Nigroporusvinosus (Berk.) Murrill, first described from North America, was considered to be a common species in China. The existence of a species complex is confirmed through a phylogenetic analysis of samples examined. Based on morphological examination and molecular evidence, four new species are described as Nigroporusaustralianus, N.austroasianus, N.subvinosus and N.yunnanensis. They are characterized by pileate, effused-reflexed to resupinate, purplish, vinaceous to brown basidiomata when fresh, mostly becoming brown when dry. Nigroporusaustralianus is characterized by narrower basidiospores measuring 3.4-4.1 × 1.3-1.5 µm, thicker contextual hyphae measuring 3.2-6.4 µm in diam and a geographical distribution in Australia. Nigroporusaustroasianus is characterized by smaller pores measuring 10-13 per mm, generative hyphae dominant in the tube trama, small basidiospores measuring 3-4.1 × 1.5-2 μm and a distribution in Malaysia and tropical to subtropical regions of China. Nigroporussubvinosus is characterized by skeletal hyphae with thin to slightly thick walls, barrel- to pear-shaped basidia, and long cystidioles measuring 10-18 µm and is common in Asia. Nigroporusyunnanensis is characterized by thinner pilei measuring 2.5 mm thick at the base, bigger basidiospores measuring 4-4.5 × 1.9-2.2 μm and is found only in Yunnan. The 2-gene (ITS+nLSU) analysis of the Steccherinaceae indicated that the four new species nested in the Nigroporus clade. The 3-gene (ITS+nLSU+TEF1) analysis of the genus Nigroporus showed that N.australianus formed a monophyletic lineage, N.subvinosus was sister to N.austroasianus and N.yunnanensis, and N.austroasianus was sister to N.yunnanensis. Furthermore, N.vinosus sensu stricto is also distributed in Asia.
In this study, we isolated a virus strain (YN12031) from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic effect (CPE) 32 h post-infection. The virus particles were spherical, 70 nm in diameter, and enveloped; they also featured surface fibers. Molecular genetic analysis revealed that YN12031 was closely related to alpha viruses such as Chikungunya virus and Sindbis virus, and located in the same clade as MM2021, the prototype of Getahvirus (GETV) isolated in Malaysia in 1955. Phylogenetic analysis of the E2 and capsid genes further revealed that YN12031 was located in the same clade as the Russian isolate LEIV/16275/Mag. Analysis of the homology of nucleotides and amino acids in the coding area and E2 gene demonstrated that the YN12031 isolated from the China-Laos border (tropical region) was related closest to the LEIV/16275/Mag isolate obtained in Russia (North frigid zone area) among other isolates studied. These results suggest that GETV can adapt to different geographical environments to propagate and evolve. Thus, strengthening the detection and monitoring of GETV and its related diseases is very crucial.
Getah virus (GETV) was first isolated in Malaysia in 1955. Since then, epidemics in horses and pigs caused by GETV have resulted in huge economic losses. At present, GETV has spread across Eurasia and Southeast Asia, including mainland China, Korea, Japan, Mongolia, and Russia. Data show that the Most Recent Common Ancestor (MRCA) of GETV existed about 145years ago (95% HPD: 75-244) and gradually evolved into four distinct evolutionary populations: Groups I-IV. The MRCA of GETVs in Group III, which includes all GETVs isolated from mosquitoes, pigs, horses, and other animals since the 1960s (from latitude 19°N to 60°N), existed about 51years ago (95% HPD: 51-72). Group III is responsible for most viral epidemics among domestic animals. An analysis of the GETV E2 protein sequence and structure revealed seven common amino acid mutation sites. These sites are responsible for the structural and electrostatic differences detected between widespread Group III isolates and the prototype strain MM2021. These differences may account for the recent geographical radiation of the virus. Considering the economic significance of GETV infection in pigs and horses, we recommend the implementation of strict viral screening and monitoring programs.