At present, the main methods of breeding Dendrobium officinale (D. officinale) include introduction and domestication, selective breeding, hybrid breeding, and mutation breeding. In the process, traditional methods of field investigation of agronomic traits are often used to select resistant varieties. Although these breeding methods are effective, they have a certain degree of subjectivity and empiricism, and the breeding cycle is long. Electrophysiological instruments were used in this experiment to test the material transport and metabolic capacity of D. officinale in a karst forest epiphytic environment and to quickly evaluate the suitability of different strains of D. officinale in a drought environment. These instruments detected the data on electrophysiological information of leaves of different strains of D. officinale under long-term drought conditions, providing immediate access to the inherent electrophysiological information of the leaves of these strains. Based on the electrophysiological parameters of D. officinale leaves as defined by the inherent electrophysiological information of plants, the water metabolism, nutrient transport, and metabolic capacity in different leaves were evaluated. The key electrophysiological indexes were verified by combining the results of chlorophyll fluorescence and chlorophyll content. The results indicate the following: (1) Parameters defined based on electrophysiological information effectively characterized the differences in intracellular water utilization, the nutrient transport status, and the metabolic capacity of different D. officinale strains. (2) The intrinsic physiological resistance, intrinsic physiological reactance, active nutrient transport capacity, and passive nutrient transport capacity were closely related to the growth status and chlorophyll function of D. officinale leaves. These electrophysiological parameters could serve as critical indicators for evaluating the drought resistance of D. officinale. (3) Under severe drought stress, strain LH1 exhibited less leaf damage, adequate water/nutrient supply, vigorous life activities, and excellent drought resistance. We found that strain LH1 demonstrates better adaptation to the arid environment of karst forest lands. The electrophysiological detection method employed in this study offers a new technique for screening wild-cultivated D. officinale resistance strains. The results indicate that the real-time online leaf electrophysiological information measured by the method in this study can characterize the energy and material metabolism of crops, greatly improving the efficiency of crop-variety selection and reducing costs. These conclusions can be used to obtain real-time information on the transmission of water and nutrients within plant cells and can provide theoretical support for studying the adaptation mechanisms of crops to adverse environments.

Dendrobium Officinale is an endangered medicinal orchid with high therapeutic value. Understanding where it can grow well and where its medicinal compounds accumulate most is important for both conservation and cultivation. In this study, we used species distribution modeling (MaxEnt) to predict suitable habitats for D. officinale in China, and combined this with field sampling and UV-Vis spectrophotometry to analyze the content of bioactive compounds in plants from four producing areas in Guizhou Province. Our results show that the potential distribution of D. officinale is primarily constrained by moisture-related variables, especially precipitation of the driest quarter, annual precipitation, and vapor pressure, as well as vegetation activity (NDVI). The total suitable area was estimated at approximately 21.4 × 10⁴ km². Phytochemical analysis of samples from four sites in Guizhou Province suggested that the accumulation of polysaccharides, alkaloids, and total phenols may respond differently to environmental factors. Alkaloids and total phenols showed strong negative correlations with precipitation-related variables (bio12, bio17), while polysaccharides exhibited positive correlations with these same variables. However, these correlations are based on a small sample (n = 4) and should be interpreted as exploratory hypotheses specific to Guizhou, rather than as established relationships. They point to the possibility that water availability during the dry season may exert opposing effects on different classes of secondary metabolites, but this conjecture requires verification with expanded sampling. Overall, this study provides a spatial framework that can inform site selection for cultivation and conservation, rather than a fully validated precision agriculture tool.

Coix lacryma-jobi L. (also known as adlay or Job's tears) is getting more attention as a functional food, but species-specific nitrogen (N) management information remains limited. Most growers currently extrapolate recommendations from other cereals. We grew C. lacryma-jobi in pots with four N rates (0, 0.5, 1.0, 2.0 g N per plant) and used ¹⁵ N-labeled KNO ₃ to track fertilizer N fate. Total biomass increased with N supply, reaching 19.74 g per plant at the highest rate—35% above the unfertilized control. Most of this extra mass accumulated in stems rather than leaves or roots. Leaf and root N concentrations rose with N supply, while stem N concentration remained stable. Only 4.8–15.1% of plant N derived from fertilizer, indicating that soil supplied 85–95% of total plant N even at the highest application rate. Nitrogen use efficiency (NUE) peaked at 13.0% at 1 g N and declined to 10.1% at 2 g N, demonstrating diminishing returns at higher N inputs. Leaf photosynthetic rate (Pn) and SPAD values increased with N supply up to 1 g N, with only modest further gains at 2 g N. Leaf nitrate concentration at 2 g N reached 1685.7 mg kg ^− 1 fresh weight. Under the conditions of this study, N application rates above approximately 1 g plant ^− 1 provide limited additional physiological or N uptake benefit and reduce fertilizer efficiency.