Though several Diaporthe species have been reported in China, little is known about the species associated with nature reserves in Guizhou province. During a survey of fungi in six nature reserves in Guizhou province of China, thirty-one Diaporthe isolates were collected from different woody hosts. Based on morphology, culture characteristics and molecular phylogenetic analysis, these isolates were characterized and identified. Phylogenetic analysis of internal transcribed spacer region (ITS), combined with translation elongation factor 1-alpha (tef), β-tubulin (tub), calmodulin (cal) and histone H3 (his) gene regions identified five known Diaporthe species and seven distinct lineages representing novel Diaporthe species. The details of five known species: Diaporthe cercidis, D. cinnamomi, D. conica, D. nobilis and D. sackstonii are given and the seven new species D. constrictospora, D. ellipsospora, D. guttulata, D. irregularis, D. lenispora, D. minima, and D. minusculata are introduced with detailed descriptions and illustrations. This study revealed a high diversity of previously undescribed Diaporthe species associated with woody hosts in various nature reserves of Guizhou province, indicating that there is a potential of Diaporthe species remains to be discovered in this unique landform (Karst formations) in China. Interestingly, the five known Diaporthe species have been reported as pathogens of various hosts, and this could indicate that those newly introduced species in this study could be potentially pathogenic pending further studies to confirm.

https://www.mdpi.com/2309-608X/6/4/251/pdf

Unravelling Diaporthe Species Associated with Woody Hosts from Karst Formations (Guizhou) in China.

Identification and characterization of Neopestalotiopsis fungi associated with a novel leaf fall disease of rubber trees (Hevea brasiliensis) in Thailand

Research Highlights: Pestalotiopsis pini sp. nov. is an emerging pathogen on stone pine, Pinus pinea L., in Portugal. Background and Objectives: Stone pine is one of the most important forest tree species in Portugal and in the whole Mediterranean basin. Pestalotiopsis species are common endophytes, saprobes or pathogens in a variety of hosts and environments. The objective of the present study was to identify the Pestalotiopsis species associated with the symptomatic stone pine trees. Materials and Methods: Samples of stone pine trees showing shoot blight and stem necrosis were obtained from stone pine orchards and urban areas in Portugal, and the isolated Pestalotiopsis species were identified based on morphology and combined ITS, TEF and TUB DNA sequence data. Artificial inoculations on one-year-old stone pine seedlings were performed with the two species most frequently found in association with shoot blight disease. Results: Five Pestalotiopsis spp. were isolated. A taxonomic novelty, Pestalotiopsis pini is described, representing a new pathogen for stone pine. Conclusions: Pestalotiopsis species may represent a threat to the health of pine forests in the Mediterranean basin. Future research should be done in order to increase our knowledge about the potential impact of pestalotioid species in stone pine, in order to develop management strategies against these pathogens.

https://www.mdpi.com/1999-4907/11/8/805/pdf

Pestalotiopsis pini sp. nov., an Emerging Pathogen on Stone Pine (Pinus pinea L.)

Mango is one of the most popular and nutritious fruits in the world and Mexico is the world’s largest exporter. There are many diseases that directly affect fruit yield and quality. During the period 2016–2017, leaves with grey leaf spots were collected from 28 commercial mango orchards distributed in two main production areas in Sinaloa State of Mexico, and 50 Neopestalotiopsis isolates were obtained. Fungal identification of 20 representative isolates was performed using morphological characterization and phylogenetic analysis based on the internal transcribed spacer (ITS) region of ribosomal DNA, part of the translation elongation factor 1-alpha (TEF) and the β-tubulin (TUB) genes. Phylogenetic analysis indicated that the 20 isolates from this study formed four consistent groups, however, overall tree topologies do not consistently provide a stable and sufficient resolution. Therefore, even though morphological and phylogenetic separation is evident, these isolates were not assigned to any new taxa and were tentatively placed into four clades (clades A–D). Pathogenicity tests on detached mango leaves of cv. Kent showed that the 20 isolates that belong to the four Neopestalotiopsis clades from this study and induce lesions on mango leaves. This is the first report of species of Neopestalotiopsis causing mango grey leaf spot disease in Mexico.

https://www.mdpi.com/2076-0817/9/10/788/pdf

Characterization of Neopestalotiopsis Species Associated with Mango Grey Leaf Spot Disease in Sinaloa, Mexico.

