Erythropalum scandens Bl. is a woody vegetable with high nitrogen demand that inhabits southern China. Ammonium and nitrate are the two main forms of inorganic nitrogen that plants directly absorb. A pot experiment was performed to determine the growth, physiological responses, and preferences of 12-month-old E. scandens seedlings for ammonium and nitrate. Aboveground and underground growth indexes, biomass, physiological and biochemical indexes (chlorophyll [Chl], soluble sugar, soluble protein and free proline contents), and substrate pH and nitrogen contents were determined under different nitrate and ammonium ratios (0 NO₃^-: 100 NH₄⁺, 25 NO₃^-: 75 NH₄⁺, 50 NO₃^-: 50 NH₄⁺, 75 NO₃^-: 25 NH₄⁺, and 100 NO₃^-: 0 NH₄⁺), and the control (0 NO₃^-: 0 NH₄⁺). The results showed that ammonium and nitrate improved the growth and physiological status of E. scandens seedlings in most of the treatments compared to the control. The aboveground growth status and biomass accumulation of E. scandens seedlings were significantly better under the 0 NO₃^-: 100 NH₄⁺ treatment during fertilization compared with all other treatments. However, the growth status of the underground parts was not significantly different among treatments. Significant differences in osmoregulator content, except for soluble sugars, and Chl content were observed. Soluble sugars and soluble proteins were highest under the 0 NO₃^-: 100 NH₄⁺ treatment at the end of fertilization (day 175). However, free proline accumulated during fertilization and the increase in NO₃^- indicated that excessive use of NO₃^- had a negative effect on the E. scandens seedlings. The order of accumulating nitrogen content was leaves > roots > stems. The highest N accumulation occurred in the aboveground parts under the 0 NO₃^-: 100 NH₄⁺ treatment, whereas the highest N accumulation occurred in the underground parts under the 50 NO₃^-: 50 NH₄⁺ treatment. Substrate pH increased at the end of fertilization (day 175) compared with the middle stage (day 75), while total nitrogen, ammonium, and nitrate were highly significantly different among the treatments. Total nitrogen and NH₄⁺ content were the highest under the 0 NO₃^-: 100 NH₄⁺ treatment, while NO₃^- content was the highest under the 100 NO₃^-: 0 NH₄⁺ treatment. In conclusion, 12-month-old E. scandens seedlings grew best, and had better physiological conditions in NH₄⁺ than NO₃^-. The 0 NO₃^-:100 NH₄⁺ treatment (ammonium chloride 3.82 g/plant) resulted in the best growth and physiological conditions. Most of the growth and physiological indexes were inhibited with the increase in nitrate.

Erythropalum scandens Bl. is a medicinal woody vegetable found in southern China and parts of Southeast Asia. Studies have shown improper substrate hindered E. scandens seedling growth, causing water accumulation and nutrient deficiency. In pursuit of an ideal growth medium for E. scandens seedlings during the early stages, this study conducted a pot experiment to identify a mixed substrate with optimal water permeability and fertility. In this study, pure Alfisols soil treatment as the control (CK), and two soilless substrates (peat soil and perlite) were combined with Alfisols soil into different volume ratios, in order to better use soil resources from understory space and balance the texture of mixed substrates. The growth, physiological characteristics and nutrient status of 24-month-old E. scandens seedlings were determined after planting in different mixed ratios. The results showed that as the proportion of peat soil increased in the mix, most indexes exhibited an initial increase followed by a decline, while soluble protein content decreased consistently. Conversely, an increasing perlite ratio resulted in a general decline in most growth and physiological indexes. Root growth, biomass accumulation and chlorophyll content, peaked in the 66.67% Alfisols soil + 33.33% perlite (T4) treatment. Notably, T3 (66.67% Alfisols soil + 33.33% peat soil) showcased the best above-ground growth, while T1 (50.00% Alfisols soil + 50.00% peat soil) excelled in element content accumulation. In conclusion, the cultivation substrate should primarily consist of Alfisols soil, constituting at least 50%. The addition of peat soil enhances above-ground growth and nutrients accumulation, while perlite contributes to robust root development. One third of peat soil and a small amount of perlite can be added to the substrate during E. scandens seedling cultivation, and proper fertilization should also be used in order to increase nutrient accumulation in aboveground and underground parts. This research provides valuable insights into maximizing the potential of E. scandens seedlings through precise cultivation methods.

Preventing extinction is one of the greatest challenges facing the global community. Nursery stock breeding is an effective means to restore endangered species, such as Horsfieldia hainanensis Merr., with difficulty in natural regeneration per...

Camellia petelotii (Merr.) Sealy is an endangered Chinese native species that originates from Guangxi Zhuang Autonomous Region, China. Previous research demonstrated that proper water and fertilizer treatments could improve t... | Find, read and cite all the research you need on Tech Science Press

Silicon (Si) plays important role in reducing the toxic effects of manganese (Mn) in plants, however, more research is needed to elucidate the photosynthetic response with different Si and Mn treatments. This study aimed to investigate the alleviating effect of Si on the growth and photosynthesis of Castanopsis hystrix (C. hystrix) under Mn stress. Seedlings were grown in pot experiments with five Mn levels (0, 200, 600, 1500, and 3000 mg·kg^-1) and four Si levels (0, 115, 230, and 460 mg·kg^-1). The results showed that three types of (positive, stagnant, and negative) growth of C. hystrix seedlings were observed among twenty treatments. Low concentrations of Si (Si ≤ 115 mg·kg^-1) and Mn treatments (Mn ≤ 600 mg·kg^-1) can stimulate a positive growth of seedlings by increasing net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs). The 230 mg·kg^-1 Si with low concentration of Mn treatments can cause a stagnant growth of seedlings by increasing Gs, Tr and maximum photochemical efficiency of PSII (Fv/Fm) but decreasing intercellular carbon dioxide concentration (Ci). High concentrations of Si (Si ≥ 460 mg·kg^-1) or Mn treatments (Mn ≥ 1500 mg·kg^-1) treatments can cause negative growth of seedlings by decreasing photochemical quenching (qP), non-photochemical quenching (qN), Gs, Pn and pigment contents. The application of Si alleviated the stress induced by Mn and promoted the growth-defense regulation mechanism of seedlings to avoid stress. Hence, we concluded that the most suitable concentration of Si was 115 mg·kg^-1 Si for C. hystrix’s growth under low Mn stress.