马齿苋内生菌橘青霉和波兰青霉中抗青枯菌的活性物质

为了挖掘农作物病害生物防治新资源,以药用植物马齿苋(Portulaca oleracea)为材料,通过培养基种植法分离和纯化其根、茎、叶中的内生菌,以青枯菌(Ralstonia solanacearum)的抑菌试验评价其活性,采用菌落形态观察和ITS序列分析鉴定菌种。结果表明,从马齿苋筛选出2种具有抑制青枯菌的内生菌橘青霉(Penicillium citrinum)和波兰青霉(P. polonicum),采用液相与四极杆飞行时间串联质谱(UPLC-QTOF-MS)鉴定2种内生菌的主要活性物质为橘霉素,其对青枯菌的抑制效果比链霉素更好。因此,这为植物青枯病的生物防治提供科学依据。

Bioactivity Metabolite from the Endophytics Penicillium citrinum and P. polonicum of Portulaca oleracea Against Ralstonia solanacearum

To investigate the diversity of endophytics in medicinal plant Portulaca oleracea and explore potential biological resources to prevent and control crop diseases, the endophytes from its roots, stems and leaves were isolated by medium cultivation method, their bioactivities were evaluated against Ralstonia solanacearum, and they were identified by colonial morphology and ITS sequence. The results showed that the crude extracts of two endophytics Penicillium citrinum and P. polonicum displayed strong activities against the phytopathogen R. solanacearum. One of active metabolite (citrinin) was identified based on UPLC-QTQF-MS. Moreover, the activity of citrinin had more strong antibacterial property than that of streptomycin, which was a common agent in agriculture to prevent bacterial wilt. So, these would provide scientific basis for biological control of bacterial wilt.