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Colletotrichum truncatum (syn. C. capsici) has been identified as the causal agent of anthracnose on various hosts, predominantly pepper (Capsicum spp.) plants. The aim of this study was to determine whether C. truncatum isolates infecting papaya, pepper and physic nut in southeastern Mexico are morphologically, genetically and pathogenically different, in order to improve disease management strategies. A total of 113 C. truncatum isolates collected from five producer states were subjected to phenotypic characterization and divided into six different morphological groups. These morphological traits and the location of the isolates were used to select a subset of 20 isolates for further studies. Differences in the pathogenicity of the isolates were tested with a cross‐inoculation assay using pepper, papaya and physic nut. The pathogenicity tests revealed that all isolates could infect the three hosts and produce typical anthracnose symptoms, indicating a lack of host specificity for this species and therefore its pathogenic potential on other plants. Phylogenetic analysis using internal transcribed spacer (ITS) and glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) sequences of the C. truncatum isolates from this study and reference strains was performed, grouping the isolates into a monophyletic clade. This study reports for the first time the characterization of C. truncatum causing anthracnose disease on three different hosts in Mexico. [ABSTRACT FROM AUTHOR]

Papaya meleira virus ( PMeV), the causal agent of papaya sticky disease, was first reported in Brazil and more recently in Mexico. Yield losses in papaya ( Carica papaya) orchards related to this virus can be considerable over relatively short time spans. To date, very little is known regarding the transmission mechanisms of PMeV, which has made it difficult to effectively control the virus and to prevent dissemination. A few published reports have claimed that PMeV is not seed-transmissible. However, in this study, evidence is presented for seed transmission of PMeV in papaya cultivar Maradol. Three seed materials (whole dry seed, seed coat and embryo-endosperm) from Maradol were analysed using reverse transcription-polymerase chain reaction. A seed transmission rate of c. 81% was observed, suggesting that this mechanism is an important route of virus dissemination. For the first time, this study shows that PMeV is seedborne and can be transmitted to the next generation through contaminated papaya seeds. [ABSTRACT FROM AUTHOR]

The article presents the first report of a 16SrIII, X-disease phytoplasma affecting tomato plants in Mexico. As reported, ymptoms of leaf yellowing and curling, little leaf, and severe stunting have been observed recently in tomato fields in the Yucatan Peninsula, with an incidence of about 50%. Leaf samples were collected by the researchers and the total DNA was extracted and used as template in a nested PCR assay for the amplification of the phytoplasma 16SrRNA gene.