Forty-seven accessions of Psidium spp. were evaluated under greenhouse conditions for resistance to M. enterolobii, as part of an effort to develop resistant rootstocks and cultivars. For each accession, five to seven plants were produced from stem cuttings or from true seeds and, at the stage of four pairs of leaves, they were inoculated with 500 nematode eggs. One hundred and thirty-five days later, the plants were removed from the pots and half of root system was processed for extraction of eggs. The plants were replanted with the remaining roots. The egg counts, obtained from three 1 mL aliquots per plant, were multiplied by two to obtain the final nematode population (Pf). The Pf values of all aliquots were submitted to ANOVA, which revealed significant differences among accessions and among plants of the same accession. The plants were classified as resistant or susceptible based on the reproduction factor (RF = Pf/500). All plants of cattley guava (P. cattleyanum) (accessions 115 and 116) were resistant (RF <1) to M. enterolobii, while other Psidium spp. presented some plants with RF below or just above 1. These plants will be propagated and reassessed for resistance to M. enterolobii.
root-knot nematode; guava decline; guava; cattley guava
