Resistance screening against the South American tomato pinworm (Tuta absoluta) in tomato by means of a simple bioessay

Se describe un bioensayo en invernáculo para evaluar poblaciones segregantes de tomate para la resistencia a la polilla del tomate (Tuta absoluta Meyrick = Scrobipalpuloides absoluta Meyrick). Se evaluaron dos cultivares de Lycopersicon esculentum y tres accesiones silvestres del género Lycopersicon. Se infestaron hojas jóvenes completamente expandidas de plantas adultas cultivadas en macetas en invernáculo, con hojas de tomate que llevaban larvas neonatas de polilla. El grado de infestación se evaluó a los 7, 14 y 21 días después de iniciado el bioensayo. No se encontraron diferencias significativas entre plantas dentro de genotipos. Se encontraron diferencias altamente significativas entre genotipos a los 21 días. La heredabilidad en sentido amplio del grado de infestación a los 21 días fue de 0,95 lo que demuestra su alta repetibilidad. Se concluye que el bioensayo es simple, altamente repetible y permite discriminar entre plantas resistentes y susceptibles en grandes poblaciones segregantes en el invernáculo y en el campo.A greenhouse bioessay is described for screening resistance against the South American tomato pinworm (Tuta absoluta Meyrick = Scrobipalpuloides absoluta Meyrick) in large tomato populations. Two L. esculentum cultivars and three wild Lycopersicon accessions were evaluated. Young fully expanded leaves of adult plants grown in pots were infested using young tomato leaves carrying neonate larvae. The infestation rate was evaluated 7, 14 and 21 days after the infestation. No differences were found between plants within genotypes. Highly significant differences between genotypes were found twenty one days after the infestation date. The broadsense heritability of the infestation rate at twenty one days was 0.95, indicating the high reproducibility of the bioessay. The current results show that the bioessay is simple, highly reproducible and it allows the discrimination between resistant and susceptible plants in large segregating populations, both in the greenhouse and in the field.Facultad de Ciencias Agrarias y Forestale