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Copyright of Canadian Journal of Plant Pathology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Castor bean (Ricinus communis) is a crop of great economic importance in Brazil. It is used for producing oil used in the manufacture of cosmetics and biodiesel. The genus Phytophthora contains pathogens with a wide range of host plants, including ornamentals, fruit and vegetable crops. Among the symptoms induced by Phytophthora species are collar and root rot. This study aimed to identify Phytophthora species causing collar and root rot in castor bean seedlings in the Federal District and test their pathogenicity. Samples of symptomatic plants were collected in four satellite cities in Distrito Federal, Brazil. Fourteen isolates were obtained, and they were initially identified through the morphology of reproductive structures. The isolates were subjected to molecular characterization using phylogeny of the sequences from the ITS region and the Cytochrome Oxidase II gene. Ten isolates of the pathogen were tested for pathogenicity on seedlings of two castor bean accessions and species known to be hosts of P. nicotianae. The isolates were identified as P. nicotianae (12 isolates) and P. palmivora (two isolates). In the pathogenicity test, all isolates were capable of causing disease in castor beans. The isolates of P. nicotianae and P. palmivora varied in pathogenicity to other plant species. This is the first report of P. nicotianae causing collar and root rot in castor bean in the Central‐West Region of Brazil. It is also the first report of P. palmivora causing diseases in castor beans in South America. [ABSTRACT FROM AUTHOR]

Pythium tracheiphilum is a narrow host range oomycete first described infecting lettuce in Italy. Subsequently, the pathogen was reported in many other countries. From 2015 to 2019, Pythium isolates were recovered from lettuce plants with symptoms of leaf rot, wilting and vascular necrosis, collected from commercial fields in different rural localities of Brasilia‐DF, Brazil. The isolates were identified as P. tracheiphilum based on morphological and molecular genetic analysis. Pathogenicity tests conducted with four P. tracheiphilum isolates confirmed that the isolates were pathogenic to detached leaves of a loose‐hearted lettuce cultivar. This is the first report of P. tracheiphilum infecting lettuces in Brazil. [ABSTRACT FROM AUTHOR]

Aim An extensive survey was done to clarify the prevalent Stemphylium species on Solanaceae plants across Brazil, and their host ranges. Methods and Results Eighty nine (89) Stemphylium isolates were obtained from naturally infected tomatoes as well as S. paniculatum , potato, eggplant, scarlet eggplant (Solanum aethiopicum var. gilo), Physalis angulata , and Capsicum species. Phylogenetic analyses encompassing the ITS-5.8S rDNA and glyceraldehyde-3-phosphate dehydrogenase genomic regions placed the isolates into two distinct groupings with either Stemphylium lycopersici or S. solani. Isolates of S. lycopersici (n  = 81) were obtained infecting tomato, potato, eggplant, S. paniculatum , and P. angulata. Isolates of S. solani (n  = 8) were detected in natural association with scarlet eggplant and tomato. Two isolates of S. lycopersici displayed a wide experimental host range in greenhouse bioassays, infecting accessions of 12 out of 18 species. Ocimum basilicum (Lamiaceae) was the only experimental host outside the Solanaceae family. [ABSTRACT FROM AUTHOR]

Wilting and crown‐rot symptoms were observed in sweet pepper (Capsicum annuum) plants in field surveys carried out in 2021 across major vegetable‐producing areas of three municipalities of Guatemala. Phytophthora capsici (Peronosporales, Peronosporaceae) isolates were identified in association with these symptoms based upon morphological and phylogenetic analyses using nucleotide sequence information of the Cox2 mitochondrial DNA (mtDNA) region. Biological tests confirmed P. capsici mating type A1 isolates as the causal agents of the disease. Symptoms similar to those observed in the field were obtained after controlled inoculation of C. annuum 'Tico' seedlings. Solanum habrochaites 'LA 404' and C. annuum 'Criollo de Morelos' displayed strong resistance reaction against all Guatemalan isolates. Even though P. capsici is a cosmopolitan pathogen, this is the first molecular confirmation of this pathogen infecting C. annuum in Guatemala. [ABSTRACT FROM AUTHOR]

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel powdery mildew disease was observed on chickpea (Cicer arietinum) in Brazil. The morphological features of fungal colonies and conidia were in agreement with those typical for the genus Leveillula. The total DNA of three field‐collected samples were used as template in PCR assays with the pair of primer PMITS1 and PMITS2, targeting the internal transcribed space (ITS) region of Erysiphales isolates. Amplicons were Sanger sequenced and their BLAST analysis revealed 100% identity with a large number of L. taurica (lato sensu, Clade 1) isolates from GenBank. Phylogenetic analysis confirmed the pathogen identification. Equivalent symptoms were observed on chickpea seedlings after controlled inoculation, fulfilling the Koch's postulates. Leveillula taurica (lato sensu, Clade 1) isolates have been reported infecting Fabaceae hosts worldwide, including chickpeas in North America, Africa and Asia. However, this is the first record of L. taurica infecting this crop in Brazil and South America. [ABSTRACT FROM AUTHOR]