Effect of Growth Regulators on Clusterd Bud Proliferation and Rooting of Three Phalaenopsis Cultivars

Three Phalaenopsis cultivars, i.e., V31, Sunset Red and Dahonghua, were used for the experiment. Effects of plant growth regulators on the clusterd bud proliferation and rooting of the cultivars were studied. The results showed that in addition to the increase of BA concentration, the bud proliferation rate of the 3 cultivars increased initially, and then, decreased. Optimal NAA concentration in the culture medium could help improve rooting. However, its effects on bud prooliferation and rooting differed with cultivars. For V31, the proliferation increased on the basal medium containing 5.0 mgL-1BA (after 50 d of culture, the proliferation rate was 5.24), while the root growth, on the basal medium with addition of 0.5 mgL-1 NAA. The optimal medium for the Sunset Red was with 7.5 mgL-1 BA to reach a proliferation rate of 2.04 and 0.5 mgL-1 NAA to achieve an effective root induction. For Dahonghua, the proliferation was best improved by the addition of 10.0 mgL-1 BA (the rate was 2.25), and the root growth was best with addition of 1.0 mgL-1 NAA in the medium.