Aspergillus sp., Fusarium sp., and Ramularia sp. were endophytic fungi isolated from Rumex gmelini Turcz (RGT), all of these three strains could produce some similar bioactive secondary metabolites of their host. However the ability to produce active components degraded significantly after cultured these fungi alone for a long time, and were difficult to recover. In order to obtain more bioactive secondary metabolites, the co-culture of tissue culture seedlings of RGT and its endophytic fungi were established respectively, and RGT seedling was selected as producer. Among these fungi, Aspergillus sp. showed the most significant enhancement on bioactive components accumulation in RGT seedlings. When inoculated Aspergillus sp. spores into media of RGT seedlings that had taken root for 20 d, and made spore concentration in co-culture medium was 1 × 104 mL–1, after co-cultured for 12 d, the yield of chrysophaein, resveratrol, chrysophanol, emodin and physcion were 3.52-, 3.70-, 3.60-, 4.25-, 3.85-fold of the control group. The extreme value of musizin yield was 0.289 mg, which was not detected in the control groups. The results indicated that co-culture with endophytic fungi could significantly enhance bioactive secondary metabolites production of RGT seedlings.

Eleuthero (Eleutherococcus senticosus [Ruprecht & Maximowicz] Maximowicz is an important understory species as well as a source of natural products in Asia. The natural source of Eleuthero has been over exploited for pharmacological use, but the manual restoration to rehabilitate its natural distribution has not yet been established. The root is one of the main underground organs in Eleuthero for the acquisition of pharmaceutical ingredients. Root growth also determines the seedling quality of this species for ecological restoration. In this study, Eleuthero seedlings were cultured for one growing cycle with chitosan oligosaccharide (CO) addition at rates of 0 and 25 ppm under artificial lightings by high-pressure sodium (HPS) lamps and two light-emitting diodes (LEDs) with photosynthetic photon flux density set to 94±5 μmol m-2. Light spectra of red (R): green (G): blue (B) ratios were measured to be 43.7:54.6:1.7, 43.8:47:9.2, and 72.7:13.3:14 for the HPS, LED-1, and LED-2 treatments, respectively. In autumn, no interactive effect was found between CO addition and light spectra treatments on any root parameters. Compared to the HPS treatment, the LED-1 treatment resulted in a greater root dry weight and morphology by over 30%. The CO addition caused an increase of root growth by 40-70%. Fine roots in diameter between 0-0.4 mm were the main root part that contributed to the length, surface area, and root tip number. Therefore, LED lighting with the R/G/B spectrum of 43.8:47:9.2 was suggested for the culture of Eleuthero seedlings with the purpose of promoting dry weight and morphology of fine roots.

Non-wood forest products (NWFPs) derived from understory plants are attracting attention about sustainable forestry development. Geographical distribution and climate correlates of bioactive compounds are important to the regional management for the natural reserves of medical plants in forests. In this study, we collected Eleutherococcus senticosus individuals from 27 plots to map the special distribution of concentrations of eleutheroside B, eleutheroside E, and isofraxidin in forests of Northeast China. Compound concentrations in both aerial and underground organs were further detected for relationships with the average of 20-year records of temperature, precipitation, and relative humidity (RH). We found higher shoot eleutheroside B concentration in populations in northern and low-temperature regions (R = −0.4394; P = 0.0218) and in eastern and high-RH montane forests (R = 0.5003; P = 0.0079). The maximum-likelihood regression indicated that both RH (Pr > Chi-square, 0.0201) and longitude (Pr > Chi-square, 0.0026) had positive contributions to eleutheroside B concentration in roots, but precipitation had strongly negative contributions to the concentrations of eleutheroside E (Pr > Chi-square, 0.0309) and isofraxidin (Pr > Chi-square, 0.0014) in roots. Both geography and climate factors had effects on the special distribution of medical compounds in E. senticosus plants in natural populations in Northeast China. The management of NWFP plants at the regional scale should consider effects from climatic geography.

No abstract

In our experiments, one-year-old Larix olgensis seedlings were cultivated in sand, and supplied with solutions with different concentrations of nitrate or phosphate. The effects of nitrogen and phosphorus supply on chlorophyll biosynthesis, total nitrogen content, and photosynthetic rate were studied. The experimental results are listed below: 1) 5-aminolevulinic acid (ALA) synthetic rate increased as nitrate concentrations supplied to larch seedlings increased from 1 to 8 mmol/L. But the rate decreased by 17% when nitrate concentration increased to 16 mmol/L, in contrast to the control. Under phosphate treatments, ALA synthetic rates were similar to those under nitrate treatments. The activities of porphobilinogen (PBG) synthase reached a maximum when larch seedlings were supplied with 8 mmol/L of nitrate or 1 mmol/L of phosphate. 2) When larch seedlings were supplied with 8 mmol/L of nitrate and 0.5 mmol/L of phosphate, the contents of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids reached a maximum. The total nitrogen contents in leaves increased as nitrate concentrations increased. 3) When phosphate concentrations increased from 0.125 to 1 mmol/L, the total nitrogen contents in leaves slightly increased; however, continuous increase of phosphate concentrations resulted in the decrease in total nitrogen contents in leaves. When nitrate concentrations increased from 1 to 8 mmol/L, soluble protein contents in leaves increased in general, and continuous increase of nitrate concentrations induced a decrease in soluble protein contents in leaves. Under treatment of 0.25 mmol/L of phosphate, the soluble protein contents reached a maximum. 4) In general, F v /F m increased as nitrate concentrations increased from 1 to 8 mmol/L, and continuous increase of nitrate concentration resulted in decrease in F v /F m . The similar changes occurred under phosphate treatments. As nitrate concentrations increased from 1 to 8 mmol/L, photosynthetic rates gradually increased, but when nitrate concentrations increased to 16 mmol/L, photosynthetic rate reduced by 16%, in contrast to the control. Photosynthetic rates reached a maximum when seedlings were supplied with 1 mmol/L, and an oversupply of phosphate (2 mmol/L) resulted in decrease in photosynthetic rates. The results suggested that supply levels of nitrogen affected ALA biosynthetic rates, activities of PBG synthase, and affected contents of chlorophyll and carotenoids. Moreover, nitrogen supply levels affected contents of total nitrogen and soluble proteins in leaves, and net photosynthetic rates. ALA biosynthesis rates and activities of PBG synthase were affected by phosphate supply, but contents of chlorophyll and carotenoids were not affected. And net photosynthetic rates were affected little by phosphate supply.