Weathering process of rocks in Antarctica can be accelerated by the colonization of lichens, which dominate surface vegetation and endolithic communities respectively in the maritime Antarctic and in Antarctic cold de...Weathering process of rocks in Antarctica can be accelerated by the colonization of lichens, which dominate surface vegetation and endolithic communities respectively in the maritime Antarctic and in Antarctic cold deserts. The effects of lichens on their substrate rocks can be attributed to both physical and chemical causes. As the result of the weathering induced by lichens, the surface corrosion and exfoliation of colonized rocks occur. The mobilization of iron in the rock forming minerals and the precipitation of poorly ordered iron oxides are investigated. Furthermore, the neoformation of crystalline metal oxalates and secondary clay minerals are identified in the colonized rocks. Due to unique climatic conditions, the biotic weathering process of rocks in Antarctica somewhat differs from that of other regions of the world.展开更多
Mycelium-like structures found under ESEM within radial sections of fragmental dinosaur eggshells would be the endolithic fungi coexistent with dinosaur eggs in the upper part of the Late Cretaceous Hugang Formation f...Mycelium-like structures found under ESEM within radial sections of fragmental dinosaur eggshells would be the endolithic fungi coexistent with dinosaur eggs in the upper part of the Late Cretaceous Hugang Formation from the Wenjiaping section of Wenxian, Danjiangkou, northwestern Hubei, Central China. The endolithic fungi selectively occurred in the bad biomineral zone within the columnar layer of the eggshells, where the crowded endolithic fungi penetrated the columnar layer at near-vertical or near-horizontal angles. The endolithic fungi are needle-like, ribbon-like and silk-like, and 5–18 μm long, 0.3–0.5 μm wide at their base, with pointed tip, and are unbranched. The hyphae are mainly composed of oxygen, carbon and calcium, and are with minor sodium, potassium, chlorine and sulfur. The endolithic fungi and host have the same characters in lithification, fracture and main chemical composition. We suggested that the episode endolithic fungi invading dinosaur eggs may have taken place in the interval between after formation of dinosaur eggshells and before their petrification and that dinosaur eggs invaded by endolithic fungi would not be normally incubated or would only be incubated into venerable and pathologic baby dinosaurs to be easily to aborted and contributed to the mass extinction of the dinosaurs at the end of Cretaceous.展开更多
【目的】了解新疆特殊生境不同类型岩石内生细菌的组成及多样性。【方法】采用末端限制性片段长度多态性技术(Terminal Restriction Fragment Length Polymorphism,T-RFLP),分析新疆乌苏花岗岩(1号样)、一号冰川和木垒变质岩(2,3号样)...【目的】了解新疆特殊生境不同类型岩石内生细菌的组成及多样性。【方法】采用末端限制性片段长度多态性技术(Terminal Restriction Fragment Length Polymorphism,T-RFLP),分析新疆乌苏花岗岩(1号样)、一号冰川和木垒变质岩(2,3号样)、裕民和托克逊岩石漆(4,5号样)内生细菌群落。【结果】样品间多样性指数变化不大;聚类分析表明岩石类型相同,其相似性较高,2号样和3号样聚为一支并与1号样再聚为一支,4号样与5号样聚为一支;各样品共有种群为厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes),1号样存在酸杆菌门(Acidobacteria),2号样存在浮霉菌门(Planctomycetes);除5号样优势类群为放线菌门(29.3%),其它4个样品均为变形菌门,只是所占比例略有不同。【结论】生境不同的同类型岩石的内生细菌群落组成存在差异,各类岩石中可能存在大量未知细菌新种。展开更多
The fungal genus Collemopsidium comprises species that develop so-called borderline lichen symbioses with algae or cyanobacteria.Together with morphologically similar pyrenocarpous fungi it has been assigned to the fa...The fungal genus Collemopsidium comprises species that develop so-called borderline lichen symbioses with algae or cyanobacteria.Together with morphologically similar pyrenocarpous fungi it has been assigned to the family Xanthopyreniaceae.The adscription of this family to higher taxonomic ranks remain uncertain.Using sequence data of five nuclear genomic regions(nuLSU,nuSSU,tef1-α,rpb1 and rpb2)and onemitochondrial locus(mtSSU)we found that the studied representatives of this family are placed in the Dothideomyceta,yet relationships with the classes Dothideomycetes and Arthoniomycetes remain uncertain.We describe the new order Collemopsidiales to accommodate the genus Collemopsidium(paraphyletic as currently understood)and the lichenicolous genus Zwackhiomyces.Using five fungal fossils as calibrations points,we infer an age of c.230 Mya for the crown of Collemopsidiales.Based on two molecular markers,we also provide insight into the global diversity of marine species of the genus Collemopsidium.According to the species delimitation algorithm GMYC,c.26 putative species exist,far more than the six species recognized hitherto.We have confirmed this result by comparing the two alternative species models by means of Bayes factors,using path sampling and stepping-stone sampling algorithms to estimate the marginal likelihood of each model.Finally,our observations suggest rock-boring ability evolved in parallel in the different lineages within this group of fungi.展开更多
文摘Weathering process of rocks in Antarctica can be accelerated by the colonization of lichens, which dominate surface vegetation and endolithic communities respectively in the maritime Antarctic and in Antarctic cold deserts. The effects of lichens on their substrate rocks can be attributed to both physical and chemical causes. As the result of the weathering induced by lichens, the surface corrosion and exfoliation of colonized rocks occur. The mobilization of iron in the rock forming minerals and the precipitation of poorly ordered iron oxides are investigated. Furthermore, the neoformation of crystalline metal oxalates and secondary clay minerals are identified in the colonized rocks. Due to unique climatic conditions, the biotic weathering process of rocks in Antarctica somewhat differs from that of other regions of the world.
