Coffee leaf rust (CLR) is caused by the biotrophic fungus Hemileia vastatrix Berk. & Br., a disease of economic importance, reducing coffee yield up to 60%. Currently, CLR epidemics have negatively impacted food security. Therefore, the objective of the present research study is to show a current framework of this disease and its effects on diverse areas, as well as the biological systems used for its control, mode of action, and effectiveness. The use of essential plant oils and antagonistic microorganisms to H. vastatrix are highlighted. Terpenes, terpenoids, and aromatic compounds are the main constituents of these oils, which alter the cell wall and membrane composition and modify the basic cell functions. Beneficial microorganisms inhibit urediniospore germination and reduce disease incidence and severity. The antagonistic microorganisms and essential oils of some aromatic plants have great potential in agriculture. These biological systems may have more than one mechanism of action, which reduces the possibility of the emergence of resistant strains of H. vastatrix.

The baridinos have gained importance in agriculture; however, many of them are yet to be described, as is the case for those affecting orchids. It is for this reason that the aim of this research was to identify the insect causing the wilting of petals on orchids belonging to the Catasetum integerrimum species at a site at La Estanzuela, municipality of Emilian Zapata, and El Espinal, municipality of Naolinco, in the state of Veracruz, Mexico. Orchids of the species C. integerrimum in specimens with flowers affected were monitored, as insects cause damage to these at the time of flowering. Thus, according to the morphological characteristics of larvae and adults and of the male and female genitals observed in vegetative material, as well as larvae and adults present on the flowers, it was confirmed that the species of curculionid that attacks the orchid is Stethobaroides nudiventris Champion, 1907. This is the first report of this curculionid as the agent causing wilting on C. integerrimum petals.

Complex of borers: Ecdytolopha fabivora (Meyrick), Cydia deshaisiana (Lucas) and Cydia pomonella (L.) in crops of creole bean ( Phaseolus lunatus L.) and canavalia ( Canavalia ensiformis L.) in México

Background: The genus Xylaria comprises over 300 fungal species distributed worldwide that exhibit adaptability to various ecological roles. Consequently, their potential for the synthesis of bioactive molecules with antibacterial and antivirulence properties has been reported. Objective: To characterize the antibacterial and antivirulence properties of Xylaria sp. (OG-03) strain against phytopathogenic bacteria (Pseudomonas syringae, Pseudomonas syringae pv. tabaci, Pseudomonas putida, and Chryseobacterium sp.) and Chromobacterium violaceum 553, respectively. Methodology: A fungal strain was isolated and characterized morphologically and molecularly, and its evolutionary history was investigated through phylogenetic reconstruction. Mycelial growth was assessed in different culture media with natural substrates, and fungal extracts were obtained to evaluate minimal inhibitory (phytopathogenic bacteria) and antivirulence (biosensor strain) activities. Results: Morphological and molecular characterizations of the fungal strain suggested an indeterminate taxonomic classification at the species level within the genus Xylaria. The highest mycelial growth was observed in the REA culture medium, and the liquid rice extract promoted ectostomes proliferation. Fungal biomass extracts displayed antibacterial activity against P. syringae (MIC 7.81 µg/mL, 88% inhibition), Pseudomonas syringae pv. tabaci (MIC 1.95 µg/mL, 87% inhibition), Pseudomonas putida (MIC 1.95 µg/mL, 79.25% inhibition), and Chryseobacterium sp. (MIC 7.81 µg/mL, 85.03% inhibition), respectively. Antivirulence against C. violaceum reduced biofilm formation (125 µg/mL, 59% inhibition) and violacein production (62.5 µg/mL, 58% inhibition). Implications: Xylaria sp. exhibits antibacterial and antivirulence activity against phytopathogenic bacteria. Conclusions: The strain studied is suggested to be an undetermined taxon within the genus Xylaria. The results of biological assays indicated that the fungus possesses antibiotic properties against phytopathogenic bacteria and can inhibit virulence factors associated with quorum sensing.

Background: The root-knot nematode Meloidogyne paranaensis is one of the main phytosanitary problems in coffee crops, as it causes premature death of plants. In localities in central Veracruz, Coffea canephora plants tolerant to this nematode have been detected, which can be used as rootstocks in infested areas. Objective: To select plants that show tolerance in the field and to isolate and identify fungi associated with the rhizosphere of these coffee plants. Methodology: Plants infested with nematodes were selected and root samples were taken to quantify population density and corroborate the species. Fungi were isolated and identified from the rhizosphere soil. Five fungi were selected to observe the in vitro infection process on M. paranaensis eggs. Results: 18 plants that showed tolerance to M. paranaensis were selected. Twenty strains of fungi belonging to 7 genera and 16 species were obtained. The genera Penicillium and Fusarium were the most frequent. Clonostachys rogersoniana was the only fungus that showed parasitism against M. paranaensis eggs in vitro. Implications: The 18 selected plants show tolerance in the field, and it is necessary to conduct tests with controlled inoculations of M. paranaensis with clones and progeny. Tests on the nematophagous capacity of C. rogersoniana should continue. Conclusion: In the study area there are plants with tolerance to M. paranaensis and they can be used as rootstocks. The fungus C. rogersoniana is capable of infesting M. paranaensis eggs and is a potential biological control agent for this nematode.