In vivo sprouting and growth of plantlets from Syzygium malaccense seed fractions

In vivo regeneration of medicinal Malay apple ( Syzygium malaccense ) through seed fragmentation has been proven successful, especially when sprouted in the dark. With a higher rate of full plant development in comparison to intact seed germination, seed fractions have been suggested for counteracting the regular problem of seedless fruits and heavily predated seeds in the propagation of this tree species. However, the plantlets raised from seed fractions showed varied growth performances. This study systematically determined the growth of plantlets developed from four different seed quarters obtained by cutting a seed longitudinally from hilum to the base of seed. The seeds collected from two different localities were studied. The seed quarters that developed both their roots and shoots in moistened sand in total darkness were then transferred into plug trays containing peat moss to observe their growth performance in partial sunlight. The plantlets were raised with quarter strength Hoagland solution using semi-float system. The results indicate that the seed fractions took varied times to develop their roots and shoots, regardless of origin (locality) of seeds. With measurements taken at two months after respective entire plant development from seed fractions, those that regenerated earlier produced robust plantlets in terms of height and total leaf area. The plantlets grown from fractions that showed late shoot emergence were smaller. On the other hand, there was no relationship between the fraction reserves (weight) and plantlet performance. Genetic analysis of true-to-type plantlets is future work for supporting the feasibility of the propagation of this tree species from seed fractions.