Effects of Light Intensity on the Growth and Anthocyanin Content of Echeveria agavoides and E. marcus

Abstract

This study was conducted to determine the
effects of light intensity on the growth and development as
well as the anthocyanin content of two Echeveria species,
namely Echeveria agavoides and E. marcus. Three light
intensity levels (high, 150 μmol･m-2s-1; intermediate, 75
μmol･m-2s-1; and low, 35 μmol･m-2s-1) served as the
treatments, which were replicated four times. The results
revealed that the tallest and largest plants were those under
low light conditions. It was observed that there was a
decline as the light intensity increased, which is attributed
to the coping mechanisms of plants to search for light
sources, which has a similar effect to bolting or an increase
in the node-to-node distance. CIELAB color values of L*
and a* for both species were significantly affected by the
light intensity, indicating changes in the lightness of hue and
green-to-red color pigmentation in plants. These results
were strongly reflected in those of the anthocyanin content
analysis, where a direct increase in the concentration was
observed with increasing light intensity. The results of the
anthocyanin analysis were also supported by the
histogram, smart segmentation images, as well as the ratio
of red and green pigments found in the images. Thus, a
high light intensity should be used to increase the quality
and provide conducive growing conditions for both
succulent species.

Full text

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Abstract This study was conducted to determine the
effects of light intensity on the growth and development as
well as the anthocyanin content of two
Echeveria
species,
namely
Echeveria
agavoides
and
E. marcus
. Three light
intensity levels (high, 150 μmol･m
-2
s
-1
; intermediate, 75
μmol･m
-2
s
-1
; and low, 35 μmol･m
-2
s
-1
) served as the
treatments, which were replicated four times. The results
revealed that the tallest and largest plants were those under
low light conditions. It was observed that there was a
decline as the light intensity increased, which is attributed
to the coping mechanisms of plants to search for light
sources, which has a similar effect to bolting or an increase
in the node-to-node distance. CIELAB color values of L*
and a* for both species were significantly affected by the
light intensity, indicating changes in the lightness of hue and
green-to-red color pigmentation in plants. These results
were strongly reflected in those of the anthocyanin content
analysis, where a direct increase in the concentration was
observed with increasing light intensity. The results of the
anthocyanin analysis were also supported by the
histogram, smart segmentation images, as well as the ratio
of red and green pigments found in the images. Thus, a
high light intensity should be used to increase the quality
and provide conducive growing conditions for both
succulent species.
Additional key words: CAM plants, CIELAB, image
analysis, smart segmentation, succulents
Introduction
Common to all plants, photosynthesis has been well studied
for its direct effect on growth, development including essential
physiological processes that translates to yield and quality of
agricultural produce for both horticultural and agronomic crops.
One of the main factors which affects photosynthesis is
light. Its presence, intensity, exposure and quality plays key
roles in the regulation of plant growth, survival and
adaptation (Naoya et al. 2008; Zhang et al. 2003). Several
studies in that deal with light environments and conditions
have been numerous for several horticultural crops as in
hazelnut (Hampson et al. 1996), begonia (Jeong et al.
2009), shrubs (Stanton et al. 2010), tomato (Fan et al. 2013)
and pansy (Koksal et al. 2015) among others. According to
the studies of Jeong et al. (2009) and Vendrame et al.
(2004), the plant form, flowering, leaf size and its color for
herbaceous plant species are affected by light intensity.
Nowadays, the use of artificial light has been considerably
used for horticultural crops due to mass production and quality.
Thus, it has played a remarkable importance among
automation systems in green houses (Koksal et al. 2015).
Studies of Soh et al. (2015) have considered the use of LED
lights for some succulent species. Studies of Nam et al. (2016)
have also studied the effects of intensity but these were various
Crassulaceae species which were grown under hydroponic
systems of which the light was measured in lux values.
However, limited information is available for the effect of its
exposure and more importantly to its intensity. According to
*Corresponding author: Sang Yong Nam
Tel: +82-2-3399-1732
E-mail: namsy@syu.ac.kr
ORCID: htt
p
s://orchid.or
g
/0000-0003-0863-4721
Flower Res. J. (2017) 25(4) : 262-269
DOI htt
p
s://doi.or
g
/10.11623/fr
j
.2017.25.4.11
ISSN 1225-5009(Print)
ISSN 2287-772X
(
Online
)
O R IG IN AL AR T IC LE
Effects of Light Intensity on the Growth and
A
nthocyanin
Content of Echeveria agavoides and E. marcus
Raisa Aone M. Cabahug
1,2
, Son Yil Soh
1,2,
and Sang Yong Nam
1,2,*
1Department of Environmental Horticulture, Sahmyook University, Seoul 01795, Korea
2Natural Science Research Institute, Sahmyook University, Seoul 01795, Korea
Received 10 August 2017; Revised 25 September 2017; Accepted 19 October 2017
Copyright © 2017 by The Korean Society for Floricultural Science

