Physiological and DNA fingerprinting of the bacterial community of Meloidogyne fallax egg masses

Bacterial communities associated with the plant-parasitic nematode Meloidogyne fallax egg masses were compared with those present in the rhizoplane. Two agricultural soils with different nematode population dynamics were used in a glasshouse study, with either potato or tomato as host plant for the nematode. DNA fingerprints and bacterial community level physiological profiles (CLPP) were studied using PCR-DGGE of 16S rRNA genes and Biolog Eco MicroPlates. CLPP and DNA fingerprinting both showed differences between egg mass and rhizoplane bacterial communities. PCR-DGGE showed some bands specific to the egg mass samples. These bands were present in egg masses from both soils. This study shows that egg masses of M. fallax have a distinct bacterial community from that of the adjacent rhizoplane. Soil and host plant factors interactively influence the bacterial egg mass community. Differences in nematode population dynamics between the sample sites cannot be clearly related to the observed differences in the egg mass microbial communities.