Effects of callus age
Callus rapidly grew across the three tested lines within two weeks of
incubation (Fig. 1b and c), with a significant increase in callus fresh
weight (Table 4). However, variation in callus growth was observed
among the tested lines; SA281 callus grew faster than the other two.
The most rapid callus growth occurred between one and two weeks
as demonstrated by weekly callus growth ratio (the fresh weight of
current week divided by the fresh weight of previous week). Both
regeneration rate and regenerability (shoots per IE) peaked at two
weeks across these three lines (Table 4).