The endophytic fungi in different tissues of Artemisia annua was isolated and purified to explore their ecological distribution and tissue preference, and the extracellular enzyme activities of dominant endophytic fungi were determined to characterize the metabolic function of endophytic fungi. The results showed that a total of 67 endophytic fungi were obtained from Artemisia annua tissues. The number and species of endophytic fungi in different tissues were significantly different. The number, colonization rate (CR) and isolation rate (IR) of endophytic fungi in root were significantly higher than those of stem and leaf. The dominant endophytic fungi, diversity and similarity coefficient of endophytic fungi also showed significant difference among tissues. The extracellular enzyme activities of endophytic fungi in different tissues are significantly different. The enzyme activities of endophytic fungi isolated from root are significantly higher than those isolated from stem and leaf. The research results showed that the endophytic fungi in Artemisia annua had significant tissue preference, and the metabolic function of endophytic fungi showed significant difference among tissues. This will lay a foundation for further research, development and utilization of endophytic fungi, and also provide a theoretical basis for screening functional endophytic fungi in Artemisia annua.

Molecular characterization of phytoplasmas in original and micropropagated jujube and paulownia samples collected from plants showing witches' broom symptoms was carried out. Ribosomal (16S rRNA) and non-ribosomal genes of the phytoplasma associated with the two diseases were studied after amplification by nested-PCR, using restriction fragment length polymorphism analyses with informative endonucleases. The phytoplasmas infecting paulownia were identified as belonging to ribosomal subgroup 16SrI-D, while those infecting jujube belonged to 16SrV-B. Further molecular characterization show little variability in the other studied genes of these phytoplasmas between original and micropropagated plant material, indicating stability of the population of pathogenic strains of these two phytoplasma when derived from the same original plant.