| Summary: | 碩士 === 國立嘉義大學 === 森林暨自然資源學系研究所 === 96 === Formosan pieris (Pieris taiwanensis Hay.), belonging to genus Pieris family Ericaceae, is an indigenous tree species in Taiwan. In this study, its site property, mycorrhizal morphology and associated mycorrhizal fungi in Tataka mountainous area were investigated and isolated; and its roots, stems and leaves were extracted with methanol. The extracts were diluted to make a sequence solutions. These solutions were used to treat wood powders and wood blocks of Taiwan red pine (Pinus taiwanensis Hay.) in order to carry out contact test for antitermitic activity. Furthermore, antitermitic activity of n-Hexane, EtOAc, n-BuOH and H2O-soluble fractions obtained from methanolic extract of leaves were assessed.
The results revealed that the site of Formosan pieris in Tataka were heathland with acidic (pH=4.46) and non-fertile in soil (Ca 2+=1.06 ± 0.10 cmol (+) kg-1, K +=0.19 ± 0.01 cmol (+) kg-1, Mg 2+=0.23 ± 0.03 cmol (+) kg-1, Na +=0.09 ± 0.04 cmol (+) kg-1, N=0.25 ± 0.06 % and P=1.05 ± 0.14 μg/g). The roots of Formosan pieris had typical structure of ericoid mycorrhiza, and the ericoid mycorrhizal fungi were Mycosphaerella genus and Exophiala genus. It’s leaves had the highest methanol extraction rates 32.68±0.8 %. Seven-day averaged mortality rates of Formosan termites (Captotermes formosanus Shirahi) fed on Taiwan red pine wood powders treated with 20,000 ppm methanolic extract of leaves of Formosan pieris had the highest averaged mortality rates 100 %. Thirty-day averaged mortality rates of Formosan termites fed on Taiwan red pine wood blocks treated with 4,000 ppm methanolic extract of leaves of Formosan pieris had the highest averaged mortality rates 100 %. Averaged weight loss rate of wood blocks treated with methanolic extract of leaves of Formosan pieris were 6.03 ± 1.7 %, significantly lower than the methanol control 15.40 ± 3.8 % and water control 16.60 ± 2.4 %. Repellent activity test showed that extracts of Formosan pieris had termite repellent activity. Repellent feed activity test revealed methanolic extract of Formosan pieris had repellent feed activity of termites. The Solid-Liquid partition result shows the averaged mortality rates of Formosan termites fed on Taiwan red pine wood powders treated with EtOAc fraction had the highest averaged mortality rates 100 %, other fractions didn’t show any antitermitic activity. This study demonstrated that methanolic extracts of Formosan pieris had antitermitic activity and the leaves portion had the highest antitermitic activity. And the toxic substances of leaves portion was in the ethyl acetate fraction.
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