Seed germination responses to low-level narrow-band light spectra for 14 ornamental plant genotypes

To investigate whether low-level lighting is necessary and which narrow-band light spectra are effective in seeds germination, of 14 genotypes from begonia, echinacea, gerbera, petunia, vinca were germinated under ultraviolet-B (UVB), blue (B), green (G), red (R), far-red (FR) light, or darkness. Light-emitting diode (LED) fixtures provided all spectrum treatments except for UVB, was by a fluorescent light. The photon flux density at seed level ≈18 µmol m-2 s-1 B, G, R, FR, 0.4 UVB. Based on daily germination observations, final percentage, onset time, time spread, speed compared among different each the plant genotypes. There no promotive effects spread lights to For genotypes, B had similar effect as darkness germination. FR inhibited relative reducing percentage 31–88%, delaying 30–40%, decreasing 11–48% some Under UVB darkness, promoted begonia ‘Apricot Shade’, light-requiring genotype, ‘Burgundy’, light-inhibited genotype. Therefore, low levels used our study unnecessary tested species where most lights.