Root-knot nematodes (RKNs), Meloidogyne spp. are considered important pathogens of the coffee crop, limiting production and causing economic losses. Meloidogyne izalcoensis was recently detected in the Triângulo Mineiro region, Minas Gerais (MG) state of Brazil, parasitizing coffee plants. To investigate the distribution of this particular nematode species in this region, two small prospective surveys targeting Meloidogyne spp. on coffee plantations were carried out, employing two different techniques (esterase phenotypes (Est) and SCAR markers) in the municipalities of Araguari and Indianópolis where M. izalcoensis had been previously detected. Unfortunately, the high level of female degeneration in the second survey prevented us from identifying the species using esterase phenotypes. In both surveys, we employed the SCAR-coffee Kit, which proved to be highly effective in accurately identifying all the species of Meloidogyne found in coffee plants especially M. exigua. By using eggs and second stage juveniles (J2s) extracted from coffee roots, we obtained reliable markers for the identification of M. exigua (41.67%), M. incognita (33.33%), M. paranaensis (20.83%) and M. izalcoensis (4.17%), which can be used as unique tools in multiplex in the characterization of Meloidogyne spp. from coffee. Mixed population species were also observed in 20.83% of the samples. The use of SCAR markers proved to be the most effective tool for accurately identifying M. exigua and mixed species. These surveys confirmed that M. izalcoensis has a restricted occurrence in the region where it was initially detected.

A new root-knot nematode (RKN), Meloidogyne izalcoensis, was detected on coffee in Brazil. This species was first described on coffee from El Salvador and later detected in Asia and Africa. There are no reports on the genetic diversity of this species and resistance to M. izalcoensis has not yet been studied in coffee cultivars. All populations were identified by esterase phenotype and sequence-characterized amplified region (SCAR) species-specific markers. Based on random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers, low intraspecific variability was detected among M. izalcoensis populations from Africa, Vietnam and Brazil, but the population from El Salvador showed fewer genetic differences from the other populations. Phylogenetically, all populations of M. izalcoensis from different locations (El Salvador, Kenya, Tanzania, Vietnam and Brazil) grouped with 90% and 69% bootstrap support for COII and HSP90 regions, respectively, indicating that these markers are highly conserved for the species. In addition, both markers enabled separation of M. izalcoensis populations from other important coffee Meloidogyne species, including M. exigua, M. paranaensis, M. incognita, M. arabicida and M. lopezi. In resistance studies, most genotypes tested that had resistance to other Meloidogyne spp. (Amphillo x Catuai, Hybrid of Timor, IAPAR 59, IPR 99, IPR 100, IPR 102, IPR 103, IPR 105, IPR 106, IPR 107 and IPR 108) were found to be susceptible to M. izalcoensis, except for the rootstock cv. Apoata IAC 2258, which proved to be moderately resistant, with a genetic segregation for this character of 43.8%.

Root-knot nematodes (RKNs) are among the most economically important plant-parasitic nematodes parasitizing coffee (Coffea arabica) in the Americas, including Brazil. Meloidogyne izalcoensis is a parasite of coffee, which was first reported in El Salvador. Biochemically, the esterase phenotype is effective to differentiate M. izalcoensis from other species described from coffee. Two years ago, this nematode was detected in a sample containing coffee roots from the region of Indianópolis (Minas Gerais State, MG, Brazil). The esterase phenotype (Est I4, Rm: 0.86, 0.96, 1.24, 1.30) of this population supported the species identification of M. izalcoensis. To further confirm this identification, PCR (Polymerase Chain Reaction) using SCAR (Sequence Characterized Amplified Regions) primers amplified a specific fragment of expected size (e.g. 670 bp) typical of M. izalcoensis. Morphologically, this population was also identified as M. izalcoensis. In Minas Gerais, coffee plants were erradicated and soybean planted in the infested area. The root symptoms are completely different from other RKNs of coffee in Brazil. This is the first record of M. izalcoensis occurring on coffee in Brazil. Although the overall distribution of this species in Brazil is unknown, its occurrence on coffee would indicate a potentially important threat to the commercial cultivation of coffee, particularly in the state of Minas Gerais. This find resulted in the removal of the coffee plantation where this nematode was found.

O mofo branco causado por Sclerotinia sclerotiorum pode inviabilizar o cultivo de olerícolas em ambiente protegido. Para elaborar-se um programa de controle biológico desse patógeno, necessita-se de antagonistas adequados. Este trabalho objetivou selecionar antagonistas fúngicos eficazes no controle de S. sclerotiorum em pepineiro (Cucumis sativus) cultivado em estufa, bem como, analisar a interferência dos antagonistas no crescimento vegetal. Foram utilizados um isolado de S. sclerotiorum obtido de pepineiro e 112 isolados fúngicos de quatro gêneros: Trichoderma, Fusarium, Penicillium e Aspergillus. Em experimento in vitro, foi utilizada a técnica do papel celofane e selecionados oito isolados de Trichoderma virens, os quais promoveram maior inibição no crescimento do patógeno (94 a 100%). Dois experimentos in vivo foram desenvolvidos em estufa utilizando-se substrato autoclavado e não autoclavado, em copos plásticos, e substrato não autoclavado, em sacos plásticos; o substrato foi infestado com S. sclerotiorum e foram utilizados oito isolados de T. virens como antagonistas. Todos os isolados testados controlaram o tombamento de mudas, mas o efeito sobre o crescimento vegetal variou de acordo com os isolados e o tratamento do substrato.