3. Results
3.1. Effects of different substrates on scale cutting propagation
The percentage of rotten scales was notably different in the
four substrates (Table 2). Among the four substrates, peat resulted
in the highest rotting level, while sawdust had the lowest level.
After incubation for 100 days, the percentage of bulblet induction
and the diameters and fresh weights of bulblets in sawdust were
notably higher than that in other substrates (Figs. 1 and 2A). By
100 days, independent of the substrate, almost all the outer scales
had become exhausted, and the inner scales became transparent
and senesced from the basal plate. Sawdust was the most optimal
substrate for scale cutting propagation of H. vittatum under our
experimental conditions.
3.2. Effects of different temperatures on scale cutting propagation
3.2.1. The rate of rotten scales and sprouting bulblets
The percentage of rotten scales at 30 ◦C was notably higher than
that at 25 and 20 ◦C (Table 3). The bulblets formed early at 30 ◦C.
After incubation for 25 days at 30 ◦C, the percentage of bulblets
formation was 8.3%, while no bulblets had yet formed at 25 and
20 ◦C (Table 3). As the culture period was extended to 50 days, the
percentage of bulblet formation at both 20 and 25 ◦C increased considerably
and was significantly higher than at 30 ◦C, a result that
was sustained until 75 days.
3.2.2. Effects of different temperatures on bulblet size
After 50 days’ culture, the diameter and fresh weight of bulblets
at 30 ◦C were notably higher than at 20 and 25 ◦C while after 75 days
culture, and there was no marked differences between 25 and 30 ◦C,
although the diameter and fresh weight of bulblets were remarkably
higher than at 20 ◦C (Fig. 1). Between 75 days to 100 days
incubation, the diameter and weight of bulblets at 25 ◦C increased
most (Fig. 2C), with only modest changes at 30 ◦C. After 100 days,
the diameter and fresh weight of bulblets at 25 ◦C were significantly
higher than other treatments (Figs. 1 and 2B).
3.3. Effects of plant growth regulators on scale cutting
propagation
GA3, IBA and NAA at different concentrations were all not
conducive to scale propagation (Fig. 2D). The scales treated with
GA3 produced neither roots nor bulblets (Fig. 2D1) and the starch
content showed only a very slight change during the entire incubation
period (at the initial incubation stage, starch content in
inner and outer scales of propagules was 198.45 and 195.63 mg g−1,