Aiming to evaluate the possible mechanisms of resistance of different tomato genotypes (Lycopersicon spp.) to the whitefly Bemisia tabaci (Gennadius) biotype B, assays were performed in greenhouse and laboratory. The evaluated genotypes were 'IAC-Santa Clara' (L. esculentum), PI-127826 (L. hirsutum), PI-134417 and PI-134418 (L. hirsutum f. glabratum), LA-716 (L. pennellii), LA-371 and LA-444-1 (L. peruvianum), LA-1584 and PI-126931 (L. pimpinellifolium). Under greenhouse conditions, LA-716, PI-134417 and PI-134418 were the least attractive to whitefly. The genotype LA-716 expressed high nonpreference level; PI-134417, PI-134418, PI-127826 and PI-126931 were also resistant, but in lower levels. Regarding the whole period of development (egg-adult), the genotypes PI-127826, PI-134417, PI-134418 and LA-444-1 increased the life cycle of the insect, indicating feeding nonpreference and/or antibiosis.
Silverleaf whitefly; Lycopersicon; host plant resistance
