[Analysis of spatial distribution of artemisinin in Artemisia annua in China].

Geo-herbals are preferred by long-term clinical application of Chinese medicine, they are produced in a specific area and affected by the specific production and processing methods. Geo-herbals have a high reputation, compared with other regions produced by the same kind of herbs with good quality, efficacy and stable quality characteristics. Geo-herbal is a unique concept that has been formed by the history of Chinese civilization for thousands of years and the history of Chinese medicine. According to the definition of geo-herbal, it can be seen that there are some differences in the quality and efficacy of the same kind of medicinal herbs in different regions, and there is some similarity in the specific area. In this study, the spatial distribution characteristics of artemisinin in Artemisia annua were analyzed by spatial statistical analysis. ①The spatial autocorrelation of artemisinin content was analyzed by "I coefficient". The results showed that the content of artemisinin in each province was significant and positive spatial autocorrelation. The content of artemisinin in each province was not randomly distributed, but with a clear spatial aggregation characteristics. ②The spatial variability of artemisinin content was analyzed by "G statistic". The results showed that the area with high content of artemisinin was distributed in the southwest region, and the content of artemisinin was concentrated in the space, which tends to accumulate at high value. The content of artemisinin in Tianjin and Liaoning province is low, and it tends to accumulate at low value, while the content of artemisinin in other provinces is the transition zone of high and low value. ③Based on the index of artemisinin in each province, the spatial correlation of artemisinin content in each region was analyzed by "moran scatter plot". The results showed that the content of artemisinin in nine provinces such as Guangxi and Chongqing belonged to high value gathering area. ④Based on the artemisinin content and ecological environment factor of sampling point, the "geophysical detector" was used to analyze the continuous quantitative data and discontinuous qualitative data. The results showed that the sunshine, temperature and precipitation were the main factors affecting the content of artemisinin.