Journal Article

Effects of LED photoperiods and light qualities on in vitro growth and chlorophyll fluorescence of Cunninghamia lanceolata

Liu, Shinan, Xu, Yuanyuan, Liang, Yuyao, Yang, Mei, Cheng, Fei

2020

Overview

Background Cunninghamia lanceolata (C. lanceolata) is the main fast-growing timber species in southern China. As an alternative to conventional lighting systems, LED has been demonstrated to be an artificial flexible lighting source for commercial micropropagation. The application of LED can provide rapid propagation of C. lanceolata in vitro culture. Results We applied two-factor randomized block design to study the effects of LED photoperiods and light qualities on the growth and chlorophyll fluorescence of C. lanceolata in vitro culture plantlets. In this study, plantlets were exposed to 20 μmol·m − 2 ·s − 1 irradiance for three photoperiods, 8, 16, and 24 h under the three composite lights, 88.9% red+ 11.1% blue (R/B), 80.0% red+ 10.0% blue+ 10.0% purple (R/B/P), 72.7% red+ 9.1% blue+ 9.1% purple+ 9.1% green (R/B/P/G), as well as white light (12.7% red+ 3.9% blue+ 83.4% green, W) as control. The results showed that: (1) Plant height, dry weight, rooting rate, average root number, length, surface area and volume, chlorophyll, and chlorophyll fluorescence parameters were significantly affected by photoperiods, light qualities and their interactions. (2) Plantlets subjected to photoperiod 16 h had longer root, higher height, rooting rate, root number, and the higher levels of chlorophyll, chlorophyll a/b, Y (II), qP, NPQ/4 and ETR II compared to photoperiods 8 h and 24 h, while Fv/Fm during photoperiod 16 h was lower than 8 h and 24 h. Plantlets exposed to R/B/P/G generated more root and presented higher chlorophyll, Fv/Fo, Y (II), qP, and ETR II than W during photoperiods 8 and 16 h. (3) Total chlorophyll content and ETR II were significant correlated with rooting rate, root length and root volume, while Fv/Fm and ETR II were significant correlated with plant height, average root number and root surface area. (4) 16-R/B/P/G is best for growing C. lanceolata plantlets in vitro. Conclusions This study demonstrated the effectiveness of photoperiods and light qualities using LEDs for micropropagation of C. lanceolata . The best plantlets were harvested under 16-R/B/P/G treatment. And there was a correlation between the growth and the chlorophyll and chlorophyll fluorescence of their leaves under different photoperiod and light quality. These results can contribute to improve the micropropagation process of this species.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Agriculture / Analysis / Biochemistry and physiology / Biomedical and Life Sciences / Cell division / China / Chlorophyll / Chlorophyll - metabolism / Chlorophyll - radiation effects / Chlorophyll fluorescence / Correlation / Cunninghamia - growth & development / Cunninghamia - metabolism / Cunninghamia - radiation effects / Cunninghamia lanceolata / Design factors / Efficiency / Energy consumption / Flowers & plants / Fluorescence / Growth / In Vitro Techniques / Irradiance / LEDs / Life Sciences / Light / Light emitting diodes / Light emitting diodes (LEDs) / light intensity / Light quality / Lighting / Micropropagation / Photoperiod / Photoperiods / Photosynthesis / Plant growth / plant height / Plant Roots - growth & development / Plant Sciences / Plantlets / Propagation / Quality / Research Article / Rooting / Surface area / Timber / Tree Biology / White light