Abstract:

Fungal, bacterial and viral diseases are serious threats to maize production. In China, maize has been planted in wide areas with different agri-ecologic types and about 30 important diseases occurred annually. Because of shorter research history and limited transmission of knowledge in maize diseases, there are some confusions in using the old pathogen names of maize diseases in China, and it affects the communication about maize diseases between researches. In this paper, six scientific names of pathogens, which causing common smut, head smut, red leaf disease, northern corn leaf spot, eyespot and black bundle disease respectively, were collated based on taxonomic history of the pathogens and advantages on modern morphological taxonomy and molecular systematics. (1) The morphological and molecular characters of causal agent of common smut showed that the agent was not closely related to species of Ustilago. The name Mycosarcoma maydis, given by Brefeld in 1912, was resurrected as the valid name for maize common smut pathogen, and Ustilago maydis, a widely used name, was the synonym now. (2) Based on host selection, sporocarp morphology, host disease characteristics and result in multiple gene analyses within Sporisorium, Sphacelotheca and other related genera, Sporisorium reilianum, re-established by Langdon & Fullerton in 1978, was described as the correct name of pathogen causing maize head smut. The name, Sphacelotheca reiliana, was as one of synonyms. Because of host specificity between maize and sorghum, the maize pathogen also named as Sporisorium reilianum f. sp. zeae. (3) The virus Barley yellow dwarf virus (BYDV) is generally considered to be causal agent of maize red leaf disease. Recently, some virus strains infected maize were sequenced, and results showed clearly that Wheat yellow dwarf virus-GPV and Maize yellow dwarf virus-RMV all belong to Polerovirus genus, are pathogens causing the disease in China. (4) In spite of similar in morphology, but it is proved that genus Kabatiella is completely different from the genus Aureobasidium by multigene phylogenetic analyses. The correct name of pathogen causing maize northern corn leaf spot is Kabatiella zeae, and Aureobasidium zeae is its synonym. (5) Helmintosporium-like fungi have undergone several changes in genera. By detailed analysis on morphology, DNA sequence data, mode of life and novel metabolite production showed that Bipolaris zeicola, causing eyespot on maize, is a valid and conserved anamorph name. The name of Bipolaris was protected over Cochliobolus and approved by the Nomenclature Committee for Fungi. (6) The name Cephalosporium acremonium was confusingly used to different fungi long-time and it has lost the strict concept of criterion species. Acremonium, including more than 150 species, is also highly polyphyletic taxon with several teleomorph genera. Molecular biological characters showed the heterogeneity of the genus Acremonium. By combining molecular characteristics with morphology, old Acremonium species were reclassified into some genera, and the name Sarocladium strictum was given to the pathogen of maize black bundle disease with the synonyms Cephalosporium acremonium and Acremonium strictum.

Key words: maize, pathogen, scientific name, collation