关键词: 内生真菌, 抑菌作用, 相关性, 大戟, 互惠共生

Abstract: With the support of 3S (GIS, GPS and RS) technology and based on recen t 20 years remote-sensing data, the landscape pattern dynamics and desakota reg ion features related with the urbanization of three mega-cities in Asia-Pacifi c Region, i.e., Shanghai (China), Metro Manila (the Philippines), and Hanoi (Vie tnam), were studied by gradient analysis with six landscape matrix indices inclu ding contagion index, largest patch index, landscape shape index, perimeter-are a fractal dimension, patch density, and Shannon diversity index. In the process of urbanization, the regional landscape pattern of the three cities changed mark edly, with an increase of patch density and fragmentation. In land use transects , the patch density and Shannon diversity index had higher correlations with the absolute distance to city center. Landscape index could detect the gradient and the direction of urbanization. The desakota regions of the three cities had dif ferent development features, and the urbanization process of the cities was at d ifferent stages. Metro Manila was found at the highest stage of urbanization, an d with the earliest suburb urbanization and obvious desakota region. Shanghai wa s demonstrated a high degree of urbanization, and an obvious suburb urbanization and desakota region. In contrast, Hanoi had lower level of urbanization and uno bvious suburb urbanization and desakota region. Ecological environment protectio n for the desakota regions should be strengthened.

Key words: Endophytic fungi, Bacteriostasis, Correlation, Euphorbia pekinensis, Mutualism