Chromoblastomycosis is a chronic, cutaneous and subcutaneous infection caused by members of the order Chaetothyriales and commonly found in China. Among the etiologic agents, members of the genus Cladophialophora are predominant in northern China. Alternatively, Fonsecaea spp. are particularly common in southern China. However, the identification of Fonsecaea isolates recovered in China is difficult due to the fact that different species lack distinctive morphological characters. Therefore, the identification of 24 Fonsecaea isolates from symptomatic patients were re-evaluated by using morphology, ITS rDNA sequence diversity and partly through the use of randomly amplified polymorphic DNA (RAPD) typing. Twenty strains, including a morphological mutant were found to be Fonsecaea monophora, while four strains corresponded to F. pedrosoi. We have demonstrated that Fonsecaea monophora is the predominant etiologic agent of chromoblastomycosis in southern China and populations showed marked geographic structuring.

We report the first case of chromoblastomycosis caused by a meristematic mutant of Fonsecaea monophora in an 81-year-old Cantonese male. The patient had a seven-month history of a red plaque with thick yellow crust and purulent exudates on the back of his right hand. Microscopic examination of direct smears revealed brown sclerotic cells and black colonies were recovered in culture from samples of the purulent exudantes. The microscopic appearance of this isolate was quite different from that of other Fonsecaea species, exhibiting mere meristematic growth. The rDNA ITS sequence data confirmed that this isolate was a mutant of Fonsecaea monophora. The patient showed good response to treatment with itraconazole and complete healing was achieved without relapse after long-term follow-up.

Background Allotetraploid oilseed rape (Brassica napus L.) is an important worldwide oil-producing crop. The origin of rapeseed is still undetermined due to the lack of wild resources. Despite certain genetic architecture and phylogenetic studies have been done focus on large group of Brassica nuclear genomes, the organelle genomes information under global pattern is largely unknown, which provide unique material for phylogenetic studies of B. napus. Here, based on de novo assemblies of 1,579 B. napus accessions collected globally, we constructed the chloroplast and mitochondrial pan-genomes of B. napus, and investigated the genetic diversity, phylogenetic relationships of B. napus, B. rapa and B. oleracea. Results Based on mitotype-specific markers and mitotype-variant ORFs, four main cytoplasmic haplotypes were identified in our groups corresponding the nap, pol, ole, and cam mitotypes, among which the structure of chloroplast genomes was more conserved without any rearrangement than mitochondrial genomes. A total of 2,092 variants were detected in chloroplast genomes, whereas only 326 in mitochondrial genomes, indicating that chloroplast genomes exhibited a higher level of single-base polymorphism than mitochondrial genomes. Based on whole-genome variants diversity analysis, eleven genetic difference regions among different cytoplasmic haplotypes were identified on chloroplast genomes. The phylogenetic tree incorporating accessions of the B. rapa, B. oleracea, natural and synthetic populations of B. napus revealed multiple origins of B. napus cytoplasm. The cam-type and pol-type were both derived from B. rapa, while the ole-type was originated from B. oleracea. Notably, the nap-type cytoplasm was identified in both the B. rapa population and the synthetic B. napus, suggesting that B. rapa might be the maternal ancestor of nap-type B. napus. Conclusions The phylogenetic results provide novel insights into the organelle genomic evolution of Brassica species. The natural rapeseeds contained at least four cytoplastic haplotypes, of which the predominant nap-type might be originated from B. rapa. Besides, the organelle pan-genomes and the overall variation data offered useful resources for analysis of cytoplasmic inheritance related agronomical important traits of rapeseed, which can substantially facilitate the cultivation and improvement of rapeseed varieties.