ABSTRACT
Acanthus ilicifolius is an excellent mangrove plant. In this study, the complete chloroplast genome of A. ilicifolius, a salt tolerant plant of Acanthaceae, was generated. The length of chloroplast genome is 150,758 bp, in which the large-single copy region (LSC) is 82,963 bp, the small-single copy (SSC) region is 17,191 bp, and a pair of inverted repeat (IRa and IRb) regions is 25,302 bp. The chloroplast genome contains 128 genes, including 84 protein-coding genes, eight rRNA genes, and 36 tRNAs genes, with a total GC content of 38%. Phylogenetic analysis showed that A. ilicifolius was closely related to A. ebracteatus, both species belonged to Acanthus genus.
ABSTRACT
Two cruises were carried out in the Yangtze River Estuary and its adjacent sea (29 degrees 30' - 32 degrees 00'N, west of 123 degrees E) in July (summer) and November (autumn), 2005. A total of 345 phytoplankton species, including 43 species causing red tide, were identified. Skeletonema costatum was the dominant species. The average cell abundance was lower in July (5.48 x 10(4) cells L(-1)) than in November (2.70 x 10(5) cells L-(-1)), but the average chlorophyll a concentration was higher in July (2.34 mg x m(-3)) than in November (1.32 mg x m(-3)). The average diversity index (H) was higher in July (1.51) than in November (0.86), as was average evenness (J) (0.59 and 0.34, respectively). Spatial distribution of phytoplankton featured distinct regionality, and the seasonal variation was controlled by factors such as water source, monsoon, nutrient, suspended matter, etc., and the diurnal variation mainly correlated with tide and stratification. At the same time, an evaluation of long-term monitoring data (1996 - 2005) showed that phytoplankton community structure had been changed. Long-term unbalance of N/P ratio caused dinoflagellates to increasingly dominate the phytoplankton population, and led to an increasing frequency of red tide caused by dinoflagellates. Controlling nutrient ratios is more important than just controlling terrigenous contamination input in improving sea area environmental status.
