Morphology, biomass and quality variation of Anoectochilus roxburghii under different photoperiods

To explore the effect of different photoperiods on the growth of Anoectochilus roxburghii at different growth period and to provide theoretical basis for determining the suitable photoperiod of A. roxburghii in artificial standardized cultivation. The experiment was carried out in the closed plant factory with 30 days, 60 days and 90 days seedling of A. roxburghii as experimental material. According to the illumination time from short to long, five photoperiods were set up, which were light 10h, light14h, light 16h, light 18h and light 20h, respectively. The growth indexes such as plant height, stem diameter, leaf area, fresh weight, dry weight, flavonoids content and soluble sugar were determined at different growth period. With the extension of the treatment time, the plant height of A. roxburghii in each treatment group increased as a whole. At the later stage of treatment (90 d), the plant height of each treatment increased with the extension of the photoperiod, and the highest value was observed in the light treatment of 20 h. As the treatment time increased, the difference between the different treatments increased. On the 90 days, the stem diameter, leaf area, fresh weight and dry weight all increased first and then decreased with the extension of the photoperiod, and the largest values were observed in the light treatment of 16 h. The flavonoids content and soluble sugar also increased with the treatment time increased for all the light cycle treatment, and the flavonoids content for 14 h and was the higher at 19.13mg/g and 18.05mg/g. Under the 16 h light treatment, the plant height of the 90 day is relatively high, the stem is the thickest, the leaf area is the largest, and the flavonoids content and soluble sugar content are the relatively high. It is the most suitable light period in the vegetative growth period.