The taxonomy of the genus Colletotrichum has undergone tremendous changes over the last decade, with over 200 species being currently recognised and species complexes being informally used to cluster those species. Many of these species are important plant pathogens, some rather polyphagous and others host-specific, but several occur seldomly and some may in fact be ecologically endangered. Based mainly on literature from the past decade, in this work we review the occurrence, geographic distribution and host spectrum of currently recognised Colletotrichum species under phylogenetic, pathological/agronomic and ecological perspectives, providing a list arranged by Colletotrichum species and species complexes. A total of 257 species are listed and grouped into 15 species complexes. In this work we have recorded 1353 unique host species-Colletotrichum species association records from 720 hosts, with the Fabaceae as the family with higher number of hosts (52 host species) but with the Rosaceae as the family with the highest number of host species-Colletotrichum species association records (118 association records). According to occurrence data, 88 species are common in nature, 128 were considered as data deficient and 41 are threatened, some of which are likely extinct from nature and preserved only in culture collections. Several species are relevant plant pathogens, in some cases geographically confined and thus of potential quarantine relevance. Based on the major changes that occurred on Colletotrichum taxonomy over the last decade, this work provides a comprehensive overview of occurrence data of Colletotrichum species, compiling host range and geographical distribution, with relevance for plant pathology and conservation mycology. The current taxonomic framework in Colletotrichum is revealing numerous species but poses challenges to the employment of standard criteria for the evaluation of biological conservation of these fungi. We advocate that conservation mycology and taxonomy should find common routes simultaneously enabling the correct delimitation of species of Colletotrichum and the implementation of feasible criteria for the evaluation of conservation. The employment of new technologies, such whole genome sequencing (WGS), will help and support the description of new species and to gain a better understanding of the genetic bases of speciation processes.

Colletotrichum species and complexes: geographic distribution, host range and conservation status

In tropical fruit crops, anthracnose is mainly caused by species belonging to the fungal genus, Colletotrichum. These phytopathogens can infect several parts of the fruit crops; however, infection during postharvest or ripening stages is responsible for major economic losses. Due to the formation of black to dark brown sunken lesions on the fruit surface, anthracnose reduces fruit quality and marketability. Among the most common tropical fruit crops susceptible to anthracnose are mango, papaya, banana, avocado, guava, and dragon fruit; these are economically relevant products in many developing countries. It is important to document that the newly recorded Colletotrichum spp. associated with fruit anthracnose can infect multiple hosts, but some species may be host-specific. By using multiple markers, many phylogenetic species of Colletotrichum have been reported as anthracnose-causing pathogens. Taking into account that disease management strategies strongly rely on adequate knowledge of the causative agents, updated information on Colletotrichum species and the hazard posed by the most recently identified species in tropical fruit plantations and harvested fruits becomes vital. Besides, the newly recorded species may be important for biosecurity and should be listed as quarantine pathogens, considering that tropical fruits are traded worldwide.

Diversity of Colletotrichum Species Associated with Anthracnose Disease in Tropical Fruit Crops—A Review

Phenylphenalenones, polycyclic aromatic natural products from some monocotyledonous plants, are known as phytoalexins in banana (Musa spp.). In this study, (1) H nuclear magnetic resonance (NMR)-based metabolomics along with liquid chromatography and mass spectrometry were used to explore the chemical responses of the susceptible 'Williams' and the resistant 'Khai Thong Ruang' Musa varieties to the ascomycete fungus Mycosphaerella fijiensis, the agent of the black leaf Sigatoka disease. Principal component analysis discriminated strongly between infected and non-infected plant tissue, mainly because of specialized metabolism induced in response to the fungus. Phenylphenalenones are among the major induced compounds, and the resistance level of the plants was correlated with the progress of the disease. However, a virulent strain of M. fijiensis was able to overcome plant resistance by converting phenylphenalenones to sulfate conjugates. Here, we report the first metabolic detoxification of fungitoxic phenylphenalenones to evade the chemical defence of Musa plants.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/pce.12630

Phenylphenalenones protect banana plants from infection by Mycosphaerella fijiensis and are deactivated by metabolic conversion

Subcellular damages of Colletotrichum asianum and inhibition of mango anthracnose by dielectric barrier discharge plasma.

Resumen es: El objetivo de este trabajo fue elaborar mediante un procedimiento computarizado una escala logaritmica diagramatica de severidad para el patosistema Ann...

