College of Life Science, Hebei University, 180 Wusi East, Baoding, 071002, Hebei Province, China.
College of Plant Protection, Hunan Agricultural University, Changsha, 410128, Hunan Province, China.
Mycorrhiza. 2018 Nov;28(8):703-715. doi: 10.1007/s00572-018-0866-4. Epub 2018 Sep 15.
Invasive species often cause enormous economic and ecological damage, and this is especially true for invasive plants in the Asteraceae family. Arbuscular mycorrhizal fungi (AMF) play an important role in the successful invasion by exotic plant species because of their ability to promote growth and influence interspecific competition. However, few studies have evaluated the effects of invasive Asteraceae species on AMF diversity and how feedback mechanisms during competition with native species subsequently affect the accumulation of nutrient resources. Two exotic Asteraceae, Ambrosia artemisiifolia and Bidens pilosa, were monitored during competition with a native grass species, Setaria viridis, which is being replaced by these exotic species in natural areas around the study site. From these species continuously maintained in a field plot for 5 years, we collected the rhizosphere soil and cloned and identified soil AMF. Furthermore, AM fungal spores were isolated from rhizosphere soil of the two invasive species and used as inoculum in greenhouse experiments, to compare growth and nutrient accumulation during competition. The results indicate that although the AMF diversity in the rhizosphere soil of A. artemisiifolia and B. pilosa differed, the three most abundant species (Septoglomus viscosum, Septoglomus constrictum, Glomus perpusillum) were identical. The addition of AMF inoculum changed the competition between the plants, increasing the competitive ability of the invasives and decreasing that of the native. The results show a similar AMF community composition between A. artemisiifolia and B. pilosa, increased AMF root colonization of the invasive species during competition, AMF-enhanced N accumulation, and AMF-facilitated competitive growth of the invasive species.
入侵物种通常会造成巨大的经济和生态破坏，这对于菊科的入侵植物来说尤其如此。丛枝菌根真菌（AMF）因其能够促进生长和影响种间竞争的能力，在外来植物物种的成功入侵中发挥着重要作用。然而，很少有研究评估菊科入侵物种对 AMF 多样性的影响，以及与本地物种竞争时反馈机制如何随后影响养分资源的积累。两种外来菊科植物，豚草和鬼针草，在与一种本地草种，狗尾草的竞争中受到监测，这些外来物种正在研究地点周围的自然区域取代这些本地物种。从这些在野外连续维持了 5 年的物种中，我们收集了根际土壤，并克隆和鉴定了土壤 AMF。此外，我们从两种入侵物种的根际土壤中分离出 AM 真菌孢子，并将其用作温室实验中的接种物，以比较竞争过程中的生长和养分积累。结果表明，尽管豚草和鬼针草根际土壤中的 AMF 多样性不同，但最丰富的三种物种（光滑球囊霉、束缚丛枝菌、细小无梗囊霉）是相同的。AMF 接种物的添加改变了植物之间的竞争，增加了入侵物种的竞争力，降低了本地物种的竞争力。结果表明，豚草和鬼针草之间存在相似的 AMF 群落组成，竞争过程中入侵物种的 AMF 根定殖增加，AMF 增强了氮的积累，以及 AMF 促进了入侵物种的竞争生长。
