[Influence of exogenous ginsenosides on new forest soil microbial communities].

Ginsenosides are the main active ingredient and allelochemicals of Panax ginseng, and they play an important role in ginseng growth and in ecological adaptation. To study the influence of ginsenosides on soil microbial communities, the method of given exogenous total ginsenosides of different concentrations were used to study the influence of ginsenosides on new forest soil microbial community, evaluate the change of metabolic activity of microbial community and investigate the ecological effect of ginsenosides on soil microbial community. Results showed that, exogenous total ginsenosides promoted metabolic activity of microbial community in new forest soil at different concentrations compared with the control after 10 d and 40 d treatment. After 10 d,except for the Evenness index, all of the other indices indicated that the functional diversity of the soil microbial community in the new forest firstly increased then decreased with increase of the total ginsenosides concentration. The Substrate richness for 0.01 g•L⁻¹ soil treatment was significantly different from that of the control. After 20 d, 30 d and 40 d, except for the Evenness index, all of the other indices indicated that the functional diversity of the soil microbial community in the new forest increased with total ginsenosides. These results suggested that ginsenosids can change soil microbial community and microbial metabolic activity, which alter soil microbial ecology and accordingly affect the growth of ginseng with accumulation of ginsenosides in the soil.

[Effects of biochar on soil nutrition and microbial community diversity under continuous cultivated cucumber soils in greenhouse]. / ç”Ÿç‰©ç‚­å¯¹æ¸©å®¤é»„ç“œä¸åŒè¿žä½œå¹´é™åœŸå£¤å »åˆ†å’Œå¾®ç”Ÿç‰©ç¾¤è½å¤šæ ·æ€§çš„å½±å“.

In this study, we examined the effects of biochar addition on the soil nutrition and microbial community diversity in continuous cultivated cucumber soils, using 95% soils of planting cucumbers for 6 and 10 years mixed with 5% biochar as treatment and no biochar addition as control, all plants cultivated in the pots. The results showed that adding biochar increased per plant yield of cucumber by 11.4% and 62.8% compared with continuous cropping soil of 6 years and 10 years, respectively. Biochar addition significantly decreased two continuous cropping soils bulk density, increased the content of soil organic matter, available P content, cation exchange capacity (CEC) and soil pH. Meanwhile, biochar addition remarkably improved the abundance of bacteria, ratio of bacteria/fungi, but reduced the abundance of fungi and fusarium oxysporum, which made fungal type soil turn to bacterial type soil. For 10 years continuous cropping soils of adding biochar, the abundance of soil bacteria and bacteria/fungi ratio were 2.00 and 3.64 times to that in the control, respectively, and the abundance of fungi and fusarium oxysporum were decreased by 54.8% and 55.9%, respectively. Biochar addition significantly enhanced soil microbial activities, soil microbial Shannon and McIntosh indexes of 10 years soil by 1.50, 2.14 and 1.31 times, respectively. For continuous cropping soil of 10 years, biochar addition significantly increased microbial utilization abilities of carbohydrate, amino acid, phenolic acid and amine by 1.62, 1.81, 1.74 and 1.93 times, respectively. There were remarkable influences of soil bulk density, available P content, CEC, and pH value to changes of soil microbial community. In conclusion, biochar addition optimized the riphzosphere environment, increased cucumber yield, and alleviated continuous cropping obstacles by improving soil physical and chemical properties, as well as soil microbial community.

Influence of exogenous ginsenosides on new forest soil microbial communities / 中国中药杂志

Ginsenosides are the main active ingredient and allelochemicals of Panax ginseng, and they play an important role in ginseng growth and in ecological adaptation. To study the influence of ginsenosides on soil microbial communities, the method of given exogenous total ginsenosides of different concentrations were used to study the influence of ginsenosides on new forest soil microbial community, evaluate the change of metabolic activity of microbial community and investigate the ecological effect of ginsenosides on soil microbial community. Results showed that, exogenous total ginsenosides promoted metabolic activity of microbial community in new forest soil at different concentrations compared with the control after 10 d and 40 d treatment. After 10 d,except for the Evenness index, all of the other indices indicated that the functional diversity of the soil microbial community in the new forest firstly increased then decreased with increase of the total ginsenosides concentration. The Substrate richness for 0.01 g•L⁻¹ soil treatment was significantly different from that of the control. After 20 d, 30 d and 40 d, except for the Evenness index, all of the other indices indicated that the functional diversity of the soil microbial community in the new forest increased with total ginsenosides. These results suggested that ginsenosids can change soil microbial community and microbial metabolic activity, which alter soil microbial ecology and accordingly affect the growth of ginseng with accumulation of ginsenosides in the soil.

Rhizosphere microorganism evidence on geo-authentic features of traditional Chinese medicine from Moutan (Paeonia suffruticosa) / 药学学报

Paeonia suffruticosa also named Moutan that cultivated in five geographic regions during different growth stages were chosen in this study. Biolog and 454 pyrosequencing technology were used to detect the whole microbial activity and fungal diversity for exploring the relationship between the geo-authentic features of the medicinal plant and the rhizosphere microorganism. The results suggest that the value of average well color development (AWCD) from the rhizosphere soil of P. suffruticosa in the five regions at the fo ur growth stage have an increasing tendency. 9 703 operational taxonomic unit (OTU) were obtained from 272 463 high quality sequences according to the similarity of 97% by the pyrosequencing. Fungi in five phyla, twenty-two classes, seventy orders, one hundred and thirty-nine families and two hundred and sixty-six genera were detected in the five regions excluding twelve percent to fifty-eight percent unidentified fungi. They were divided into four branches, i.e. Blastocladiales, Chytridiomycota, Dikarya and Glomeromycetes. Twenty-four genera such as Leptosphaeria were found in the five regions while six genera such as Curvularia were only detected in the geo-authentic regions. The dominant genera were Guehomyces, Exophiala and Fusarium in geo-authentic regions, whereas genus Leptosphaeria, Cryptococcus, Exophiala, Fusarium and Ceratobasidium in non-authentic regions. The results from principal co-ordinates analysis (PCoA) showed that the fungi formations were similar in Tongling and Nanling region at four different growth stages, and the same in Heze at the leaf bud and fruiting stage. According to heatmap analysis, Tongling and Nanling region showed a close similarity in fungal community structures on phylogenetic analysis, while Bozhou, Heze and Luoyang showed the same. In brief, the whole microbial activity was higher in geo-authentic regions than the non-authentic. Fungi in rhizosphere soil of the medicinal peony presented diversity and region specificity. We found not only the abundant new species in the five regions, but also the phylogenetic similarity in the geo-authentic regions.