Escala logarítmica Diagramática de Severidad de la Mancha Negra (Colletotrichum gloeosporioides Penz.) en Chirimoyo (Annona cherimola Mill.)

Mango anthracnose, caused by Colletotrichum spp., is the most significant disease of mango (Mangifera indica L.) in almost all production areas around the world. In Mexico, mango anthracnose has only been attributed to C. asianum and C. gloeosporioides. The aims of this study were to identify the Colletotrichum species associated with mango anthracnose symptoms in Mexico by phylogenetic inference using the ApMat marker, to determine the distribution of these species, and to test their pathogenicity and virulence on mango fruits. Surveys were carried out from 2010 to 2012 in 59 commercial orchards in the major mango growing states of Mexico, and a total of 118 isolates were obtained from leaves, twigs, and fruits with typical anthracnose symptoms. All isolates were tentatively identified in the C. gloeosporioides species complex based on morphological and cultural characteristics. The Bayesian inference phylogenetic tree generated with Apn2/MAT intergenic spacer sequences of 59 isolates (one per orchard) revealed that C. alienum, C. asianum, C. fructicola, C. siamense, and C. tropicale were associated with symptoms of mango anthracnose. In this study, C. alienum, C. fructicola, C. siamense, and C. tropicale are reported for the first time in association with mango tissues in Mexico. This study represents the first report of C. alienum causing mango anthracnose worldwide. The distribution of Colletotrichum species varied among the mango growing states from Mexico. Chiapas was the only state in which all five species were found. Pathogenicity tests on mango fruit cultivar Manila showed that all Colletotrichum species from this study could induce anthracnose lesions. However, differences in virulence were evident among species. C. siamense and C. asianum were the most virulent, whereas C. alienum and C. fructicola were considered the least virulent species.

Distribution and Pathogenicity of Colletotrichum Species Associated With Mango Anthracnose in Mexico

The objective of this study was to document new host plants and the geographical distributions of Melanagromyza floris Spencer, M. tomaterae Steyskal, M. viridis (Frost) and Ophiomyia lantanae (Froggatt). The study was carried out from August 2007 to August 2008. Puparia of these flies were collected on Tithonia sp. in Tonatico (state of Mexico); Physalis nicandroides Schltd in Atotonilco el Grande (state of Hidalgo); Tagetes erecta L. and Lantana camara L. in Huautla (state of Hidalgo) and Lantana camara L. in San Joaquin, state of Queretaro. Both flies and host plants were identified. T. erecta is a new host record for M. floris whereas P. nicandroides is a new host record for M. tomaterae. The flies M. floris and M. tomaterae are the first reports for these species in the state of Hidalgo. M. viridis is recorded from the southern part of the state of Mexico. Finally, O. lantanae is registered in two states: Hidalgo and Queretaro.

https://azm.ojs.inecol.mx/index.php/azm/article/download/680/963

Nuevos registros y extensiones de distribución de mamíferos para Guanajuato, México

La necrosis floral, pudricion y caida de frutos juveniles del papayo (Carica papaya L.) son enfermedades con incidencia alta y reducen la productividad de huertos comerciales en Huamuxtitlan, Guerrero, Mexico. El objetivo del presente estudio fue determinar la etiologia y epidemiologia de estas enfermedades. De flores y frutos necroticos se aislaron Cladosporium sp. y Fusarium spp., y en proporcion menor Alternaria sp. y Colletotrichum sp. Las especies Fusarium equiseti, F. chlamydosporum, Cladosporium cladosporioides y Alternaria alternata provocaron necrosis y caida floral 8 d despues de la inoculacion (ddi) y necrosis, pudricion y caida de frutos juveniles 15 ddi. Colletotrichum gloeosporioides provoco lesiones necroticas en 30 % de las flores inoculadas y no causo sintomas en frutos. La dinamica poblacional de esporas de Alternaria spp. y Fusarium spp. en el aire se estudio en una plantacion de papayo cv. Maradol de marzo del 2007 a marzo del 2008; las esporas de ambos hongos se encontraron de mayo a octubre, aunque el numero mayor se capturo en mayo y septiembre. Las esporas de Fusarium spp. fueron mas abundantes en horario nocturno (20:00 a 04:00 h) y las de Alternaria spp. entre las 12:00 y 14:00 h. Fusarium equiseti, F. chlamydosporum, Cladosporium cladosporioides y Alternaria alternata son agentes patogenos de la necrosis de flores y pudricion y caida de frutos juveniles del papayo en Huamuxtitlan, Guerrero, Mexico. Los propagulos de Alternaria spp. y Fusarium spp. estan dispersos en el ambiente de la zona de estudio de mayo a octubre

