Rapid Propagation for Hudson Foster Grapefruit Using Its Stems on Tissue Culture

Stem segments of adult Hudson Foster grapefruit plants were used as explants to study the effect of hormones on the primary culture of axillary shoots, as well as that of hormones and media on the proliferation of clustered shoots. In addition, an attempt was made to refine the techniques on rooting, hardening and transplanting of the plantlets. The results showed that :(1) the optimized medium for primary culture was WPM+1.0 mg·L^-1 6-BA/L+0.2 mg·L^-1 NAA/L+40 g·L^-1 to achieve up to 78.33% induction rate of axillary shoots; (2) the optimized medium for subculture multiplication was WPM+0.75 mg·L^-1 6-BA+0.2 mg·L^-1 NAA+40 g·L^-1 sucrose to reach a multiplication coefficient of 4.93 with a shoot length of 2.62 cm; (3) the optimized medium for rooting was 1/2WPM+0.1 mg·L^-1 NAA+1.0 mg·L^-1 IBA+40 g·L^-1 sucrose+0.1% AC to obtain strong roots at a rooting rate of 63.33% with a plant height up to 3.03 cm; (4) the survival rate of transplanted plantlets after rooting was greater than 78%.