The oomycete P. capsici is among the major pathogens found in pepper. A desirable, sustainable and environmentally-compatible way to manage it is through genetic resistance. Huacle and Serrano pepper lines resistant to P. capsici isolate 6143 have been detected; however, it is necessary to determine whether the resistance of these lines is effective against a higher number of isolates and evaluate their resistance to other important pathogens, such as root-knot nematodes. The aim of this study was to evaluate the resistance of Huacle and Serrano pepper lines to different P. capsici isolates and root-knot nematodes (M. incognita and N. aberrans). Ten P. capsici isolates from different pepper-growing regions, and two independently-inoculated nematode populations, one of M. incognita and the other of N. aberrans, were used. Serrano pepper, lines 41-1, 41-2, 42-6 and 55-2 stood out, with a resistance response to all P. capsici isolates followed by Huacle pepper lines 33-3, 35-3 and 34-3, which were only susceptible to one isolate. Furthermore, except for lines 34-3, 35-5 and 42-2, all the others were resistant to M. incognita. Serrano pepper lines 41-1, 41-2 and 42-2 and Huacle lines 35-3 and 35-5 were resistant to N. aberrans, while lines 41-1, 41-2 and 35-3 lines were resistant to the three pathogens evaluated. Resistance previously detected in Huacle and Serrano peppers is effective for different P. capsici isolates and root-knot nematodes

The genus Serratia is widely distributed in soil, water, plants, animals, invertebrates, and humans. Some species of this genus have antifungal, antibacterial, and nematicidal activity. In this work, the nematicidal activity of the endophytic strain of Serratia sp. in chili, Capsicum annuum L., is reported, where at a bacterial concentration of 4 × 10⁹ cel/mL, the penetration of nematodes into the roots significantly decreased by 91 and 55% at 7 and 21 days after inoculation. This bacterial concentration also significantly decreased the number of galls, eggs, egg masses and reproduction factor produced by Nacobbus aberrans in Chili plants, with respect to the control where this bacterial strain was not applied. In the analysis of the genome of the strain, based on average nucleotide identity (ANI), the isolate could be affiliated to the species Serratia ureilytica. The size of the genome is 5.4 Mb, with a 59.3% content of GC. Genes related to the synthesis of chitinases, siderophores, proteases C, serralisins, hemolysin, and serrawettin W2 that have been reported for biocontrol of nematodes were identified in the genome. It is the first report of Serratia ureilytica with nematicidal activity. Based on these results of nematicidal activity, this strain can be evaluated in the field as an alternative in the biocontrol of Nacobbus aberrans in chili cultivation.

Summary: Meloidogyne enterolobii (Me) is an emerging root-knot nematode (RKN) and the most important worldwide for its high aggressiveness and increasing geographical distribution. In Mexico only in watermelon and tomato has been reported. Here we report the presence of this nematode in Jalapeño pepper collected in the state of Sinaloa. The morphological and morphometric characteristics of the second-stage juveniles and adult females were similar to those described for Me. DNA sequencing and alignment analysis (BLAST/GenBank) showed that the SCAR and rDNA IGS2 fragments had a 99 % of identity, with Me DNA sequences present in the database. The results obtained indicate that the RKN detected corresponds to M. enterolobii. To our knowledge, this is the first report of this nematode in chilli pepper in this region of Mexico, considered of major economic importance for the variety of vegetables grown and the extension of the area sown.

The main goal of this work was to evaluate the in vitro biological activity of two ferrocenyl chalcones (FcC-1 and FcC-2) against Haemonchus contortus (third-stage larvae (L₃)) and Nacobbus aberrans (second-stage juveniles (J₂)). Both compounds were synthesized and characterized by usual spectroscopic methods and their molecular structures were confirmed by single-crystal X-ray diffractometry. Nematode strains were examined in terms of percentage mortality of H. contortus (L₃) by the action of FcC-1, which showed an effectivity of 100% at a concentration of 342 μM in 24 h, with EC₅₀ = 20.33 μM and EC₉₀ = 162.76 μM, whereas FcC-2 had an effectivity of 72% at a concentration of 342 μM in 24 h, with EC₅₀ = 167.39 μM and EC₉₀ = 316.21 μM. The effect of FcC-1 against nematode phytoparasite N. aberrans showed a better percentage of 95% at a concentration of 342 μM, with EC₅₀ = 7.18 μM and EC₉₀ = 79.25 μM, whereas the effect of FcC-2 was 87% at 342 μM, with EC₅₀ = 168 μM and EC₉₀ = 319.56 μM at 36 h. After treatment, the scanning electron micrographs revealed deformities in the dorsal flank and posterior part close to the tail of H. contortus L₃. They showed moderate in vitro nematicidal activity against H. contortus L₃ and N. aberrans J₂.