/pdf/etiologia-y-epidemiologia-de-la-necrosis-de-flores-y-frutos-4pxes9zir8.pdf

Etiología y epidemiología de la necrosis de flores y frutos juveniles del papayo (Carica papaya L.) en Guerrero, México

El control de Sigatoka negra (Mycosphaerella fijiensis Morelet) del banano (Musa acuminata Colla AAA) y platano (Musa balbisiana Colla AAB) requiere de numerosas aplicaciones de fungicidas, principalmente de los grupos triazoles que inducen alta presion de seleccion en poblaciones del patogeno. El objetivo del presente estudio fue determinar la respuesta de cepas de M. fijiensis aisladas de plantaciones de banano de Tabasco y Chiapas, Mexico, al propiconazol y tridemorf. Los bioensayos se realizaron en medio de cultivo Papa Dextrosa Agar (PDA®) adicionados con diferentes concentraciones del fungicida. Los medios se inocularon con 100 µL de una suspension conidial y fragmentos miceliares del hongo, y se incubaron en oscuridad a 26 °C por 7 d. La concentracion efectiva 50 (CE50) y 95 % (CE95) para cada aislamiento se estimo mediante analisis Probit del porcentaje de inhibicion del crecimiento relativo del patogeno. Los valores CE50 en propiconazol variaron de 0.0001 a 0.95 mg L–1; y los de CE95 de 0.006 a 12.51 mg L–1. La proporcion de resistencia en el nivel CE95 fue superior a 2085x, para el aislamiento MF–RmC2 de la finca Remedios en Teapa, Tabasco. Los valores para CE50 en tridemorf variaron de 0.00001 a 0.002 mg L–1 y los de CE95 de 0.03 a 0.85 mg L–1. La proporcion de resistencia a nivel CE95 entre el aislamiento sensible de referencia y el menos susceptible (MF–RcC5 de la finca el Recreo, Tabasco) fue superior a 28.3x. La correlacion positiva entre el numero de aplicaciones y los valores de CE50 y de CE95 son indicativos de que la presion de seleccion ejercida en esta plantacion genero resistencia al propiconazol

Resistencia a fungicidas en poblaciones de Mycosphaerella fijiensis del sureste mexicano

The epidemics caused by papaya ring spot virus (PRSV-P) (Carica papaya L.) have been delayed by an integral management system (MIP), although the individual effectiveness of some components has not been measured. The establishment of corn (Zea mays L.) barriers was evaluated in the control of PRSV-P in Veracruz, Mexico. The MIP included the protection of the nursery with polypropylene mesh, 2743 plants ha -1 , eradication of diseased plants, mineral fertilization and weed control. Treatments were: integral management with corn barriers (MIP), integral management without barriers (MIZ) and regional management (MR, 1600 plants ha -1 , using insecticides, without barriers and elimination of diseased plants). The logistic model adequately explained the incidence in MIP, MIZ and MR, and severity (R 2 =0.92 to 0.97) in MIZ; the

/pdf/barreras-de-maiz-en-una-estrategia-de-manejo-integral-para-2lxts0vdhq.pdf

Barreras de maíz en una estrategia de manejo integral para controlar epidemias del virus mancha anular del papayo (prsv-p) corn barriers in an integrated management strategy to control epidemics of papaya ring spot virus (prsv-p)

Cristian Nava-Díaz

Papers

Distribution and Pathogenicity of Colletotrichum Species Associated With Mango Anthracnose in Mexico

Nuevos registros y extensiones de distribución de mamíferos para Guanajuato, México

Etiología y epidemiología de la necrosis de flores y frutos juveniles del papayo (Carica papaya L.) en Guerrero, México

Resistencia a fungicidas en poblaciones de Mycosphaerella fijiensis del sureste mexicano

Barreras de maíz en una estrategia de manejo integral para controlar epidemias del virus mancha anular del papayo (prsv-p) corn barriers in an integrated management strategy to control epidemics of papaya ring spot virus (prsv-p)