Screening for Resistance to Meloidogyne enterolobii in Capsicum annuum Landraces From Mexico

Abstract

Meloidogyne enterolobii has become an economically important plant parasitic nematode worldwide because of its high aggressiveness, increasing geographic distribution, wide host range, and pathogenicity in pepper (Capsicum annuum) cultivars carrying resistance genes to Meloidogyne incognita, Meloidogyne arenaria, and Meloidogyne javanica. The objectives of this study were to identify landraces of peppers resistant to M. enterolobii and analyze the relationship between resistance indicators and the phenotype parameters of plant height, stem width, leaf length, leaf width, relative chlorophyll, and number of flowers. Ninety landraces of C. annuum were collected from several states of Mexico and were inoculated with 2,000 eggs of M. enterolobii. Eleven resistant landraces were selected and confirmed with a second inoculation experiment. Seventy-five days after inoculation, in both experiments, the resistance of landraces UTC66, UTC90, UTC67, UTC88, and UTC81 to M. enterolobii was consistent. Although genotypes UTC24, UTC79, UTC65, UTC68, UTC69, and UTC25 were susceptible, these landraces had a significantly higher proportion of resistant plants, less root galling, and a lower reproductive index, in comparison with the rest of the 79 genotypes and the susceptible control, which were highly susceptible in both experiments. There was no correlation between resistant indicators and phenotypic parameters, although plant height, relative chlorophyll, and number of flowers were in general significantly affected compared with noninoculated controls, indicating that the nematodes reduce the growth and yield of peppers. Results indicate that all resistant plants from these landraces are promising sources of resistance for the development of pepper cultivars resistant to M. enterolobii.