Propagation of Syzygium malaccense through seed fractionation technique

Syzygium malaccense belonging to the large family of Myrtaceae produces medicinal plant parts and edible fruits which contain high nutritional values and antioxidants. However, the limited occurrence of this fruit species within Malaysia has hindered its commercialization potential. Large-scale planting is necessary to promote this indigenous fruit. A timely supply of sufficient planting materials is needed for this purpose. To date, this tree species is mainly propagated by seeds while stem cutting and grafting techniques are less successful. Although a whole seed has a single plumule-radicle axis, preliminary work showed that a seed could produce more than one plant with its fragmented portions. The cotyledonary fraction devoid of embryo could become regenerative leading to the formation of an entire plant. This phenomenon in S. malaccense could be associated with polyembryony documented in many other members within Myrtaceae. The present study explored seed fractionation as a non-conventional method in the propagation of S. malaccense. The seeds cut systematically into separated halves and quarters were studied for in vivo sprouting potential in a moistened sand medium. The experiment was carried out on germination racks in the laboratory. The results indicated that the reduced reserve did not impact the development of full plants from the seed fractions. The quarter seeds were comparable to the half seeds with a full plant regeneration rate of up to 1.5 while the intact whole seeds had a rate of 0.93. Thus, this simple seed fractionation technique is useful for the multiplication of S. malaccense. Moreover, most of the remaining seed fragments were rooted simultaneously but their shoots were yet to be visible by the end of the study period of five months. Attempts that facilitate the shoot development after adventitious rooting from the fractions through the manipulation of some environmental factors would be beneficial for the propagation of this fruit species. The genetic fidelity of the plantlets originating from a single seed is another research focus in sourcing an alternative for clonal planting materials.