In January 2017, symptoms of a leaf-spot disease were observed on Viscum coloratum plants in Yichun,China. The infected leaves were chlorotic, while sunken lesions formed on diseased branches, which were initially lig...In January 2017, symptoms of a leaf-spot disease were observed on Viscum coloratum plants in Yichun,China. The infected leaves were chlorotic, while sunken lesions formed on diseased branches, which were initially light brown and later turned dark brown. Moreover, diseased branches and leaves formed semi-buried, small, and spherical pycnidia. In total, 20 leaves and 19 branches diseased samples from Yichun, China were collected and examined. The fungus was isolated and identified using Koch’s postulates, morphological characteristics and DNA sequence data. The data presented herein confirmed that the pathogen responsible for the disease was Sphaeropsis visci. To the best of our knowledge, this is the first report of it in China.展开更多
In plant pathology,the correct naming of a species is essential for determining the causal agents of disease.Species names not only serve the general purpose of concise communication,but also are critical for effectiv...In plant pathology,the correct naming of a species is essential for determining the causal agents of disease.Species names not only serve the general purpose of concise communication,but also are critical for effective plant quarantine,prevent-ing the introduction of new pathogens into a territory.Many phytopathogenic genera have multiple species and,in several genera,disagreements between the multiple prevailing species concept definitions result in numerous cryptic species.Some of these species were previously called by various names;forma speciales(specialised forms),subspecies,or pathotypes.However,based on new molecular evidence they are being assigned into new species.The frequent name changes and lack of consistent criteria to delineate cryptic species,species,subspecies,forms,and races create increasing confusion,often making communication among biologists arduous.Furthermore,such ambiguous information can convey misleading evo-lutionary concepts and species boundaries.The aim of this paper is to review these concepts,clarify their use,and evaluate them by referring to existing examples.We specifically address the question,“Do plant pathogens require a different ranking system?”We conclude that it is necessary to identify phytopathogens to species level based on data from multiple approaches.Furthermore,this identification must go beyond species level to clearly classify hitherto known subspecies,forms and races.In addition,when naming phytopathogenic genera,plant pathologists should provide more information about geographic locations and host ranges as well as host specificities for individual species,cryptic species,forms or races.When describing a new phytopathogen,we suggest that authors provide at least three representative strains together with pathogenicity test results.If Koch’s postulates cannot be fulfilled,it is necessary to provide complementary data such as associated disease severity on the host plant.Moreover,more sequenced collections of species causing diseases should be published in order to stabilise the boundaries of cryptic species,species,subspecies,forms,and races.展开更多
基金supported by the forestry public welfare industry research special-study group on cultivation and utilization of medicinal fungi and astragalus in Daxing’anling(201004079)
文摘In January 2017, symptoms of a leaf-spot disease were observed on Viscum coloratum plants in Yichun,China. The infected leaves were chlorotic, while sunken lesions formed on diseased branches, which were initially light brown and later turned dark brown. Moreover, diseased branches and leaves formed semi-buried, small, and spherical pycnidia. In total, 20 leaves and 19 branches diseased samples from Yichun, China were collected and examined. The fungus was isolated and identified using Koch’s postulates, morphological characteristics and DNA sequence data. The data presented herein confirmed that the pathogen responsible for the disease was Sphaeropsis visci. To the best of our knowledge, this is the first report of it in China.
基金We would like to thank the Thailand Research Fund,Grant RDG6130001 entitled“Impact of climate change on fungal diversity and biogeography in the Greater Mekong Subregion”.Kevin D Hyde thanks Chiang Mai University for the award of a Visiting Professor.Ishara S Manawasinghe thank Prof Marco Thines for guiding the development of this paper by providing valuable ideas and comments.Alan JL Phillips acknowledges the support from UIDB/04046/2020 and UIDP/04046/2020 Centre grants from FCT,Portugal(to BioISI).
文摘In plant pathology,the correct naming of a species is essential for determining the causal agents of disease.Species names not only serve the general purpose of concise communication,but also are critical for effective plant quarantine,prevent-ing the introduction of new pathogens into a territory.Many phytopathogenic genera have multiple species and,in several genera,disagreements between the multiple prevailing species concept definitions result in numerous cryptic species.Some of these species were previously called by various names;forma speciales(specialised forms),subspecies,or pathotypes.However,based on new molecular evidence they are being assigned into new species.The frequent name changes and lack of consistent criteria to delineate cryptic species,species,subspecies,forms,and races create increasing confusion,often making communication among biologists arduous.Furthermore,such ambiguous information can convey misleading evo-lutionary concepts and species boundaries.The aim of this paper is to review these concepts,clarify their use,and evaluate them by referring to existing examples.We specifically address the question,“Do plant pathogens require a different ranking system?”We conclude that it is necessary to identify phytopathogens to species level based on data from multiple approaches.Furthermore,this identification must go beyond species level to clearly classify hitherto known subspecies,forms and races.In addition,when naming phytopathogenic genera,plant pathologists should provide more information about geographic locations and host ranges as well as host specificities for individual species,cryptic species,forms or races.When describing a new phytopathogen,we suggest that authors provide at least three representative strains together with pathogenicity test results.If Koch’s postulates cannot be fulfilled,it is necessary to provide complementary data such as associated disease severity on the host plant.Moreover,more sequenced collections of species causing diseases should be published in order to stabilise the boundaries of cryptic species,species,subspecies,forms,and races.
