SAGO PALM 8-1, 2-8 (2000)
Key words: leaf position, leaflet, palm age, stomatal density, stomatal length
Abstract:
This study was undertaken to investigate the sotomatal
density in leaflets of sago palm, a tropical starch crop, to gain some
fundamental knowledge related to photosynthesis of the leaves. 1) To investigate
the stomatal density at different parts on leaflets attached to lower,
middle and upper positions in one leaf, leaves on the lower, middle and
upper parts of plants were sampled from the palms at trunk formation stage
(about 5-years old) in a farmer's sago garden in Tebingtinggi Island in
Riau, Indonesia. The tip part of a leaflet had lower stomatal density than
basal or middle part, and abaxial surface had higher stomatal density (550
- 750/mm2) than abaxial
surface (100 - 250/mm2).
Stomatal density of both sides on a leaflet showed a tendency to decrease
from base to tip part with the decrease in thickness. Little difference
was observed in the stomatal densities among leaves and leaflets at different
positions in a plant and in one leaf, respectively. 2) To investigate the
change of stomatal density by palm age, leaflets on the middle position
in leaves of middle part of 1- to 5-years old palms were sampled in a farmer's
sago garden in Muka, Sarawak, Malaysia. Stomatal density of abaxial surface
markedly increased from 1- to 3- years old (400 - 900/mm2),
however, it gradually increased thereafter and attained almost the definite
value (1000/mm2) at 5-years old, trunk formation stage. In abaxial surface,
the stomatal density also increased with aging of palms, but the density
(50 - 120/mm2) is
significantly smaller than that of abaxial surface (400 - 1000/mm2),
irrespective of palm age.