Response of Capsicum annuum L. var. annuum genotypes to root-knot nematode infection

Abstract

Root-knot nematodes are among the main agents that negatively affect the pepper and sweet pepper crop (Capsicum annuum L.), especially Meloidogyne incognita, M. javanica, and M. enterolobii. The objective of this study was to evaluate genotypes of C. annuum L. var. annuum in their response to infection by M. incognita race 3, M. javanica, and M. enterolobii. The experiment was conducted using a completely randomized design arranged in a 27 × 3 factorial scheme with six replicates and each plot consisted of one plant. The experiment was carried out at the UNESP-FCAV in Jaboticabal, São Paulo, Brazil. The genotypes were in plastic pots containing an autoclaved mixture of soil, sand, and bovine manure under greenhouse conditions, and they were evaluated for the reproduction index and reproduction factor at 90 d after inoculation. Thirteen genotypes were classified as resistant, based on the reproductive factor, and highly resistant, based on the reproduction index, to M. javanica, while six were resistant and highly resistant materials to M. incognita race 3. No materials resistant to M. enterolobii were identified. The genotypes CNPH 698, CNPH 701, CNPH 702, CNPH 717, and CNPH 718 were simultaneously classified as resistant to M. incognita race 3 and M. javanica based on the reproduction factor.

Bell pepper rootstocks with multiple resistance to soilborne diseases

“…The traits evaluated were the egg mass index (EMI), gall index (GI), number of eggs and second-stage juveniles per gram of root (NERG), reproduction factor (RF) (Oostenbrink, 1966), and reproduction index (RI%) (Taylor, 1967;Soares et al, 2018) 70 days after inoculation (DAI). The indexes EMI and GI were evaluated to facilitate the interpretation of the NERG, RF, and RI.…”

“…The RI% was obtained by dividing the plot's Pf by the Pf of the susceptible control (tomato cultivar Rutgers). Plants with RI > 50% were considered as susceptible, plants with RI between 26% and 50% as slightly resistant, between 11% and 25% as moderately resistant, between 1% and 10% as very resistant, plants with RI < 1% as highly resistant, and plants with RI=0% as immune (Taylor, 1967;Soares et al, 2018). Statistical analyses for the artificial inoculation experiments were carried out and means were grouped with the Scott & Knott test (p < 0.05).…”

“…Its production in greenhouses has consistently increased in Brazil and, without adequate crop rotation, the problems with soilborne pathogens have increased too. Bell peppers are especially vulnerable to the following soilborne pathogens: the bacterial species complex of Ralstonia genus, the oomycete Phytophthora capsici, and the nematodes belonging to the genus Meloidogyne (Guerrero et al, 2014;Pinheiro et al, 2014;Soares et al, 2018).…”

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

“…The search for multiple resistance to several nematodes of different genera or species in commercial rootstocks is quite difficult to achieve in practice and constitutes one of the greatest challenges for researchers (Pinheiro et al, 2014). However, different studies have been carried out focused on searching for sources of resistance using plants of wild origin, which constitute the main source of genes with resistance to pathogens such as root-knot nematodes (Soares et al, 2018).…”