high tolerance to salinity and herbivory stresses may explain the expansion of ipomoea cairica to salt marshes高耐盐度和食草性压力可以解释的扩张番薯cairica盐沼.pdfVIP

High Tolerance to Salinity and Herbivory Stresses May Explain the Expansion of Ipomoea Cairica to Salt Marshes 1 1,2 1 1 1 1 Gang Liu , Qiao-Qiao Huang , Zhen-Guang Lin , Fang-Fang Huang , Hui-Xuan Liao , Shao-Lin Peng * 1 State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China, 2 Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, China Abstract Background: Invasive plants are often confronted with heterogeneous environments and various stress factors during their secondary phase of invasion into more stressful habitats. A high tolerance to stress factors may allow exotics to successfully invade stressful environments. Ipomoea cairica, a vigorous invader in South China, has recently been expanding into salt marshes. Methodology/Principal Findings: To examine why this liana species is able to invade a stressful saline environment, we utilized I. cairica and 3 non-invasive species for a greenhouse experiment. The plants were subjected to three levels of salinity (i.e., watered with 0, 4 and 8 g L21 NaCl solutions) and simulated herbivory (0, 25 and 50% of the leaf area excised) treatments. The relative growth rate (RGR) of I. cairica was significantly higher than the RGR of non-invasive species under both stress treatments. The growth performance of I. cairica was not significantly affected by either stress factor, while that of the non-invasive species was significantly inhibited. The leaf condensed tannin content was generally lower in I. cairica than in the non-invasive I. triloba and Paederia foetida. Ipomoea cairica exhibited a relatively low resistanc