Sprouting and Plantlet Development from Syzygium malaccense Seed Fractions under Different Light Conditions

Abstract

Syzygium malaccense, commonly known as Malay apple or jambu bol, is capable of regenerating entire
plants from its seed fractions and cotyledonary surfaces in vivo. The growth potential exhibited by the seed
fractions sheds light on the possibility of obtaining more planting materials from single seeds through a
simple and practical seed cutting technique. As the cotyledons are mostly green in colour and capable of
assimilating carbon through photosynthesis, the present study investigated the effects of light availability
on sprouting and plantlet development from seed fractions. To obtain quartered seeds as the sprouting
fractions, each seed was cut either longitudinally into approximately four portions or longitudinally into
halves first followed by a transversal cut on each halved fraction to also obtain four approximate quarters.
Then, the separated fractions were sprouted accordingly in the laboratory in moistened sand in enclosed
plastic containers under cool white LED, with natural diffuse light near the windows or in total darkness.
The results revealed that the plantlet development rate from the cotyledonary fractions was the highest with
longitudinal cut seed quarters sprouting in the dark. It was even possible to have four entire plants from the
four longitudinally separated fractions of a seed with this treatment. However, the cotyledonary surfaces
became pale yellowish with sprouting in the dark. The newly emerged plantlets also exhibited etiolated
growth and were also pale yellowish with this dark sprouting procedure. However, the etiolated growth was
reversible where the shoots turned green after the plantlets were exposed to natural diffuse light near the
windows. Overall, the findings provided an option in cultivating and conserving this rare fruit species while
the growth rate and genetic fidelity of the plantlets from different fractions of a seed are the next research
subjects.