Algal Flora Of Yuncheng Salt Lake Water System And Phylogenetic And Classification Of Dunaliella Sp.YC01

Yuncheng salt lake water system is composed of Yuncheng salt lake and surrounding reservoirs, ponds, ditches, swamps and streams. According to water salinity, Yuncheng salt lake water system can be divided into:fresh water bodies (with salt content at 0.01-0.5%), mesohalinous water bodies (with salt content at 0.5-30%), euhalinous water bodies (with salt content at 30-40%) and polyhalinous water bodies (with salt content at 40-347%). In this study, we had collected water samples from Yuncheng salt lake water system in November 2011, June and November 2012, and June 2013. We did a comprehensive research on algae of Yuncheng Salt Lake water system, the main results are as follows:(1) With the changes of salinity, the numbers and kinds of algae species were very different in Yuncheng Salt Lake water system. Lots of algae species were observed in fresh water and euhalinous water, with a complex community compostion. Middle numbers algae species were observed in euhalinous water, with abundant of associated species. Only a few algae species existed in polyhalinous water.(2) Alga in Yuncheng salt lake was mainly contains of Cyanophyta, Chlorophyta and Diatoms. The numbers of algal species is gradually reduced with increase of salinity. With a survey of salinity adaptation of 39-kinds salt-tolerant alga, we found that some alga were able to survie in a wide range of salinity, and some alga survived in a certain rangle of salinity.(3) A Dunaliella strain (with the name Dunaliella sp. YC01) was isolated from Yuncheng salt lake, and morphology and molecular methods were used to identify this micro-algae. The cells contained one cup-shaped chloroplast occupying about half of the cell interior, and a single pyrenoid surrounded by several starch bodies. Flagella were a bit longer than the length of the cell.18S rDNA, rbcL, psaB and ITS of Dunaliella sp. YC01 was amplified and sequenced, and 1,721-,731-,1,197-and 727-bp amplicons were obtained. Phylogenetic trees were constructed with the four gene sequences. Phylogenetic analysis of 18S rDNA gene indicated that Dunaliella sp. YC01 is closely related to Dunaliella salina (AF506698) and Dunaliella salina strain UTEX 1644 (DQ009765). Phylogenetic analysis of rbcL gene indicated that Dunaliella sp YC01 is closely related to Dunaliella peircei UTEX 2192 (DQ313196) and Dunaliella salina strain 9802 (EF695405). Phylogenetic analysis of psaB and ITS, Dunaliella sp. YC01 is closely related to Dunaliella tertiolecta (JQ039051) and Dunaliella salina strain 9802 (EF695405), respectively. In summary, Dunaliella sp. YC01 is closely related to Dunaliella salina, Dunaliella peircei and Dunaliella tertiolecta, and more likely closer to Dunaliella salina. Combined morphological characteristic with phylogenetic analysis, Dunaliella sp. YC01 should be a strain of Dunaliella salina.