Two months old seedlings of Taiwania inoculated either with Glomus mosseae or Acaulospora laevis or a mixture of both were cultivated in greenhouse for four months. They were then transplanted to soils of different moisture content of 20%, 40%, or 60% and allowed to grow for additional 18 months. Their growth response was examined.
Results showed that low soil moisture content inhibits the growth of seedling without inoculation but not that of inoculated ones. Both low (20%) and high (60%) moisture content decreased the infection rates. The inhibition effect of the former is greater than that of the latter. Soil water stressed seedlings inoculated with G. mosseae performed better than those inoculated with A. laevis. The growth performance of seedlings inoculated with a mixture of both fungi spp. lay between that of seedlings which were inoculated with respective fungus alone. These results suggested that, in mycorrhizal association, different fungi may function differently and that when using mycorrhizal inoculation to enhance the host plant tolerance/resistance to the water stressed environment of planting site, selection of proper inoculants is critical to the success of the planting programs.
Key words: Taiwania cryptomerioides, mycorrhizae, soil moisture content.