Approximately 1 000 plants of 116 individuals belonging to the CMB9B family were multiplied by means of embryo rescue and in vitro propagation. For the phenotypic assessment under high whitefly pressure, 30-d-old plants were distributed in the A. socialis colony, following a randomized complete block design; that is, 5 plants per genotype in 3 replications with susceptible genotype CMC40 as the control. The plants were evaluated individually, recording the number of eggs per genotype on the first two leaves over a period of 48 h. In order to identify the segregating populations, we developed the following oviposition preference scale: 0-20 eggs (1=resistant); 21- 80 eggs (2, 3, 4=intermediate); 81-99 eggs (5=susceptible) and 100 eggs (6=susceptible).