广州地区7种菊科入侵植物丛枝菌根侵染和根际土壤孢子密度的生境差异性分析

为了解广州地区7种菊科(Compositae)入侵植物与丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)的互作共生关系,调查了这7种菊科入侵植物在4种生境中的AMF侵染和根际土壤孢子密度,并分析土壤因子对AMF的影响。结果表明,7种入侵植物根内均受到AMF侵染,根际土壤中均检测到AMF孢子;AMF侵染在宿主间差异显著,生境间的差异不显著;孢子密度在生境和宿主间的差异均显著,人工绿地、农田果园的AMF孢子密度均显著高于森林周边和滨海地带。相关性分析表明,农田果园生境的根际土壤孢子密度与土壤有机质含量呈显著负相关关系;森林周边生境的AMF总侵染率与土壤全氮呈极显著正相关关系;人工绿地的AMF总侵染率与土壤速效氮含量呈显著负相关关系;滨海地带的AMF总侵染率与土壤有效磷含量呈显著负相关关系。这些对理解菊科植物入侵机理具有非常重要的作用。

Habitat Difference Analysis of Arbuscular Mycorrhizal Colonization and Spore Density for Seven Compositae Invasive Species in Guangzhou

In order to understand the symbiosis of arbuscular mycorrhizal fungi (AMF) with Compositae invasive plants in Guangzhou, the AMF colonization rate and spore density of 7 Compositae invasive plant species in four habitats were studied, and the effect of soil factors on AMF was also analyzed. The results showed that all the investigated plants were colonized by AMF, AMF spores were detected from all soil samples. AMF colonization rate showed significant difference among hosts, but not among habitats. AMF spore density was significantly different both among hosts and habitats, among which, spore density was significantly higher in artificial green land, farmland and orchard than that in forest surround and coastal area. Correlation analysis showed that spore density was negatively correlated with soil organic matter content in farmland and orchard, AMF colonization rate was positively correlated with total N content in forest surround, AMF colonization rate was negatively correlated with available N content and available P content in artificial green land and coastal area, respectively. These could play an important role in understanding the invasion mechanisms of Compositae species.