Diversity of culturable fungi isolated from Coptis chinensis rot root in Shizhu city of Chongqing / 中国中药杂志

Root rot disease restricts the Coptis chinensis industry in Shizhu of Sichuan province. To disclose fungi composition and pathogen in rot root,so as to prevent and treat the root rot disease,the C. chinensis rot root of 5 years from 4 areas in Shizhu were collected in 3 seasons respectively. The fungi were isolated and molecularly and morphological identified,followed with population statistics. 437 fungi were isolated,belonging to 5 subphylum,11 classes,16 orders,22 families and 28 genus respectively. There are great difference among the fungi compositions of different area,year and sampling season,while there was no obvious variation rule. Ilyonectria sp.,Pythium sp.,Phoma sp,Trichoderma sp.are dominant genus,while Pythium sp.,Ilyonectria sp.,Phoma sp.,Fusarium sp. may contain root rot pathogen. Antagonistic bacteria may be screened from the strains of Trichoderma sp. isolated.

Molecular cloning, bacterial expression analysis and functional characterization of pathogenesis-related PR10-2 gene in Panax notoginseng / 中国中药杂志

Base on the transcriptome analysis and RT-PCR techniques,a pathogenesis-related protein 10 gene was isolated from Panax notoginseng root and named as PnPR10-2. Bioinformatics and phylogenetic trees analysis revealed that open reading frame (ORF) of PnPR10-2 was 465 bp in length,encoding 154 amino acids,containing one typical conserved domain of pathogenesis related protein Bet v I family, and showed high similarity with that from P. ginseng. The recombinant expressed plasmid pET32a(+)-PnPR10-2 was expressed in Escherichia coli BL21. The expression conditions were optimized and it could be expressed well in soluble and inclusion body protein. Purified PnPR10-2 recombinant protein from the supernatant of cells was used to analysis the pathogen resistance activity by paper method. The purified recombinant protein could inhibit typical root rot disease pathogen (Fusarium solani and Cylindrocarpon destructans）growth evidently, we conjecture that PnPR10-2 may participated in defense response of P. notoginseng resistance to root rot disease pathogen.

Control of Root Rot and Wilt Diseases of Roselle under Field Conditions

Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.

Evaluation of Antagonism of Penicillium TS67 Against Soy-bean Root Rot Disease and Corn Southern Leaf Blight / 微生物学通报

Through pot experiments, the disease index and control efficiency of TS67 cell, the fermentation liquid of TS67 and the supernatant of TS67 separately act on Fusarium oxysporum and Bipolaris maydis was detected. Experiment results analysis with SPSS statistical analysis software indicated all treatments of TS67 could inhibit both of soybean root rot disease and corn southern leaf blight (P