RESUMEN
Colletotrichum species are well-known plant pathogens, saprobes, endophytes, human pathogens and entomopathogens. However, little is known about Colletotrichum as endophytes of plants and cultivars including Citrusgrandis cv. "Tomentosa". In the present study, 12 endophytic Colletotrichum isolates were obtained from this host in Huazhou, Guangdong Province (China) in 2019. Based on morphology and combined multigene phylogeny [nuclear ribosomal internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (gapdh), chitin synthase 1 (chs-1), histone H3 (his3) actin (act), beta-tubulin (ß-tubulin) and glutamine synthetase (gs)], six Colletotrichum species were identified, including two new species, namely Colletotrichumguangdongense and C.tomentosae. Colletotrichumasianum, C.plurivorum, C.siamense and C.tainanense are identified as being the first reports on C.grandis cv. "Tomentosa" worldwide. This study is the first comprehensive study on endophytic Colletotrichum species on C.grandis cv. "Tomentosa" in China.
RESUMEN
Diaporthe species are endophytes, pathogens, and saprobes with a wide host range worldwide. However, little is known about endophytic Diaporthe species associated with Morinda officinalis. In the present study, 48 endophytic Diaporthe isolates were obtained from cultivated M. officinalis in Deqing, Guangdong Province, China. The nuclear ribosomal internal transcribed spacer (ITS), partial sequences of translation elongation factor 1-α (tef1-α), partial calmodulin (cal), histone H3 (his), and Beta-tubulin (ß-tubulin) gene regions were sequenced and employed to construct phylogenetic trees. Based on morphology and combined multigene phylogeny, 12 Diaporthe species were identified, including five new species of Diaporthe longiconidialis, D. megabiguttulata, D. morindendophytica, D. morindae, and D. zhaoqingensis. This is the first report of Diaporthe chongqingensis, D. guangxiensis, D. heliconiae, D. siamensis, D. unshiuensis, and D. xishuangbanica on M. officinalis. This study provides the first intensive study of endophytic Diaporthe species on M. officinalis in China. These results will improve the current knowledge of Diaporthe species associated with this traditional medicinal plant. Furthermore, results from this study will help to understand the potential pathogens and biocontrol agents from M. officinalis and to develop a disease management platform.
RESUMEN
Pogostemon cablin is one of the well-known Southern Chinese medicinal plants with detoxification, anti-bacterial, anti-inflammatory, and other pharmacological functions. Identification and characterization of phytopathogens on P. cablin are of great significance for the prevention and control of diseases. From spring to summer of 2019 and 2020, a leaf spot disease on Pogostemon cablin was observed in Guangdong Province, South China. The pathogen was isolated and identified based on both morphological and DNA molecular approaches. The molecular identification was conducted using multi-gene sequence analysis of large subunit (LSU), the nuclear ribosomal internal transcribed spacer (ITS), beta-tubulin (ß-tubulin), and RNA polymerase II (rpb2) genes. The causal organism was identified as Stagonosporopsis pogostemonis, a novel fungal species. Pathogenicity of Stagonosporopsis pogostemonis on P. cablin was fulfilled via confining the Koch's postulates, causing leaf spots and stem blight disease. This is the first report of leaf spot diseases on P. cablin caused by Stagonosporopsis species worldwide.
RESUMEN
Climate change will affect numerous crops in the future; however, perennial crops, such as tea, are particularly vulnerable. Climate change will also strongly influence fungal pathogens. Here, we predict how future climatic conditions will impact tea and its associated pathogens. We collected data on the three most important fungal pathogens of tea (Colletotrichum acutatum, Co. camelliae, and Exobasidium vexans) and then modeled distributions of tea and these fungal pathogens using current and projected climates. The models show that baseline tea-growing areas will become unsuitable for Camellia sinensis var. sinensis (15 to 32% loss) and C. sinensis var. assamica (32 to 34% loss) by 2050. Although new areas will become more suitable for tea cultivation, existing and potentially new fungal pathogens will present challenges in these areas, and they are already under other land-use regimes. In addition, future climatic scenarios suitable range of fungal species and tea suitable cultivation (respectively in CSS and CSA) growing areas are Co. acutatum (44.30%; 31.05%), Co. camelliae (13.10%; 10.70%), and E. vexans (10.20%; 11.90%). Protecting global tea cultivation requires innovative approaches that consider fungal genomics as part and parcel of plant pathology.