Each droplet containing one randomly selected
nodal explant was dropped into 250 mL of 1% (w/v)
calcium chloride (CaCl2) solution in a 500-mL beaker.
The solution mix and gel beads were stirred at 100 rpm for
25 min in an orbital shaker at room temperature in order
to induce further polymerization. Soon after washing all
gel beads with autoclaved distilled water several times
in order to remove CaCl2, they were collected on a
metal sieve, placed into sterile 50-mL Falcon tubes, and
kept at 4 °C for 7, 14, 21, 28, 35, or 70 days before they
were recultured onto LS basal medium for 10 days.