Discovery And Molecular Identification Of A New Record Lemanea (Batrachospermales,Rhodophyta) In China

Lemanea Bory,a kind of freshwater red algae,is widely distributed throughout the world and has edible and medicinal values.This paper uses the freshwater red algae as the research material collected in Lingchuan,Guilin,Guangxi.The taxonomic status of this species and its molecular phylogenetic relationship with other Batrachospermales were studied by observing the morphological and structural characteristics and alignment analysis of rbc L gene sequence,the SSU gene sequence and the UPA gene sequence based on molecular biology classification methods.The specific research results are as follows:(1)Morphology and structure of microscopic observations: The specimens collected are belong to Lemanea,which had a similar morphological structure to Lemanea manipurensis sp.nov.The thallus is sparsely branched,the outer cortex is pseudoparenchymatous,the central axis filaments are bare lacks cortical filaments and the spermatangial patch is born on the node in a ring-shaped protrusion.The distinctive features which make it distinguish from other Lemanea are that the sporophytic branches that constitute the carposporophyte are sparse with a narrow cylindrical shape,the carpogonial branches are short in length,the carpogones formed by carpogonial filaments are sparse,the terminal cell of each carpogonial filament has a large and elongate carpospore.(2)Molecular biology analysis: Three molecular markers including the rbc L sequence,the SSU sequence,and the UPA sequence were determined,and phylogenetic studies were performed by constructing a phylogenetic tree using neighborhood-joining,maximum-likelihood,and Bayesian methods based on different gene sequences.The three phylogenetic trees based on the rbc L sequence share similar topology,and this species is clustered with L.manipurensis with a high support rate(1.00/100/100),which is consistent with morphological identification.Phylogenetic trees based on the other twomolecular markers,SSU sequence and UPA sequence,showed similar results to morphological identification.Based on the research above,the biological evolutionary status of this species of Lemanea has been confirmed,and the very species is considered to be a new record species of L.manipurensis in China.In the process,it was also found that the SSU sequence can be used for the identification of families and above,and the UPA sequence can be used with rbc L for species-level classification phylogenetic analysis.This study supplements the molecular sequence information of the rare species L.manipurensis in the Gen Bank database,which provides data support for molecular phylogenetic analysis of Lemanea in the world.It also provides theoretical basis for the application of Lemanea.