Effects of temperature and humidity on infection of Fusarium oxysporum in seedlings of Salvia miltiorrhiza / 中国中药杂志

Wilt disease is a major disease of cultivated Salvia miltiorrhiza, which is caused by Fusarium oxysporum. Since the infection process of F. oxysporum in plants is affected by environment factors, this study was conducted to reveal the relationship between disease severity and concentration of the pathogen in plants in the infection process of F. oxysporum in seedlings of S. miltiorrhiza by pot experiments and to reveal the effects of temperature and humidity on the infection process. The results showed that, after inoculation of S. miltiorrhiza seedlings with F. oxysporum, the pathogen in different parts was detected at different time, and it was first detected in substrates. With the continuous propagation of the pathogen(4-5 d), it gradually infected the roots and stems of the seedlings, and the plants had yellowing leaves and withering. The number of the pathogen reached the maximum in each part after 7-8 d, and then gradually decreased in the later stage of the disease. The concentration of the pathogen in substrates, roots and stems of S. miltiorrhiza showed a trend of decreasing after increasing with the aggravation of the disease and reached the maximum in the samples of moderate morbidity, while the concentration in the samples of severe morbidity decreased. In addition, the infection of F. oxysporum in seedlings of S. miltiorrhiza was affected by temperature and humidity. The suitable temperature was 25-30 ℃ and the suitable humidity was 80%-90%. This study could provide guidance for the experiments on pathogenicity of F. oxysporum, screening of biocontrol bacteria and controlling of wilt.

Effect of different fungicides on efficiency of mycorrhizal symbiosis on Salvia miltiorrhiza / 中国中药杂志

Arbuscular mycorrhizal fungi provided is beneficial to Salvia miltiorrhiza for increasing yield, promoting the accumulation of active ingredients, and alleviating S. miltiorrhiza disease etc. However, the application of fungicides will affect the benefit of arbuscular mycorrhizal fungi and there is little research about it. This article study the effect of four different fungicides: carbendazim, polyoxin, methyl mopazine, and mancozeb on mycorrhiza benefit to S. miltiorrhiza by the infection intensity of arbuscular mycorrhizal fungi, the growth of S. miltiorrhiza, and the content of active ingredients. RESULTS:: showed that different fungicides had different effects. The application of mancozeb had the strongest inhibitory effect on the mycorrhizal benefit to S. miltiorrhiza. Mancozeb significantly reduced the mycorrhizal colonization and the beneficial effect of arbuscular mycorrhizal fungi on the growth and the accumulation of active components of S. miltiorrhiza. The application of polyoxin had no significant effect on mycorrhizal colonization. Instead, it had a synergistic effect with the mycorrhizal benefit to promoting the growth and accumulation of rosmarinic acid of S. miltiorrhiza. The inhibitory strengths of four fungicides are: mancozeb>thiophanate methyl, carbendazim>polyoxin. Therefore, we recommend applying biological fungicides polyoxin and avoid applying chemical fungicides mancozeb for disease control during mycorrhizal cultivation of S. miltiorrhiza.

Cloning and expression analysis of 3-hydroxy-3-methylglutaryl coenzyme A reductase (CcHMGR) genes in Cinnamomum camphora (L.) Presl / 药学学报

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is the first rate-limiting enzyme of terpenoid biosynthesis in the mevalonic acid pathway (MVA) pathway. It is an important regulatory site in terpenoids metabolism pathway in the cytoplasm. According to the transcriptome database of Cinnamomum camphora, two HMGRs named CcHMGR1 (GenBank: MN163055) and CcHMGR2 (GenBank: MN163056) were cloned by cDNA from C. camphora. The ORF of CcHMGR1 and CcHMGR2 is composed of 1 689 bp and 1 683 bp, respectively, encoding 562 and 560 amino acids. The bioinformatics analysis of CcHMGR1 and CcHMGR2 indicated that the molecular weight of the encoded protein is 59.819 kDa and 59.397 kDa, with a theoretically isoelectric point of 8.20 and 8.61, respectively. There are 2 transmembrane structures without signal peptide existing in the encoded amino acid of CcHMGRs. The analysis of sequence alignment and phylogenetic tree showed that theCcHMGRs belonged to the HMGR family. The camphor is divided into five chemitypes, according to the main chemical compoundsin C. camphora. The results of the real time PCR indicated that the expression level of CcHMGRs in Cineol type was higher than that in Linalool type, iso-nerolidol type, Camphor type and Borneol type. CcHMGRs expressed highest in roots and lowest in branches. In this study, the cDNA full length of CcHMGRs were cloned from C. camphora for the first time. Our results revealed that the expression level of CcHMGRs were different among five chemical types and different plant tissues, and the research provides foundation for further study of the terpenoids biosynthetic pathway in C. camphora.

Effect of soil pH on efficiency of mycorrhizal symbiosis on Salvia miltiorrhiza / 中国中药杂志

By comparing the effects of soil pH on the efficiency of mycorrhizal symbiosis on Salvia miltiorrhiza， the study is aimed to provide guidance for the use of mycorrhiza in the cultivation of S. miltiorrhiza. In this experiment, the inoculant treated and the non-inoculant treated control were grown in different soil pH. The data was collected after 60 days of cultivation including rate of mycorrhizal infection, biomass, and three chemical constituents with known medicinal action. The results showed that Glomus versiforme was more apt to infect S. miltiorrhiza (F>94.00%; M>69.45%; m>73.66%) and promote the growth of S. miltiorrhiza under pH 5-9 soil. The mycorrhizal contribution to the growth of S. miltiorrhiza was the highest when grown in pH 8 soil. Plants grown with mycorrhiza in pH 8 soil had above-ground biomass more than 2 times and root biomass more than 5 times. The uninoculated plants grew better under acidic and neutral conditions, but the inoculated plants grew better under alkaline (pH 8) conditions. This result showed mycorrhiza can play a role in the adaptability of S. miltiorrhiza to the environment. Inoculation of mycorrhiza significantly increased the accumulation of rosmarinic acid, salvianolic acid B, and dihydrotanshinone by 6.59,5.03 and 2.20-folds. Based on our results alkaline soil (pH 8) is most suitable for the cultivation of S. miltiorrhiza by inoculation with the mycorrhiza G. versiforme.