基金the Special Project of Basic Research of China (Grant No. 2005CCA05000)the National Natural Science Foundation of China (Grant Nos. 40472020 and 40621002)+1 种基金the 111 Project (Grant No. B08030)the SINOPEC Project (Grant No. G0800-06-ZS-319)
文摘Mycelium-like structures found under ESEM within radial sections of fragmental dinosaur eggshells would be the endolithic fungi coexistent with dinosaur eggs in the upper part of the Late Cretaceous Hugang Formation from the Wenjiaping section of Wenxian, Danjiangkou, northwestern Hubei, Central China. The endolithic fungi selectively occurred in the bad biomineral zone within the columnar layer of the eggshells, where the crowded endolithic fungi penetrated the columnar layer at near-vertical or near-horizontal angles. The endolithic fungi are needle-like, ribbon-like and silk-like, and 5–18 μm long, 0.3–0.5 μm wide at their base, with pointed tip, and are unbranched. The hyphae are mainly composed of oxygen, carbon and calcium, and are with minor sodium, potassium, chlorine and sulfur. The endolithic fungi and host have the same characters in lithification, fracture and main chemical composition. We suggested that the episode endolithic fungi invading dinosaur eggs may have taken place in the interval between after formation of dinosaur eggshells and before their petrification and that dinosaur eggs invaded by endolithic fungi would not be normally incubated or would only be incubated into venerable and pathologic baby dinosaurs to be easily to aborted and contributed to the mass extinction of the dinosaurs at the end of Cretaceous.
文摘【目的】了解新疆特殊生境不同类型岩石内生细菌的组成及多样性。【方法】采用末端限制性片段长度多态性技术(Terminal Restriction Fragment Length Polymorphism,T-RFLP),分析新疆乌苏花岗岩(1号样)、一号冰川和木垒变质岩(2,3号样)、裕民和托克逊岩石漆(4,5号样)内生细菌群落。【结果】样品间多样性指数变化不大;聚类分析表明岩石类型相同,其相似性较高,2号样和3号样聚为一支并与1号样再聚为一支,4号样与5号样聚为一支;各样品共有种群为厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes),1号样存在酸杆菌门(Acidobacteria),2号样存在浮霉菌门(Planctomycetes);除5号样优势类群为放线菌门(29.3%),其它4个样品均为变形菌门,只是所占比例略有不同。【结论】生境不同的同类型岩石的内生细菌群落组成存在差异,各类岩石中可能存在大量未知细菌新种。
基金SPO,IGB and AdR were supported by grant CTM2012-38222-C02-02IGB was supported by grant FPU AP2012-3556SPO is currently supported by the grant RYC-2014-16784,all from the Spanish Ministry of Economy and Competitiveness.
文摘The fungal genus Collemopsidium comprises species that develop so-called borderline lichen symbioses with algae or cyanobacteria.Together with morphologically similar pyrenocarpous fungi it has been assigned to the family Xanthopyreniaceae.The adscription of this family to higher taxonomic ranks remain uncertain.Using sequence data of five nuclear genomic regions(nuLSU,nuSSU,tef1-α,rpb1 and rpb2)and onemitochondrial locus(mtSSU)we found that the studied representatives of this family are placed in the Dothideomyceta,yet relationships with the classes Dothideomycetes and Arthoniomycetes remain uncertain.We describe the new order Collemopsidiales to accommodate the genus Collemopsidium(paraphyletic as currently understood)and the lichenicolous genus Zwackhiomyces.Using five fungal fossils as calibrations points,we infer an age of c.230 Mya for the crown of Collemopsidiales.Based on two molecular markers,we also provide insight into the global diversity of marine species of the genus Collemopsidium.According to the species delimitation algorithm GMYC,c.26 putative species exist,far more than the six species recognized hitherto.We have confirmed this result by comparing the two alternative species models by means of Bayes factors,using path sampling and stepping-stone sampling algorithms to estimate the marginal likelihood of each model.Finally,our observations suggest rock-boring ability evolved in parallel in the different lineages within this group of fungi.
