J Plant Ecol ›› 2019, Vol. 12 ›› Issue (4): 624-635.DOI: 10.1093/jpe/rty057

• Research Articles • Previous Articles     Next Articles

Effects of clonal integration and nitrogen supply on responses of a clonal plant to short-term herbivory

Bi-Cheng Dong1, , Li-Min Zhang1, Kai-Yu Li1, Xiao-Ting Hu1, Pu Wang2, , Yong-Jian Wang3, , Fang-Li Luo1, Hong-Li Li1 and Fei-Hai Yu1,4,*   

  1. 1 School of Nature Conservation, Beijing Forestry University, Beijing 100083, China
    2 Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    3 College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
    4 Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China
    *Corresponding address. School of Nature Conservation, Beijing Forestry University, Beijing 100083, China. Tel: +86 10 62336683; Fax: +86 10 62336683; E-mail: feihaiyu@126.com
  • Received:2018-03-28 Revised:2018-10-13 Accepted:2018-12-31 Online:2019-01-02 Published:2019-08-01

Abstract:

Aims

Clonal integration, i.e. resource sharing between interconnected ramets, can help clonal plants tolerate abiotic stress. However, few studies have directly examined the ecological significance of clonal integration in the ability of clonal plants to tolerate biotic stress such as herbivory.

Methods

We grew clonal fragments of an invasive clonal plant Alternanthera philoxeroides, each consisting of an apical part (relatively young) and a basal part (relatively old), at two levels (low and high) of soil nitrogen (N). For each fragment, the apical part was subjected to either no herbivory or herbivory for 2 weeks by a specialist insect, Agasicles hygrophila, and was either connected with or disconnected from the basal part not subjected to herbivory.

Important Findings

Herbivory in the apical part severely reduced leaf growth (leaf mass, leaf number or leaf area) and ramet production of both apical and basal parts, and increased root to shoot ratio of the apical part. Irrespective of herbivory and soil N, stem connection between the apical and the basal part decreased root to shoot ratio of the apical part, but did not change its growth measures. Meanwhile, connection increased stem N concentration of the apical part growing under high-N supply and decreased stem carbon (C) concentration of the apical part under low-N supply. By contrast, connection increased root to shoot ratio of the basal part, but reduced its leaf and ramet production. Connection also increased leaf and stem C concentrations of the basal part under low-N supply. Thus, clonal integration can be beneficial for the early development of young A. philoxeroides ramets, but not for their local adaptation to herbivory damage by A. hygrophila.

Key words: Agasicles hygrophila, Alternanthera philoxeroides, foliar herbivory, invasive species, physiological integration