鐵線蕨孢子無菌播種與部分組織培養繁殖系統之建立

Comparative growth and development
of gametophyes and sporophytes were
determined in Adiantum tenerum ‘Scutum
Roseum’ sown in soilless mix and in vitro.
Prothallia in soilless mix were competent to
initiate antheridia provided that these
prothallia had reached a critical size at length
> 1.2 mm and width > 1.3 mm, while
archegonia were observed at prothallia with
length > 2.0 mm and width > 2.5 mm. In
contrast, antheridia were observed in the
young adventitious prothallia cultured in
vitro, with only a few cells. The young
adventitious prothallia were differentiated
from the lower region of the wing cells of the
prothallia after spores were sown in vitro for
20 days. Within sowing for 60 days, the fresh
weight of prothallia increased due to
adventitious outgrowths. The fresh weight of
prothallia increased little and the chlorophyll
content started to decrease after sowing in
vitro for 60 days. The first optimum in vitro
transferring duration was approximately 50
to 60 days after sowing, and the second
subculture was 6 to 8 weeks after the former
transferring. Before transferring from in vitro
to soilless mix, the prothallia soaked with
Johnson’s solution for 5 seconds resulted in a
faster sporophyte formation than those
soaked with 1/2 MS as recommended
previously. The established partial tissue
culture system could facilitate both
mass-propagation of the prothallia and
production of more sporophytes. Regression
analysis revealed that the ethylene production
increased almost linearly up to 0.5-0.6 µL/L
with increasing prothallial fresh weight up to
8-10g per vase. Supplementary GA3 at 0.1-10
mg/L reduced the length and width of
prothallia but promoted the formation of
antheridia, which were observed in the young
gametophytes prior to apical meristem
initiation stage. Increasing GA3 at 100 mg/L
prevented spore germination.