Research On Biseratae Against Citurs Storage Pathogens

Citrus, as one of the most important fruits in the world, is easy to fall into decay during storage and transportation for the reason of disease infections, which caused considerable economic losses. To resolve these troubles, many chemosynthetic antistaling agents were used. However, these agents were usually harmful to people's health. Therefore, finding antibacterial substances from the plants is becoming a hot point. In this paper, a serial researches including extracts'antibacterial activity, extracting and structure identification of active material and the theory on antibacterial were carried out on Biseratae and other 50 plants to provide some basis for the development of botanical fungicide. The mainly experimental results were listed as follows:1.51 plants were extracted using the ultrasonic extraction. The inhibiting activity of these extracts to 4 types of citrus storage diseases were assayed by measuring the mycelium growth rate.7 plant including Cortex Acan thopanacis Gracilistyli,Ligusticum Sinense,Ligusticum chuanxiong, Radix Angelicae Biseratae and etc. showed inhibiting activities to Penicillium, green mold, anthrax and sour bacteria, and the inhibition rate of Radix Angelicae Biseratae is very high and is 84.97%,82.5%,98.92%,94.38% respectively at 5mg/mL concentration. Radix Angelicae Biseratae ethanol extract has good preventive effect to storage pathogens of citrus and does not have negative effect to citrus. The preventive effect rate of Radix Angelicae Biseratae ethanol extract against P. italicum and P.digitatum is up to 35%. The preventive effect of Radix Angelicae Biseratae ethanol extract to C.gloeosporioides the inhibition rates of extract against C.gloeosporioides is 80%, and the total preventive effect rate is 70%.2. Five active ingredient designed as A, B, C, D and E were obtained by extraction using different polarity solvent in the extract of Radix Angelicae Biseratae. And B is significantly different from the other four ingtedients. The inhibition ability of B against C.gloeosporioides is high up to 95.38%(1 mg/mL). And then 6 kinds of active ingredient were separated from B by column chromatography, No.2 own the best effect against C.gloeosporioides, and the inhibition rate is up to 83.15% at 0.5 mg/mL, The EC50 is 0.1452 mg/mL. According to GC-MS analysis, Isobergapteo, Pimpinellin, Sphondin and Isopimpinellin were found.3. By observing the morphology of C.gloeosporioides and P.digitatum hypha, we find that Radix Angelicae Biseratae ethanol extract can make pathogen cell wall surface become rough, the distance between separates shortened, vacuole larged or decreased or become smaller, hyphal branching increased and even branch office distorted and so on.4. By investigating the effect on four kinds of enzyme activities after ethanol extraction to Rdigitatum and C.gloeosporioides, we find that Radix Angelicae Biseratae ethanol extract have high effect to C.gloeosporioides laccase,guaiacol oxidaseand pyrocatechol oxidase, but have no effect to cellulose. These suggest that Radix Angelicae Biseratae ethanol extract have Inhibition effect to P.digitatum and C.gloeosporioides lignin activity metabolism but the effect on the metabolic pathway of cellulose need to be furthered analyzed.5. The Radix Angelicae Biseratae extracts Rdigitatum SDS-PAGE analysis showed that extract from Radix Angelicae Biseratae influence the proteins of Citrus Green Mold pathogen. Some different protein bands came out and the protein bands of R3 and R11 disappeared. The results might tell us that the Radix Angelicae Biseratae extracts cause the digestion of some certain proteins, and these proteins are related to cellulose acitivity.