Species of the red algal order Acrochaetiales mostly inhabit marine environments,with only two freshwater taxa Audouinella and Ottia.A new genus and species are described for freshwater red alga Pauciramus yunnanensis...Species of the red algal order Acrochaetiales mostly inhabit marine environments,with only two freshwater taxa Audouinella and Ottia.A new genus and species are described for freshwater red alga Pauciramus yunnanensis from Ailao Mountain,Yunnan,China.It is closely related to Ottia and a new order Ottiales was proposed for these genera.Pauciramus has unique combination of morphological characteristics including the following:plants caespitose and densely pulvinate,slender uniseriate filaments with well-developed rhizoids,rarely branched,cylindrical vegetative cell with a single,ribbon-shaped and parietal chloroplast,reproduction by tetrasporangia,and dense sporangial branchlet only at the upper portion of filaments.Phylogenetic analysis of sequence data from the plastid ribulose-1,5-bisphosphate carboxylase-oxygenase large-subunit(rbc L),small subunit gene of the ribosomal cistron(SSU)and barcode region near the 5′end of the mitochondrial cytochrome oxidase subunit I(COI-5P)indicated that:the new taxon,P.yunnanensis,was in a well-supported clade with Ottia meiospora,and this clade was sister to order Palmariales and Acrochaetiales.To adhere to the principle of monophyly,a new freshwater order Ottiales including Ottia and Pauciramus is proposed.Despite the high sequence interspecific divergences and obvious morphological differences between genera Ottia and Pauciramus,seems impractical to establish a new family for a monospecific genus.Therefore,we temporarily classified Pauciramus into the family Ottiaceae,and made necessary revisions to the description to accommodate this genus.展开更多
基金Supported by the National Natural Science Foundation of China (No.41871037 to Shulian XIE and No.31800172 to Fangru NAN)the Fund for Shanxi"1331 Project"
文摘Species of the red algal order Acrochaetiales mostly inhabit marine environments,with only two freshwater taxa Audouinella and Ottia.A new genus and species are described for freshwater red alga Pauciramus yunnanensis from Ailao Mountain,Yunnan,China.It is closely related to Ottia and a new order Ottiales was proposed for these genera.Pauciramus has unique combination of morphological characteristics including the following:plants caespitose and densely pulvinate,slender uniseriate filaments with well-developed rhizoids,rarely branched,cylindrical vegetative cell with a single,ribbon-shaped and parietal chloroplast,reproduction by tetrasporangia,and dense sporangial branchlet only at the upper portion of filaments.Phylogenetic analysis of sequence data from the plastid ribulose-1,5-bisphosphate carboxylase-oxygenase large-subunit(rbc L),small subunit gene of the ribosomal cistron(SSU)and barcode region near the 5′end of the mitochondrial cytochrome oxidase subunit I(COI-5P)indicated that:the new taxon,P.yunnanensis,was in a well-supported clade with Ottia meiospora,and this clade was sister to order Palmariales and Acrochaetiales.To adhere to the principle of monophyly,a new freshwater order Ottiales including Ottia and Pauciramus is proposed.Despite the high sequence interspecific divergences and obvious morphological differences between genera Ottia and Pauciramus,seems impractical to establish a new family for a monospecific genus.Therefore,we temporarily classified Pauciramus into the family Ottiaceae,and made necessary revisions to the description to accommodate this genus.
