Growth and cell division of lettuce plants under v

Authors: MyungJin Lee SoYoung Park MyungMin Oh

Publish Date: 2015/05/10

Volume: 56, Issue: 2, Pages: 186-194

PDF Link

Abstract

We investigated the effects of various ratios of red to farred lightemitting diodes LEDs on growth characteristics physiological response and cell division of red leaf lettuce Sixteendayold lettuce seedlings were transferred into growth chambers and cultivated under various ratios of red R and farred FR LEDs R/FR = 07 12 41 and 86 only red LEDs RED or fluorescent lamps control for 22 days Growth characteristics were measured at 11 and 22 days of treatment In addition cell division rate epidermal cell density chlorophyll fluorescence and photosynthesis of leaves were analyzed Fresh and dry weights and leaf area in all R/FR treatments were higher than those in the control at 22 days of treatment The R/FR 12 had the highest values among R/FR treatments The number of leaves appeared to increase as R/FR ratio increased The specific leaf weights in the R/FR ratio of 07 12 and 86 were similar to the control at 22 days of treatment The SPAD values in all R/FR treatments were lower than that in the control All R/FR treatments led to a longer leaf shape than the control The percentage of cells in the G2M phase indicating the cell division rate increased in the R/FR treatments after 4 days of treatment which supported the growth improvement in the R/FR treatments The Fv/Fm and the photosynthetic rate in all treatments decreased due to the absence of blue light The results of this study suggest that the supplementation with farred LEDs should be considered when designing artificial lighting systems for closedtype plant factories since farred light affects the vegetative growth of leafy vegetables such as lettuce

Keywords: