Characterization of resistance responses to Meloidogyne enterolobii in Capsicum annuum landraces from Mexico

Rita J. Salazar-Mesta1, José A. Carrillo-Fasio1, Jesús E. Retes-Manjarrez2, Raymundo S. García-Estrada1, Josefina León-Félix1, and Juan M. Tovar-Pedraza1*
Meloidogyne enterolobii is currently the most damaging nematode of the genus Meloidogyne due to its aggressiveness and ability to overcome existing sources of resistance; therefore, the search for genotypes with resistance in crops of high economic importance such as chili pepper (Capsicum annuum L. var. annuum) is one of the greatest challenges facing agricultural researchers. The aim of this study was to determine the level of resistance in C. annuum landraces from Mexico to different population densities of M. enterolobii. Five C. annuum landraces (UTC24, UTC25, UTC66, UTC67, and UTC90) and the commercial cv. Revelation were used. The experiment was conducted twice under greenhouse conditions with a randomized block design with four replicates per genotype and cultivar. Inoculation was performed on 21-d-old seedlings with inoculum doses of 0, 4500, 9000, and 13500 eggs plant-1. The gall index, reproduction factor, and reproduction index were evaluated at 42 and 63 d after inoculation. Genotypes UTC66, UTC67, and UTC90 showed a higher level of resistance with a damage percentage lower than 50% compared to ‘Revelation’ (susceptible). Genotype UTC90 showed the lowest reproduction factor and index, so it was considered a highly resistant genotype to an inoculum dose of 4500 M. enterolobii eggs with a damage percentage of less than 10%, while, at a dose of 13 500 eggs, its resistance level was intermediate. The results of this study contribute to the search for sources of resistance to M. enterolobii in chili pepper landraces.
Keywords: Gall index, landraces, plant parasitic nematode, reproduction factor, reproduction index, resistance.
1Centro de Investigación en Alimentación y Desarrollo, Coordinación Regional Culiacán, 80110, Culiacán, México.
2Fyffes, Finca El Oasis La Fragua, 19016, Zacapa, Guatemala.
*Corresponding author (juan.tovar@ciad.mx).