Plant Diversity ›› 2018, Vol. 40 ›› Issue (03): 117-126.DOI: 10.1016/j.pld.2018.05.001

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N-P fertilization did not reduce AMF abundance or diversity but alter AMF composition in an alpine grassland infested by a root hemiparasitic plant

Xue-Zhao Wanga,b, Xiao-Lin Suib, Yan-Yan Liuc, Lei Xiangb, Ting Zhangb, Juan-Juan Fua, Ai-Rong Lib, Pei-Zhi Yanga   

  1. a Department of Grassland Science, College of Animal Science and Technology, Northwest A & F University, Yangling 712100, Shaanxi, China;
    b Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China;
    c Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, Xinjiang, China
  • Received:2018-03-15 Revised:2018-05-10 Online:2018-06-25 Published:2018-07-13
  • Contact: Ai-Rong Li, Pei-Zhi Yang
  • Supported by:

    The research was financially supported by the Natural Science Foundation of China (U1303201, No. 31400440 and No. 31370512), China Agriculture Research System (CARS-34), Natural Science Foundation of Yunnan Province (2016FB059), Natural Science Foundation of Yunnan Province (2016FB059), and funding for Airong Li from The Youth Innovation Promotion Association of Chinese Academy of Sciences and the Young Academic and Technical Leader Raising Foundation of Yunnan Province (2014HB047).

Abstract:

Fertilization has been shown to have suppressive effects on arbuscular mycorrhizal fungi (AMF) and root hemiparasites separately in numerous investigations, but its effects on AMF in the presence of root hemiparasites remain untested. In view of the contrasting nutritional effects of AMF and root hemiparasites on host plants, we tested the hypothesis that fertilization may not show strong suppressive effects on AMF when a plant community was infested by abundant hemiparasitic plants. Plants and soil samples were collected from experimental field plots in Bayanbulak Grassland, where N and P fertilizers had been applied for three continuous years for control against a spreading root hemiparasite, Pedicularis kansuensis. Shoot and root biomass of each plant functional group were determined. Root AMF colonization levels, soil spore abundance, and extraradical hyphae length density were measured for three soil depths (0-10 cm, 10-20 cm, 20-30 cm). Partial 18S rRNA gene sequencing was used to detect AMF diversity and community composition. In addition, we analyzed the relationship between relative abundance of different AMF genera and environmental factors using Spearman's correlation method. In contrast to suppressive effects reported by many previous studies, fertilization showed no significant effects on AMF root colonization or AMF species diversity in the soil. Instead, a marked increase in soil spore abundance and extraradical hyphae length density were observed. However, fertilization altered relative abundance and AMF composition in the soil. Our results support the hypothesis that fertilization does not significantly influence the abundance and diversity of AMF in a plant community infested by P. kansuensis.

Key words: Arbuscular mycorrhizal fungi, Fertilization, Community structure, Alpine grassland ecosystem, Pedicularis