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.

Novel Sources of Resistance to Phytophthora capsici on Pepper (Capsicum sp.) Landraces from Mexico

“…This wide variability enabled us to find and select plants with different resistance levels to this pathogen. These results agree with the wide variation observed in landrace and wild peppers reported in this country (Carrillo-Fasio et al, 2020;Hernández-Verdugo et al, 2006;Pacheco-Olvera et al, 2012;Retes-Manjarrez et al, 2016 regarding different morphological traits and different resistance levels to different plant pathogens.…”

“…These pepper morphotypes could potentially present different genetic background with simpler resistance mechanisms and the absence of negative linkage drags (Barchenger et al, 2018). Previous studies showed that Mexican pepper populations possess different levels of resistance to major pathogens such as virus (Retes-Manjarrez et al, 2016, and nematodes (Carrillo-Fasio et al, 2020). Based on these results, these resistant populations could serve as potential candidates to help better characterize the resistance to P. capsici, with the ultimate goal to develop resistant commercials cultivars.…”

Distribution and incidence of root-knot nematodes (Meloidogyne spp.) on pepper in Sinaloa, Mexico

“…Other explanations regarding the differences among studies of distribution and incidence of RKN from Sinaloa State could be attributed to the different agriculture systems and crops surveyed, since this study was focused on pepper under greenhouse conditions. For instance, these results agree with the prevalence and incidence reported by Carrillo-Fasio et al (2019) who did their survey with tomato cultivated under greenhouse conditions and differ from those of Carrillo-Fasio et al (2000) and Cid del Prado Vera et al (2001) who carried out their survey under open field conditions. The main differences among these studies must be due to several factors like the different crops, sites sampled, season, crop, and different agriculture systems.…”

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

“…), acerola (Malpighia emarginata), sweet potato (Ipomoea batatas), and wild watermelon (Citrullus amarus) have been reported as possible candidates with resistance to M. enterolobii (Freitas et al, 2014;Santos et al, 2021;Schwarz et al, 2021;Waldo et al, 2022). In chili pepper, mainly the species C. chinense, C. frutescens, and C. baccatum have been reported as highly resistant to M. enterolobii (Gonçalves et al, 2014;Marques et al, 2019;Pinheiro et al, 2020); however, few studies have investigated the sources of resistance in C. annuum genotypes (Marques et al, 2019;Carrillo-Fasio et al, 2020;Pinheiro et al, 2020). In this sense, Carrillo-Fasio et al (2020) found C. annuum landraces from Mexico with potential for resistance to M. enterolobii at population densities of 2000 eggs, but it is still necessary to investigate in depth the use of chili pepper landraces as a source of resistance to this nematode in order to generate information that can be incorporated into the integrated management of M. enterolobii.…”

“…In chili pepper, mainly the species C. chinense, C. frutescens, and C. baccatum have been reported as highly resistant to M. enterolobii (Gonçalves et al, 2014;Marques et al, 2019;Pinheiro et al, 2020); however, few studies have investigated the sources of resistance in C. annuum genotypes (Marques et al, 2019;Carrillo-Fasio et al, 2020;Pinheiro et al, 2020). In this sense, Carrillo-Fasio et al (2020) found C. annuum landraces from Mexico with potential for resistance to M. enterolobii at population densities of 2000 eggs, but it is still necessary to investigate in depth the use of chili pepper landraces as a source of resistance to this nematode in order to generate information that can be incorporated into the integrated management of M. enterolobii. Therefore, the aim of this study was to characterize the level of resistance in C. annuum landraces from Mexico to different population densities of M. enterolobii.…”