Thesis (BS Biology) -- University of the Philippines Mindanao, 2004

Inflorescence structure, flowers and pollen of three spineless sago palms were examined to explore the potential of sub propagation in preparation for domestication and artificial breeding. One palm could carry up to 1,307,632 flower buds and there are about as many perfect as staminate buds in an inflorescence. Flowers occur in pairs of the staminate and perfect flowers in the bud stage. However, one of the flower buds abscises during development. The staminate buds tend to drop early, thus there are more perfect than staminate flowers left during synthesis. More of the staminate buds left in the spike shortly after anthesis have abnormal (round and triangular) pollen because most of the buds that abscise early are found to have normal (oblong) pollen. Lack of normal pollen and perfect flower drop at the bud stage could partly explain low fruit set (estimated to 0.32 to 1.53%) and high incidence of pathenocarpy in sago. Only normal (oblong) pollens were observed to germinate in vitro. Based on pollen morphology (and viability), ratio of normal to abnormal perfect flowers differs among palms. This could serve as guide for selection of palms for production of seeded fruits. Contrary to earlier reports that all sago taxa produce disulcate pollen, approximately 6% monosulcate pollen was observed in this study. A new dyeing method of microscopic examination of pollen tubes was developed using a combination of modified aniline blue staining and whole mount preparation techniques. The method failed to detect pollen tube growth in pollinated flowers