Chiang Mai Journal of Science

The effectiveness of various combinations of light-emitting diode (LED) spectra on the in vitro growth of two sugarcane cultivars, KK3 and LK, was investigated. Three steps of micropropagation were investigated: 1) callus induction from young rolled leaves cultured on solid Murashige and Skoog (MS) medium supplemented with 3 mg/L 2,4-dichlorophenoxyacetic acid and 10% coconut water; 2) shoot regeneration from callus cultured on solid MS medium supplemented with 10% coconut water; and 3) the tiller shoots proliferation from in vitro plantlet cultured on MS medium with or without 10% coconut water. Callus induction under blue LEDs followed by shoot regeneration under blue+red LEDs resulted in the highest number of regenerated shoots in KK3 (321.33 shoots/callus clump) followed by callus induction under blue+red LEDs followed by shoot regeneration under white+red LEDs (310.67 shoots/callus clump). In LK, the application of blue+red LEDs during callus induction followed by shoot regeneration under white+red LEDs yielded the highest number of regenerated shoots of 232.33 shoots/callus clump. In contrast, the control treatment—where callus was induced in darkness and shoot regeneration was performed under a white LED alone—produced only 49.00 and 64.33 shoots/callus clump in KK3 and LK, respectively. Furthermore, the white+red LEDs significantly enhanced tiller proliferation in ‘KK3’. However, tiller proliferation in ‘LK’ was not significantly affected by light spectrum.