Thesis (BS Biology) -- University of the Philippines Mindanao, 2008

The reproductive biology, pollen and seed longevity of the endangered Philippine pitcher plant, Nepenthes truncate, were studied through observation and experiments in its natural environment in Davao City, Mindanao Philippines at lat 70 45? N, long 1250 24? E, 1177 m.a.s.l. and in the laboratory. A total of 37 plants, 28 males and 9 females, were observed over a 12-month period. Flowering of the male and female plants was synchronous in the months of March, April and May, apparently triggered by a dry period, and in August, apparently triggered by long daylength. Each male or female plant produced one raceme, which have bifurcate pedicels bearing the florets. All of 272 florets in one male inflorescence matured in a progressive upward direction within 12.67 weeks from inflorescence emergence; and more or less simultaneously within 2 weeks from the bud stage of 112 florets in the female inflorescence. On the average, there were 443,333 tetrasporangiate pollens per male floret. Pollen remained viable for 48 hours at 3 0C in Petri plates with moist tissue paper. Pollen germination and vigor increased with floret maturity. Stigma receptivity, which can be judged by the green color, was highest at anthesis dropping to 56% after 48 hours. Bees, ants, spiders, Lepidoptera and Diptera were found in and around the plant which may be agents of pollination. Seeds were borne on capsules with an average of 11,065 seeds per inflorescence. Seeds germination rate higher than 70% can be maintained up to 4 months in both room and refrigerated conditions as long as they are kept dry in storage