Enhanced Growth, Water Use Efficiency and Soluble Sugar of Drought-Stressed Trifoliate Orange Seedlings Inoculated with Mycorrhiza

摘要

A pot experiment was conducted to examine the effects of arbuscular mycorrhizal fungus (AMF), Glomus mosseae, and drought stress on growth, soluble sugar content, and water use efficiency (WUE) of trifoliate orange (Poncirus trifoliata) seedlings. After 2 weeks of inoculation, drought stress began and maintained at 60-65% of maximal field capacity for 106 days. Drought stress did not significantly decrease AMF colonization. Mycorrhizal seedlings maintained significantly higher soluble sugar contents of leaf and root whether drought stressed or not. AMF seedlings also recorded notably higher plant dry weight under the conditions of ample water. AMF colonization significantly increased the WUE of the seedling by 40% under ample water conditions and by 43% under drought stress conditions, implying that the AMF plants use less water to produce one unit of plant biomass than non-AMF plants. It suggests that G. mosseae-inoculation would enhance drought tolerance of trifoliate orange seedlings.