Effect of Cutting Types and Leaf-retention on Rooting and Photosynthesis Propagating of Syzygium samarangense Cuttings

Three types of cuttings and leaf-retention on a cutting branch of Syzygium samarangense were applied to study their effects on the survival rate,rooting and photosynthesis of the cuttings for propagation. The intelligent monitoring and controlling of agermchit rapid propagation system was used for the experimentation. The results showed that the survival rate of the green-colored cut branches was the highest;while those in brown color, the lowest. There were only minute differences between the green and the green-brown cuttings on the number, diameter, or length of the roots developed, but significant differences existed between the green and the brown cuttings, with the brown branches being the least among the three kinds of branches. The leaf-retention on a cutting branch affected significantly the rooting and survival rate of the cuttings for propagation. The highest survival rate and rooting ratesoccurred when 2 to 4 or 3 to 4 leaveswere allowed to remain on a cutting branch.But, none of the cuttings without any leaf survived the process. The content and fluorescence (i.e., effective quantum yield of photosystem) of chlorophylldid not differsignificantly between the green and the green-brown cuttings, regardless how many leaves were allowed to remain on them. For the brown cuttings, their chlorophyll content and yield were higher if 2 to 4 leaves were left on a cutting than other treatments.It was concluded that the green or green-brown cutbranches with 2 to 4 or 3 to 4 leaves remained on each cutting were best for the propagation of S. samarangense by means of cutting.