Rheum nanum, a perennial herb, is a famous traditional Chinese medicinal plant that has great value in modern medicine. In order to determine the potential distribution of R. nanum in Asia, we specifically developed the potential distribution maps for three periods (current, 2050s: 2041–2060, and 2070s: 2061–2080) using MaxEnt and ArcGIS, and these were based on the current and future climate data under two climate scenarios (RCP2.6 and RCP6.0). To predict the potential impacts of global warming, we measured the area of suitable habitats, habitat suitability changes, and habitat core changes. We found that bio16 (i.e., the precipitation of the wettest quarter) and bio1 (i.e., the annual mean temperature) were the most important climate factors that influenced the distribution of R. nanum. The areas of high suitable habitats (HH) and middle suitable habitats (MH) in the current period were 156,284.7 ± 0.99 km² and 361,875.0 ± 3.61 km², respectively. The areas of HH and MH in 2070RCP6.0 were 27,309.0 ± 0.35 km² and 123,750 ± 2.36 km², respectively. The ranges of 82.0–90.3° E, 43.8–46.5° N were the mostly degraded areas of the 2050s and 2070s, and RCP6.0 had a larger decrease in habitable area than that found in RCP2.6. All the HH cores shifted south, and the shift distance of HH in 2070RCP6.0 was 115.65 km. This study provides a feasible approach for efficiently utilizing low-number occurrences, and presents an important attempt at predicting the potential distribution of species based on a small sample size. This may improve our understanding of the impacts of global warming on plant distribution and could be useful for relevant agricultural decision-making.

Selenium (Se) deficiency in humans could be improved by biofortification of food with selenium, 1-Methylcyclopropene (1-MCP) treatment is beneficial for the non-sulfur storage of fresh fruit. This study investigated fruit quality of table grape (Hutai No.8) with foliar Se fertilizer at maturity, and fruit quality changes of table grape during shelf life stages that caused by postharvest 1-MCP treatment in 2016 and 2017. The results showed that foliar Se fertilizer application significantly increased Se content in grape berries at maturity, and the raised rate were 43.09% and 33.24% compared to that of control in 2016 and 2017 respectively, meanwhile it increased the nutritional components in grape berries, including soluble proteins, soluble sugars, Vitamin C, total soluble solids, proanthocyanidin content and so on, and decreased the titratable acidity content. During shelf life stages, 1-MCP application decreased the decay number of grapes, and SE + 1-MCP treatment had the most excellent fruit quality among all treatments in two consecutive vintages. In conclusion, Se fertilizer application could increase Se content in grape berries, also improved the fruit nutritional and health care values at maturity. 1-MCP application could delay the process of ripening and senescence for Se-enriched grape and maintaining the postharvest quality of table grape during shelf life stages, it allows us to market the fruit at a more advanced ripening stage without quality loss.

The Loess Plateau, known for its fragile ecosystems, is one of the traditional apple-producing regions in China. Although some management measures are needed to enhance sustainable agriculture in response to the rising pressure of climate change, the geographic distribution of apple trees considering multiple variables has not been considered. In this study, we used three software (the maximum entropy model, IDRISI, and ArcGIS) to simulate the potential distribution of suitable habitats and range shifts of apple trees in the near present and near future (i.e., the 2030s and the 2050s) under two climate scenarios (the Shared Socioeconomic Pathways (SSP)1-26 and SSP5-85), while taking a variety of environmental factors into account (e.g., temperature, precipitation, and terrain). After optimization, the class unsuitable habitat (CUH) changed the potential distribution pattern of apple trees on the Loess Plateau. Currently, the areas of lowly suitable habitat (LSH), moderately suitable habitat (MSH), highly suitable habitat (HSH), and CUH were 7.66 × 10⁴, 2.80 × 10⁴, 0.23 × 10⁴, and 18.05 × 10⁴ km², respectively. Compared to the centroid estimated under the climate of 1970–2000, the suitability range of apple trees was displaced to the northwest in both the 2030s and the 2050s in SSP5-85 (i.e., 63.88~81.30 km), causing a larger displacement in distance than SSP1-26 (i.e., 40.05~50.32 km). This study demonstrates the possible changes in the spatial distribution of apple trees on the Loess Plateau in the near future and may provide a strong basis for future policy making.