3. Results
3.1. Plant morphology
As shown in Fig. 2, during the first half growth period
(0–25 DAS), the average height-growth rate of seedlings from
FLR and R treatments were respectively 6.59 and 5.23 mm d−1,
significantly higher than the others. However, shoot growth
under monochromic R was fragile due to excessive elongation.
Height growth was restrained under B with an average speed of
2.08 mm d−1 which was the lowest among all the light sources
(Fig. 2). Large-sized and compact seedlings with dark green leaves
were detected under FLR and FLB while seedlings with long butthin
stems and light green leaves were obtained under monochromic
R. Moreover, seedlings under monochromatic R looked weak and
creeping, while those under monochromatic B appeared dwarfed
and small similar to those under RB, normal appearance were
observed under FL (Fig. 3).