AGÁPTO, João Paulo. Incidence of eucalyptus rust (Eucalyptus urograndis) in different agroforestry arrangements. 2020. 74 f. Dissertation (Master in Sustainability in Environmental Management) Federal University of São Carlos, Sorocaba campus, Sorocaba, 2020. Considered one of the main eucalyptus diseases, rust (Puccinia psidii) can cause serious damage to the crop if adequate management strategies are not implemented. In general, there is eucalyptus monoculture, with important epidemiological implications, given the fact that the spatio-temporal dynamics of the disease is affected by the distribution of the culture in the field. There is no information in the literature about the development of rust in consortium condition, such as in an agroforestry system. The aim of this study was to compare the rust progress in eucalyptus intercropped with different species, under natural infection conditions. The experiment consisted of three treatments, arranged completely randomly in space. In each treatment the eucalyptus was planted with two different species, namely: T1 Australian Cedar (Toona ciliata) + Eucalyptus (Eucalyptus urograndis) + Banana (Musa acuminata); T2 consortium Amora (Morus celtidifolia) + Eucalyptus + Pupunha (Bactris gasipaes), and T3 African Mahogany (Khaya ivorensis) + Eucalyptus + Banana. Each treatment had six repetitions, totaling 18 plots of 9 m2 (2 m x 4.5 m), arranged in alleys. Plant height and diameter, disease incidence and severity were analyzed every fifteen days. The data were collected in two different moments: pre-pruning that was in the period from 08/17/2018 to 09/01/2019 and post-pruning that occurred from 17/04/2019 to 08/13/2019. We used ANOVA followed by the Tukey test, to evaluate differences among treatments. Eucalyptus presented better development in height and diameter in the T2 treatment. The intensity of disease was also significantly lower in T2, both in incidence and severity. The results suggested that the eucalyptus planted in consortium with Amora + Eucalyptus + Pupunha provided less rust intensity.

Incidência da ferrugem do eucalipto (Eucalyptus urograndis) em diferentes arranjos agroflorestais

Brazil is the leader in the global ranking of forest productivity; however, one of the major challenges to eucalyptus production is the existence of fungal diseases. A severe epidemic caused by pestalotiopsis‐like fungi was observed in a forest nursery in Brazil, causing a huge impact on the eucalyptus micropropagation stages. The aims of the present study were to identify the causal agents associated with pestalotiopsis leaf spot and dieback in eucalyptus, assess their pathogenicity to different commercial clones, and evaluate which conditions favour conidial germination and infection by the pathogens. Multilocus phylogenetic analyses using ITS, TEF and TUB identified the isolates as members of Neopestalotiopsis and segregated them into three species. Isolates from all Neopestalotiopsis spp. caused symptoms on unwounded eucalyptus leaves and disease development was strongly dependent on long leaf wetness periods (≥72 h). All four commercial clones tested were susceptible to the pathogen. These results clearly dispute the commonly held assumption that pestalotioid fungi are weak and opportunistic pathogens. This is the first report of different phylogenetic species of Neopestalotiopsis causing dieback, leaf and stem lesions in eucalyptus cuttings and provides a basis for developing novel disease management strategies in forest nurseries.

Infection by Neopestalotiopsis spp. occurs on unwounded eucalyptus leaves and is favoured by long periods of leaf wetness

Pachira glabra (Malvaceae) occurs naturally in Brazil’s Atlantic Forest and is used to recover degraded areas of permanent preservation. Symptoms of leaf spot caused by Diaporthe spp. have been observed in P. glabra saplings in a Brazilian forest nursery. The aim of this study was to identify the fungal species employing morphological characteristics, pathogenicity tests, and DNA sequence comparisons for the internal transcribed spacer region (ITS), β-tubulin (TUB), translation elongation factor 1-α (TEF1), and calmodulin (CAL) gene regions. A novel species was identified and described, named here as Diaporthe pachirae. Furthermore, this is the first report of a species belonging to Diaporthe on P. glabra in Brazil. The current study revealed that documentation of new fungi is a relevant forerunner to any research with natural forests.

A novel species of Diaporthe causing leaf spot in Pachira glabra

Standard area diagram set to assess rust severity on eucalyptus leaves

Anthracnose stalk rot (ASR) of maize results in millions of dollars in losses annually in the United States. ASR, together with anthracnose leaf blight and anthracnose top dieback, is caused by the fungus Colletotrichum graminicola. Current ASR management recommendations emphasize host resistance and reduction of plant stressors, e.g., drought, heat, low fertility, or soil acidity. Stress reduction may be more difficult to achieve in the future due to more high-intensity production protocols and climate change. Moreover, cultural and chemical management practices may conflict with other important goals including environmental sustainability and maximization of yield potential. Thus, future ASR management may rely more heavily on host resistance, for which there are relatively few highly effective sources. The last comprehensive review of C. graminicola and maize anthracnose was written over two decades ago. The genomic age has brought important new insights into mechanisms governing the host-pathogen interaction from the application of molecular and cytological technologies. This review provides a summary of our current model of maize anthracnose etiology, including how increased knowledge of molecular and cellular events could contribute to better ASR management. Improved understanding of C. graminicola taxonomy has confirmed that the fungus is specific to Zea mays, and that it colonizes living maize tissues via a critical biotrophic phase. Successful biotrophic establishment relies on an array of secreted protein effectors and secondary metabolites produced at different stages of infection and dispersed to multiple locations. These molecules could provide therapeutic targets for the next generation of transgenic or gene-edited ASR-resistant hybrids.

Renata Belisário

Papers

Infection by Neopestalotiopsis spp. occurs on unwounded eucalyptus leaves and is favoured by long periods of leaf wetness

A novel species of Diaporthe causing leaf spot in Pachira glabra

Standard area diagram set to assess rust severity on eucalyptus leaves

Maize Anthracnose Stalk Rot in the Genomic Era.

First Report of Colletotrichum karstii Causing Anthracnose on Annona muricata in Brazil