Screening and identification of potassium-dissolving bacteria from different rhizosphere soil of Paris polyphylla var. yunnanensis / 中国中药杂志

The study aiming at exploring the potassium-dissolving capacity of rhizosphere potassium-dissolving bacteria from diffe-rent sources and screen the strains with high potassium-dissolving ability, so as to lay a theoretical foundation for cultivation and quality improvement of Paris polyphylla var. yunnanensis sources. The rhizosphere soil of 10 wild and transplanted species from Yunnan, Sichuan and Guizhou provinces was used as the research object. Potassium-dissolving bacteria were isolated and purified, and their potassium-dissolving capacity was determined by flame spectrophotometry, and identified by physiological, biochemical and molecular biological methods. Twenty-six potassium-dissolving bacteria were purified and 13 were obtained from wild and transplanted strains respectively. It was found through the determination of potassium-dissolving capacity that the potassium-dissolving capacity of 26 strains was significantly different, and the mass concentration of K~+ in the fermentation broth were 1.04-2.75 mg·L~(-1), the mcentration of potassium were 0.01-1.82 mg·L~(-1). The strains were identified as Bacillus, Agrobacterium rhizome and Staphylococcus by physiological, biochemical and 16 S rDNA molecular methods, among them Bacillus amylolyticus(4 strains) was the dominant bacterium of Bacillus. The physiology and biochemistry of rhizosphere potassium-dissolving bacteria in P. polyphylla var. yunnanensis rhizosphere were diffe-rent, and the living environment were different, so the potassium-dissolving capacity also changed. Strain Y4-1 with the highest potassium decomposability was Bacillus amylolytic with a potassium increase of 1.82 mg·L~(-1). The potassium-dissolving ability and the distribution of potassium-dissolving bacteria were different in various habitats. The screening of potassium-dissolving bacteria provided a new strain for the preparation of microbial fertilizer. It is expected that B. amyloidococcus Y4-1 can be used as an ideal strain to cultivate mycorrhizal seedlings of P. polyphylla var. yunnanensis.

Isolation and identification of phosphatolytic bacteria in Paris polyphylla var. yunnanensis / 中国中药杂志

The wild resources of Paris polyphylla var. yunnanensis, a secondary endangered medicinal plant, are severely scarce. Introduction and cultivation can alleviate market demand. To screen phosphatolytic bacteria in the rhizosphere soil of P. polyphylla var. yunnanensis and provide data support for the development of high-efficiency microbial fertilizer, in this study, the dilution plate coating method was used to isolate and screen the phosphorus solubilizing bacteria with the ability of mineralizing organic phosphorus from the rhizosphere soil of wild and transplanted varieties of P. polyphylla var. yunnanensis in 10 different locations in Yunnan, Sichuan and Guizhou. After separation and purification, the phosphatolytic capacity was analyzed by qualitative and quantitative analysis. Combined with physiological and biochemical experiments, the strains were identified using 16 S rDNA sequencing analysis. Forty one strains were selected from the rhizosphere soil of P. polyphylla var. yunnanensis from 10 different habitats. Among them, 21 strains were obtained from the rhizosphere soil of the wild variety P. polyphylla var. yunnanensis and 20 strains were obtained from the rhizosphere soil of the transplanted variety. And significance analysis found that 41 organophosphate solubilizing strains had significant differences in their ability to solubilize phosphorus. The amount of phosphate solubilizing was 0.08-67.61 mg·L~(-1), the pH value was between 4.27 and 6.82. The phosphatolytic amount of strain Y3-5 was 67.61 mg·L~(-1), and the phosphorus increase amount was 57.57 mg·L~(-1). All 41 strains were identified as Gram-positive Bacillus. Combining physiological characteristic and phylogenetic trees, Bacillus mobilis Y3-5 was finally selected as the candidate rhizosphere phosphatolytic bacteria of P. polyphylla var. yunnanensis. The distribution of phosphorus solubilizing bacteria in the rhizosphere soil of P. polyphylla var. yunnanensis was different, and there were significant diffe-rences in phosphorus solubility. Organophosphate-dissolving strain Y3-5 is expected to be a candidate strain of P. polyphylla var. yunnanensis microbial fertilizer.

Effect of Different Nitrogen Forms and Concentrations on Yield and Quality of Fritillaria thunbergii / 中国实验方剂学杂志

