Molecular Identification of Salvia miltiorrhiza Bge. and Its Adulterants Based on ITS2 Sequences

[ Objectives] The study was conducted to investigate the molecular identification of Salvia miltiorrhiza Bge. and its adulterants by DNA barcoding andspecific primer PCR. [ Methods] With ITS2 sequenceas DNA barcode, the materials were amplified by PCR and sequenced, and the NJ phylogenetic tree was constructed. The secondary structure of ITS2 was predicted by database and its website established by Koetschan et al. , and the self-designed primers were used to carry out specific primer PCR identification. [Results] ITS2 sequence length was around 470 bp. The results of cluster analysis showed that S. miltiorrhiza Bge. and its adulterants were clustered on different branches and showed monophyly. The comparison of secondary structure showed that S. miltiorrhiza Bge. had little differences from S. przewalskii, while there were significant differences from A. lappa in the number, size and location of stem-loop and the rotation angle of the spiral arm from the central ring. The specific primers could distinguish the S. miltiorrhiza Bge. and its counterfeits by PCR technique. [Conclusions] DNA barcoding and specific primer PCR are effective in distinguishing S. miltiorrhiza Bge. and its adulterants, and it has an important application foreground in the identification of Chinese herbal medicines.

Research on the Relationship between Chinese Express Delivery Industry and Economic Development Based on PVAR Model

Based on the panel vector autoregressive model (PVAR) and the panel data of China’s 31 provinces from 2010 to 2019, this paper conducts a quantitative analysis on the dynamic balance relationship between China’s express business volume and economic development status in recent 10 years. The results show that: Firstly, there is a long-term equilibrium relationship between the development level of express industry and the economic development level;Secondly, the relationship between them presents regional heterogeneity (that is, the East, Centre and the West show different characteristics);Finally, in the short term, the development of express delivery industry and economic development can well drive each other, but in the long term, this trend is not obvious, and the economic impact of express delivery industry has a certain lag.

Research on the Influence of Population Structure on Economic Growth: Based on the Provincial Panel Data Model

In recent years, the international environment and conditions of China’s economic development have undergone profound and complex changes, but in the middle and long term, China’s economy has been maintaining a stable medium-high speed development. It is remarkable that population changes bring about changes in economic development;especially the aging of the population has a particularly significant impact on economic growth. Therefore, based on the inter-provincial panel data of 31 provinces and municipalities from 2011 to 2019, this paper mainly studies the impact of population change on economic growth by establishing a solid fixed effect model. The results show that there is a long-term equilibrium relationship between population structure and economic growth, and population structure has a significant positive impact on economic development. In addition, there are regional differences in the positive and significant relationship between the two.