inoculation density effects on nematode reproductive success in the interaction between and . We inoculated different Arabidopsis genotypes with two sources of nematodes at two different doses, using a mild protocol for inoculum preparation. We counted root galls and egg masses 2 months after inoculation. We obtained a high number of successful nematode infections. Infection success differed among Arabidopsis genotypes in interaction with the nematode source. Overall, infection success and reproductive success of nematodes were lower at a higher inoculum dose of nematodes. Our results indicate that natural genetic variation in both host plants and nematodes, as well as short- and long-term negative density effects, shape nematode reproductive success.