Effect of culture duration and number of cycles of multiplication
on embryo induction. The normal culture duration for
banana shoot cultures was found to be about 30 d. Regular
subculturing at 4-wk intervals was required to maintain
cultures in an actively growing state. When culture duration
was increased from 30 to 90 d, embryo induction took a
longer time (Table 4). Also, the percentage of explants
responding reduced from 100% to 83% in 60-d-old explants
and 66% in 90-d-old explants. Similarly, the number of
embryos formed per explant also showed a drastic reduction
(355 embryos per explant from 30-d-old cultures to 50
embryos per explant from 90-d-old cultures) with increased
culture duration of the explants.