Three levels of aluminum concentration (AlCl₃・6H₂O) were added to a Kimura B culture solution: 0, 150, and 300 ppm with 3 replications. The culture medium pH of all treatments was adjusted to 3.5. There were no differences in plant height, plant length, or base diameter among the three treatments. No significant difference was seen in the leaf number per plant, leaflet number per plant, leaflet number per leaf, or number of emerged leaves per plant among the three treatments. Root diameters and dry matter weights of roots and whole plants were significantly higher in non-Al-treated (0 ppm Al) sago palms. The number of dead leaves, SPAD value, and chlorophyll content were significantly higher in Al-treated (150 and 300 ppm Al) sago palms. The dry matter weight of leaflets, petioles, and bases were not significantly different among the three treatments. There was marked significant difference in the total leaflet area per plant between 0 and 300 ppm Al. The difference in a single leaflet area was negligible among the three treatments. The relative growth rate (RGR) and net assimilation rate (NAR) tended to be slightly deceased with Al treatments; however, the leaf area ratio (LAR), specific leaf area (SLA), and leaf weight ratio (LWR) showed same levels in all three treatments. Stomatal conductance was significantly lower in Al-treated than in the non-Al-treated sago palms. The photosynthetic rates and transpiration rates were not significantly different with the three treatments. Moreover, the uptake of P, Ca, and Mg was interrupted in the Al treatments; however, N and K uptake were not affected by Al treatment. The root color darkened with Al treatments, and was more distinct with higher Al concentrations. There was a significant difference in the number of root cells per mm2 in the transverse section. From these data, it was clear that sago palm seedlings did not show obvious differences in morphogenesis of the top parts; however, its root diameter and cell differentiation in the cortex of the root were inhibited by high Al concentrations in the media.

View full abstract

 Sago starch samples were collected from Port Moresby of Papua New Guinea (PNG) and Baybay, Leyte, of the Philippines (PLP) to study the polymorph and crystalline disruption of sago starch during gelatinization using corn and potato starch as references. Starch granule suspension was transferred onto a glass slide covered with a cover glass, sealed with nail polish to prevent moisture loss, mounted on a micro-heatplate, and observed using an optical microscope equipped with cross polarizers and a λ-plate. The behavior of sago starch granules during gelatinization was shown by the granular birefringence (Maltese cross) observed under polarized light. The initial, middle, and end gelatinization temperatures determined by a hot stage were, respectively, 78°C, 80°C, and 83°C for PNG sago starch and 76°C, 81°C, and 89°C for PLP sago starch in water. Sago starch still exhibited C-type crystallinity from 60 to 75°C. However, the X-ray diffraction peak at 5 to 6° for 2Θ was observed to decrease, disappearing with increased heating temperature. At 18°, the peaks of PNG and PLP starches began to appear and slightly increase, although the intensity was decreased as a whole. The disappearance of B-type crystallinity from sago starch occurred during gelatinization.

View full abstract