Geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms in China

China covers a vast territory harbouring a large number of aquatic plants. Although there are many studies on the β-diversity of total, herbaceous or woody plants in China and elsewhere, few studies have focused on aquatic plants. Here, we analyse a comprehensive data set of 889 aquatic angiosperm species in China, and explore the geographic patterns and climatic correlates of total taxonomic and phylogenetic β-diversity as well as their turnover and nestedness components. Our results show that geographic patterns of taxonomic and phylogenetic β-diversity are highly congruent for aquatic angiosperms, and taxonomic β-diversity is consistently higher than phylogenetic β-diversity. The ratio between the nestedness component and total β-diversity is high in northwestern China and low in southeastern China. The geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms in China are obviously affected by geographic and climatic distances, respectively. In conclusion, the geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms are consistent across China. Climatic and geographic distances jointly affect the geographic patterns of β-diversity of aquatic angiosperms. Overall, our work provides insight into understanding the large-scale patterns of aquatic angiosperm β-diversity, and is a critical addition to previous studies on the macroecological patterns of terrestrial organisms.

Use of fluorescent substrate 4-MUP in the detection of biotin-labeled DNA probes

To improve the sensitivity of detecting biotin-labeled DNA Probes, a new fluorescent substrate of alkaline phosphatase, 4-methylum belliferylphosphate (4-mup) was studied instead of conventional BCIP-NBT. The result of dot-blot hybridization demonstrates that this new substrate can be used for the colorimetric detection of biotin-labeled probes after hybridization to immobilized nucleic acids. The sensitivity is about one order of magnitude higher than that of BCIP-NBT system, and the time required for color development is very short, only about five min. It is suggested that the Bio-SA-Bio-AP-4-MUP colorimetric detection system can be widely used in gene diagnosis.