An interesting group of cymbelloid diatoms was collected from lakes in Yunnan Province,China,and observations on their valve morphology made using light and scanning electron microscopy.These cymbelloid species all ha...An interesting group of cymbelloid diatoms was collected from lakes in Yunnan Province,China,and observations on their valve morphology made using light and scanning electron microscopy.These cymbelloid species all have apical pore fields,slit-like areolae,and areolar occlusions,and they all lack of stigmata.In this paper we propose the new genus Qinia gen.nov.for these taxa and describe them as new:Q.lashii sp.nov.,Q.aequalis sp.nov.,and Q.daliensis sp.nov.The genus Qinia gen.nov.has lanceolate valves asymmetrical about their apical axes,raphe located in the middle of valve,distal raphe ends bent to the dorsal margin that bisects the apical pore fields(APFs),no stigmata,areolae with slit-like external openings and projections occluding the areolar openings internally.This genus resembles the genus Cymbella in the presence of APFs,but differs from Cymbella by a lack of stigmata,and by having external distal raphe ends that bisect the apical pore fields.Like Reimeria,the external distal raphe ends bisect the lobes of the APF,but Qinia species differ from Reimeria in that they have no stigmata and the distal raphe ends are deflected dorsally,not ventrally.Comparisons were made between Qinia and other cymbelloid genera whose members possess apical pore fields.Features that distinguish each species of the new genus are also discussed.展开更多
Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of...Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of genus include:a tangentially undulated valve face;continuous cribra areolae on the valve interior consisting of pores arranged as strips;single rimoportula located inside the ring of marginal fultoportulae.Additionally,phylogenetic analysis based on nuclear small subunit(SSU)rDNA sequences and nuclear large subunit(LSU)rDNA gene placed the three strains of L.lacustris in a single,monophyletic clade at a considerable sequence distance from the other genera(Thalassiosira,Conticribra,Planktoniella,Shinodiscus,and other genera)belonging to Thalassiosirales.Despite the similarities with some species of Thalassiosira,Conticribra,and Spicaticribra,the suite of features found in Lineaperpetua differentiate it from these other genera.These molecular data and morphological characters suggest an affinity of the new genus to the Thalassiosiraceae.展开更多
基金Supported by the National Natural Science Foundation of China (Nos.31970213,31870187)the Natural Science Foundation of Heilongjiang Province for Excellent Young Scholars (No.YQ2020C032)。
文摘An interesting group of cymbelloid diatoms was collected from lakes in Yunnan Province,China,and observations on their valve morphology made using light and scanning electron microscopy.These cymbelloid species all have apical pore fields,slit-like areolae,and areolar occlusions,and they all lack of stigmata.In this paper we propose the new genus Qinia gen.nov.for these taxa and describe them as new:Q.lashii sp.nov.,Q.aequalis sp.nov.,and Q.daliensis sp.nov.The genus Qinia gen.nov.has lanceolate valves asymmetrical about their apical axes,raphe located in the middle of valve,distal raphe ends bent to the dorsal margin that bisects the apical pore fields(APFs),no stigmata,areolae with slit-like external openings and projections occluding the areolar openings internally.This genus resembles the genus Cymbella in the presence of APFs,but differs from Cymbella by a lack of stigmata,and by having external distal raphe ends that bisect the apical pore fields.Like Reimeria,the external distal raphe ends bisect the lobes of the APF,but Qinia species differ from Reimeria in that they have no stigmata and the distal raphe ends are deflected dorsally,not ventrally.Comparisons were made between Qinia and other cymbelloid genera whose members possess apical pore fields.Features that distinguish each species of the new genus are also discussed.
基金the Postdoctoral Science Foundation of China(No.2021 M 703434)the National Natural Science Foundation of China(Nos.32100165,32170205)the Natural Science Foundation of Shanghai(No.21 ZR 144730)。
文摘Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of genus include:a tangentially undulated valve face;continuous cribra areolae on the valve interior consisting of pores arranged as strips;single rimoportula located inside the ring of marginal fultoportulae.Additionally,phylogenetic analysis based on nuclear small subunit(SSU)rDNA sequences and nuclear large subunit(LSU)rDNA gene placed the three strains of L.lacustris in a single,monophyletic clade at a considerable sequence distance from the other genera(Thalassiosira,Conticribra,Planktoniella,Shinodiscus,and other genera)belonging to Thalassiosirales.Despite the similarities with some species of Thalassiosira,Conticribra,and Spicaticribra,the suite of features found in Lineaperpetua differentiate it from these other genera.These molecular data and morphological characters suggest an affinity of the new genus to the Thalassiosiraceae.
