Callus induction from young leaf explants of nipa (Nypa fruticans Wurmb.)

The micropropagation of nipa through plant tissue culture using young leaf explants was tested for callus induction. The objective of this study was to develop optimum sterilization protocol and suitable levels of 2,4-Dichlorophenoxyacetic acid for successful callus induction. The explants (0.5 cm) were tested with ten different sterilization solutions in three different soaking periods. Using 19 mL commercial bleach-81 mL distilled water and 3% H2O2 for 20 minutes to surface-sterilize the leaf explants was determined as the best treatment. Explants from germinated seedlings were cultured in MS media fortified with 2,4-D (20, 40, 60, 80 and 100 AM) and 1.5 g.L(-l)Activated Charcoal (AC). After 12 weeks, whitish and spongy callus grew in cultures with 20 mu M 2,4-D (44% callus formation). In the same manner, explants from immature leaflets of young nipa palm also produced callus but induced yellow and globular growth. The second set-up took 8 weeks for callus to grow in 40 mu M 2,4-D with 33% callus formed. These levels of 2,4-D as auxin together with AC, can induce callus even without the presence of cytokinins. These results provide many opportunities for mass clonal propagation of disease-free planting materials, breeding, and cellular and histological analysis as well as baseline information for further investigations of this underutilized palm.