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Members of Didymellaceae have a wide geographical distribution throughout different ecosystems, and most species are associated with fruit, leaf, stem and root diseases of land plants. However, species that occur in aquatic plants are not clearly known. During a survey of the diversity of endophytes in aquatic plants in Yunnan, Sichuan, and Guizhou provinces, we obtained 51 isolates belonging to Didymellaceae based on internal transcribed spacer region (ITS) sequences. Further, the phylogenetic positions of these isolates were determined by combined sequences composed of ITS, partial large subunit nrRNA gene (28S nrDNA; LSU), RNA polymerase II second largest subunit (rpb2) and partial beta-tubulin gene (tub2). Combining morphological characteristics and multi-locus phylogenetic analyses, two new varieties belong to Boeremia and 12 new species distributed into seven genera were recognized from 51 isolates, i.e., Cumuliphoma, Didymella, Dimorphoma, Ectophoma, Leptosphaerulina, Remotididymella, and Stagonosporopsis. Among these species, only one species of Stagonosporopsis and two species of Leptosphaerulina show teleomorphic stages on OA, but have no anamorphic state. Each new species is described in detail, and the differences between new species and their phylogenetically related species are discussed here. The high frequency of new species indicates that aquatic plants may be a special ecological niche which highly promotes species differentiation. At the same time, the frequent occurrence of new species may indicate the need for extensive investigation of fungal resources in those aquatic environments where fungal diversity may be underestimated. [ABSTRACT FROM AUTHOR]

Red palaeosol, as an important archive of ancient pedoenvironments, effectively reflects the palaeoenvironmental change and tectonic uplift history of the plateau. Four red palaeosol profiles were collected at 2200 to 2400 m elevations from the Yunnan Plateau (YP) to investigate the pedogenic features, chemical weathering process and mineral assemblages of soils. Pedological, geochemical and mineralogical techniques were used to understand the palaeopedogenic, palaeoenvironmental change and landscape evolution of the Plateau. Pedologically, the red palaeosols were characterized by the dark red color (a hue of 5YR or redder), strong acidity (pH < 5.4), and high free iron oxide (> 50 g kg − 1 ) and clay (> 50%) contents. The red palaeosols were enriched with Fe 2 O 3 , Al 2 O 3 , and TiO 2 with very low contents of CaO, MgO, Na 2 O, and K 2 O and slightly low contents of Si 2 O and MnO. Chemical weathering indices, such as CIA (CIA = [Al 2 O 3 / (Al 2 O 3 + CaO + Na 2 O + K 2 O)] × 100), Sa (Sa = SiO 2 / Al 2 O 3 ), Saf (Saf = SiO 2 / Al 2 O 3 + Fe 2 O 3 ), and A–CN–K diagram (Al 2 O 3 –CaO + Na 2 O–K 2 O), indicated that the red palaeosols had experienced strong chemical weathering processes. Scanning electron microscopy analyses revealed that quartz grains of the red palaeosols were characterized by a number of deep dissolution pits and cracks on their surfaces. The clay minerals of the red palaeosols were composed of kaolinite, gibbsite, hematite, and vermiculite in the order of abundance. Pedogenical, geochemical and clay mineralogical evidences revealed that the red palaeosols were developed by palaeopedogenic processes under tropical climatic environments. The presence of highly weathered soils at an altitude of 2200–2400 m indicated the influence of tectonic uplift on the soil vertical distribution. It is estimated that the red palaeosols had uplifted about 1600–2000 m since their initial formation. Palaeopedogenesis of red palaeosols provides new insight into the palaeoclimatic and palaeoenvironmental reconstruct and tectonic movement of YP. [ABSTRACT FROM AUTHOR]