[Geographical distribution and bioclimatic characteristics of the wild Gentiana rigescens resources.]

Based on the species distribution data provided by the National Specimen Information Infrastructure combined with field survey and MaxEnt model, we simulated and verified the suitable distribution area of Gentiana rigescens. Furthermore, the relationship between the geographical distribution and climatic factors of G. rigescens was analyzed. The results showed that area under curve of training set and test set were more than 0.90, indicating high prediction precision and accurate prediction results. Geographic coordinate range of G. rigescens were 22.2°─28.75° N and 98.48°─110.59° E. The suitable altitude range was from 1830 to 1959 m. The total area of suitable distribution region was 63.92×10⁴ km², including the most suitable distribution region (4.33×10⁴ km²) and middle suitable distribution region (21.42×10⁴ km²). Total area of suitable distribution region in Yunnan, Guizhou and Sichuan provinces was about 59.10×10⁴ km², which accounted for 92.46% of total suitable distribution region in China. Solar radiation (March, June and August), temperature annual range, mean temperature of warmest quarter, mean precipitation of October and November, precipitation of driest quarter were the major climatic factors influencing the geographi-cal distribution of G. rigescens. Results from partial least squares regression analysis showed that solar radiation (March, June and August), temperature annual range, mean precipitation of October and November, precipitation of driest quarter were the main restriction factors in north and east of suitable distribution region. The main restriction factors in south of suitable distribution region were solar radiation of June, mean temperature of warmest quarter, precipitation of October and November. The factors limiting distribution of G. rigescens to basin of Sichuan and Guangxi were solar radiation, temperature annual range, mean temperature of warmest quarter, annual biotempe-rature and annual potential evapotranspiration. In conclusion, suitable distribution region of G. rigescens primarily located in the Yunnan-Guizhou Plateau, where subtropical humid climate was most suitable for its growth.