Objective:To investigate the effect of different nitrogen forms and concentrations on yield and quality in Fritillaria thunbergii，and provide basis for improving scientific utilization of nitrogenous fertilizer and its introduction to Chongqing area. Method:The pot culture experiment was conducted to investigate the changes in growth，physiological and biochemical characteristics，soil factors，alkaloid content and yield of Fritillaria thunbergii under the ratio of nitrate nitrogen（NO3--N） to ammonium nitrogen（NH4+-N）of 15∶0（N1），12∶3（N2），7.5∶7.5（N3），3∶12（N4） and 0∶15（N5）. Result:As compared with no-nitrogen（CK） treatment group，the growth and quality of F. thunbergii were significantly improved by different nitrogen nutrition treatments，with differences among them.With the increase of ammonium nitrogen concentration：①plant height and the activity of superoxide dismutase（SOD） reached the maximum when the ratio of NO3--N to NH4+-N was 3∶12，increased by 9.27% and 206.62% respectively compared with the CK group，② the length and width of leaf，stem diameter，chlorophyll a，chlorophyll b，total chlorophyll content，the content of available P and organic matter，total alkaloid content and yield reach the maximum when the ratio of NO3--N to NH4+-N was 0∶15，increased by 14.02%，16.44%，13.68%，40.75%，45.31%，41.72%，77.70%，14.70%，24.61%/47.39% respectively compared with the CK group，with the increase of nitrate nitrogen concentration，③the leaf index，soluble protein content，peimisine content/yield，yield of peiminine and dry weight of bulbs reached the maximum when the ratio of NO3--N to NH4+-N was 7.5∶7.5，increased by 2.54%，5.92%，21.76%/54.55%，60.61% and 26.93%，respectively compared with the CK group，④the content of carotenoids，pigment and peiminine，the activity of peroxidase（POD） and catalase（CAT），the content/yield of peimine，both peimine and peiminine，both peimine，peiminine and peimisine，dry weight of bulbs reached the maximum when the ratio of NO3--N to NH4+-N was 12∶3，increased by 45.39%，45.31%，36.01%，271.38%，67.45%，39.82%/64.87%，38.90%/63.80%，37.03%/61.57%，20.29% respectively compared with the CK group. Conclusion:All the results indicated that a higher proportion of NH4+-N is beneficial to the growth of F. thunbergii，while NO3--N is beneficial to the accumulation of alkaloids and the growth of bulbs.Therefore，the combined application of ammonium and nitrate（NO3--N to NH4+-N ratio of 12∶3） is more effective than pure nitrate or pure ammonium applications to improve the yield and quality of F. thunbergii．

Effect of Different Arbuscular Mycorrhizal Fungi on Soil Nutrients in Rhizosphere Soil of Paris polyphylla var. yunnanensis Seedlings / 中国实验方剂学杂志

Objective:To clarify the effect of the arbuscular mycorrhizal （AM） fungi on the rhizosphere soil nutrient content，AM fungi infection rate and total rhizome saponins content of Paris polyphylla var. yunnanensis under symbiosis culture. Method:The changes in the root AM fungi infection rate，rhizosphere soil nutrient content，total rhizome saponins content of P. polyphylla var. yunnanensis and the relationship of the rhizosphere soil factors，the infection rate and the total rhizome saponins content after AM fungi inoculation were analyzed by the method of combining room temperature pot inoculation and data analysis. Result:As compared with the CK group，the root AM fungi infection rate of the AM inoculation group was significantly enhanced （P<0.05），the content of easily extractable glomalin，total glomalin，and total nitrogen increased significantly，while available potassium content and pH significantly decreased. After inoculation with AM fungi，the contents of total phosphorus，available phosphorus，available nitrogen，ammonium nitrogen，nitrate nitrogen，available potassium，and organic matter in the rhizosphere soil of P. polyphylla var. yunnanensis showed significant differences as compared with the CK group. The soil nutrient status was improved，and the total saponin content in the rhizome of P. polyphylla var. yunnanensis was increased. Conclusion:Inoculation with AM fungi can improve the rhizosphere soil nutrient status of P. polyphylla var. yunnanensis，promote the nutrient transformation in the rhizosphere soil，promote the growth of P. polyphylla var. yunnanensis，and improve the quality of medicinal herbs.

Cytotoxic Activities of Total Saponins from Plena Clematis on Human Tumor Cell Lines In Vitro / 中国结合医学杂志

OBJECTIVE@#To investigate the anti-proliferative effects of saponins prepared from Plena Clematis (PC) cultured in Fujian Province, China on 4 human tumor cell lines and its possible anti-tumor mechanism.@*METHODS@#The growth inhibition assays of saponins on human esophageal squamous carcinoma cell line (EC9706), human hepatoma cell line (HepG-2), human oral cancer cell line (KB) and human gastric cancer cell line (BGC-823) were evaluated in vitro by thiazolyl blue (MTT) method. The inhibitory effects on EC9706 treated with different concentrations of saponins (15.62, 31.25, 62.50, 125, 250 and 500 μg/mL) were performed in vitro by MTT method. The morphology and nuclear staining with acridine orange/ethidium bromide of EC9706 cells treated with saponins were illustrated under an inverted phase fluorescence microscope. The apoptotic effects of saponins were further evaluated by annexin-V/propidium iodide dual staining experiment to examine the occurrence of phosphatidylserine externalization onto the cell surface by a flflow cytometer.@*RESULTS@#MTT assay showed that the saponins could inhibit the proliferation of 4 tumor cell lines. Among them, the maximum inhibition rate of 73.1% was detected in EC9706 cells at the saponins concentration of 250 μg/mL for 24 h. Further investigation indicated that the saponins induced EC9706 cells apoposis. The EC9706 cells presented apoptotic characteristics when treated with saponins, including that the morphologies of EC9706 cells were appeared round-shaped with higher refraction, and the cell nuclear stained orange with EB after 250 μg/mL saponins exposure. The flow cytometry analysis results showed that the induction of cell cycle arrest in apoptotic system may participate in the anti-proliferative activity of saponins on EC9706 cells.@*CONCLUSION@#The saponins from PC exhibited significant cytotoxicity against human EC9706, KB, BGC-823, and HepG-2 cells and might be beneficial to development of ethnic pharmaceutical plant for potential anti-tumor drugs.