Antifungal effects of three medicinal crops on Phytophthora nicotianae / 中国中药杂志

Tobacco black shank is one of the most harmful soil-borne diseases infected by Phytophthora parasitica. In order to probe the control method to this disease, in this study, the mycelial growth rate method was employed to investigate the antifungal effects of extracts from stem-leaf and root, root exudates, and their combination of Scrophularia ningpoensis, Chuanmingshen violaceum and Pinellia ternata The results showed that: ①Stem-leaf and root extracts of S. ningpoensis, C. violaceum and P. ternata exhibited different antifungal activities, and the inhibition increased with the increase of extract concentration. The antifungal effect of S. ningpoensis extracts at 0.5 g•mL⁻¹ was the strongest than other medicinal plants, the inhibition rate of steam-leaf and root extracts reached 74.88%, 69.27%, respectively. The inhibitory effect of C. violaceum and P. ternata was relatively lower, however, there is a significant gain effect after combination of steam-leaf and root extracts of C. violaceum. ②The root exudates of S. ningpoensis, C. violaceum and P. ternata showed fungistasis to Phytophthora nicotianae, and fungistasis was enhanced with the increase of root exudate concentration. The antifungal effect in the order of C. violaceum > S. ningpoensis > P. ternata. ③The antifungal activity of combination of extract and root exudate from S. ningpoensis was similar with the effect of C. violaceum, they were both stronger than P. ternata, and the antifungal activity for three combination were located between the antifungal activity of their extracts and root exudates. S. ningpoensis and C. violaceum can be potentially applied to prevent and control the tobacco black shank.

Influence of tobacco-Chuanminshen violaceum rotation on microbe community in soil / 中国中药杂志

Soil microbes are the important indicator of soil quality. For exploring Chuanminshen violaceum planting to microbial effects in tobacco soil, this paper adopted Illumina MiSeq high-throughput sequencing to research the change of bacteria and fungi at the phylum and genus in the soil. The results showed that the Ch. violaceum planting increased the biodiversity of bacteria and fungi. The influence on fungi was greater than that on bacteria. It greatly increased the sequence of fungi, it obtained 32 978 16S rDNA and 32 229 18S rDNA sequence number. There was no change of the top three phylums in bacteria, but the content changed, Proteobacteria and Acidobacteria reduced by 1.73% and 1.4% respectively, and Actinobacteria increased by 0.65%. The advantage phylum Ascomycete in tobacco reduced by 27.99% to be second advantage phylum after Ch. violaceum planting, and the second advantage phylum Basidiomycete increased by 23.69% to become the first dominant fungi. At the genus, Ch. violaceum planting changed the order of dominant genus and the abundance was also changed. Some changed largely such as uncultured Acidobacteriaceae Subgroup-1, Gemmatimonas, Subgroup-2,uncultured Nitrosomonadaceae for bacteria, norank Sordariales, norank Agaricomycetes, Phialophora for fungi. Especially the rotation increased antagonistic microbes and physiological microbes and decreased pathogenic microbes. So the Ch. violaceum planting can improve the microbe community in tobacco soil.