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Flower Res. J. (2017) 25(4) : 262-269 263
Low (2007), indoor plants are often classified on the light
necessary for growth they may be low (35 μmol･m
-2
s
-1
),
medium (75 μmol･m
-2
s
-1
) and high (150 μmol･m
-2
s
-1
).
The popularity and demand of succulents have been
constantly rising due to its drought-tolerant and water-efficient
characteristics. Most of the Crassulaceae species that can be
found in the markets are green in color which have
differentiating rosette formation of its leaves (Nyffeler et al.
2008). Echeveria is considered as one of the popular genus
among the succulent plants. This genus is comprised of 140
species of which 95% of the total is endemic in Mexico (Meyran
and Lopez 2003; Vazquez et al. 2013). Echeveria species are
known for its capability to develop pink to reddish leaf edges
in certain environmental conditions (Fischer and Schaufler
1981). These pigmentation in plants are due to the presence
of anthocyanins (Lo Piero et al. 2005).
The proponents have hypothesized that light intensity is
regulates the development of these pigments in Echeveria
species as well as may affect the growth performance of
these plants which may change its leaf color and structure.
This study aimed to determine the effects of light intensity
on the growth, development and the anthocyanin content
of two succulent Echeveria species.
Materials and Methods
Planting materials
Echeveria agavoides and Echeveria marcus species were
procured from Kim Succulent Nursery, Anseong, South Korea.
These species have a common trait which under unknown
conditions, their leaf margins will turn pinkish to red in color.
Young, healthy and disease-free succulents were chosen as
experimental plants which were around 60-days old and were
placed inside the greenhouse of Sahmyook University, Seoul,
South Korea.
Experimental design, treatments and growth
conditions
The experiment was laid out in a completely randomized
design with four replications with six plants per replication.
There was a total of seventy-two plants per species. Three
light intensity levels served as the factor which were high
(150 μmol･m
-2
s
-1
), mid (75 μmol･m
-2
s
-1
) and low (35 μmol･
m
-2
s
-1
) intensity.
All experimental plants were placed inside three plant
growth chambers (KGC-175 VH, Koenic Ltd., South Korea).
The relative humidity was set at 65%. There was a 14 hours
light period and 10 hours dark period.
Hunter’s CIELAB
Color change was determined using the Hunter’s CIELAB
(Konica Minolta Spectrophotometer CM2600d) which makes
use of the L*a*b* color space to indicate lightness, hue and
saturation of colors. One leaf for each plant was tagged to
trace the color changes. The color value was measured
through two areas within the tagged leaf; margin of the top
and underside of the leaf.
Anthocyanin analysis
Modified quantitative method for anthocyanin (Fuleki and
Francis, 1968) was used in this study by gathering an inch
from the tip of the tagged leaves of succulent plants. One-gram
fresh-cut leaf samples were macerated using a mortar and pestle.
The macerated sample was added with 1 mL of 95% ethanol
and 1.5 N HCl (85 : 15) which served as the extracting solvent.
The mixed solution was transferred to a separate container.
Samples were then centrifuged at 13,000 rpm at 4°C using
the Micro Refrigerated Centrifuge Smart R17 (Hanil Science
Co. Ltd., Seoul, South Korea). This was then stored and
refrigerated overnight. Samples were placed in a microplate
which was then analyzed for a full-spectrum UV/Vis absorbance
at 535 nm using the Fluostar Optima Microplate Reader (BMG
Labtech, Ortenberg, Germany).
Statistical analysis
Data gathering was done every two weeks for a month.
Aside from the Hunter’s CIELAB and anthocyanin analysis,
growth and development parameters were also collected: plant
height and diameter. Statistical analyses were conducted using
Statistical Product and Service Solutions for Windows, version

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264 Flower Res. J. (2017) 25(4) : 262-269
16.0 (SPSS Inc., Japan). The data were analyzed using analysis
of variance (ANOVA), and the differences between the means
were tested using Duncan’s multiple range test (P < 0.05).
Results and Discussion
Plant height and diameter
Results revealed that the use of light intensity levels have
highly affected the growth parameters of both Echeveria
species (Table 1).
The use of high light intensity gave the lowest plant
height for E. agavoides (44.07 mm) ad E. agavoides (47.84
mm). For E. agavoides, the tallest plants were found in
those grown under low light intensity (47.21 mm) and was
followed by mid light intensity (45.29 mm) which were
significantly different from each other. Comparable results
have been observed by those in E. marcus. The tallest
plants were found to be those grown under the low light
intensity (54.29 mm) which significantly did not differ from
those with mid light intensity (54.25 mm).
The plant diameter for both plant species have had the
same growth patterns in their height. Results showed that
diameter of plants for E. agavoides had higher values for
those under low light levels with 94.06 mm which did not
significantly differ from those grown in mid light intensity
with 89.35 mm. The shortest plants were observed from
those treated with high light intensities with 81.59 mm. For
E. marcus, the largest plants were recorded from those in
low light levels as well with 72.48 mm followed by mid
and high with 67.40 mm and 68.90 mm, respectively,
which did not significantly differ from each other.
This result is fairy different from the actual photosynthesis
theory wherein the higher exposure to light would provide
a higher growth rate compared to lower light exposures (Adams
and Early 2004). Long et al. (1994) have also reported that
plants grown under low light grown plants shown to be more
usually susceptible to photo inhibition compared to plants
grown under high light intensities.
However, results of the studies of Steinger et al. (2003)
and Zhang et al. (2003) also reported that low light levels
may lead the plants to increase in height and specific leaf
area (SLA) in order to adjust to various light conditions
which may change morphological and physiological aspects
including the leaf and stem organs. Studies of grasses
regarding shading and their growth rate revealed that it has
a facilitative effect increasing plasticity and has been
considered as an adaptive response which is responsible for
the widespread ability to decouple growth from source of
availability (Semchenko et al. 2012).
Hunter’s CIELAB
Table 2 shows the CIIELAB values of E. agavoides in
response to light intensities. Results shows that the use of
high intensity levels for L* value had the deeper lightness
with 38.96. This was followed by mid intensity level
(40.43) and low intensity level (43.54) for the top portion
of the leaves. This trend was also seen to be similar to
those of the bottom portion of the leaves.
For a* values, positive values indicate that the color is
more inclined to red hues, however negative values tend to
show green colors. Based on the above results on the a*
values for the top portion of the leaves, high intensities had
T
able 1. Average plant height and diameter (mm) of Echeveria species in response to light intensity.
Light intensity
levels
Echeveria agavoides Echeveria marcus
Height Diameter Height Diameter
High 44.07 c
z
81.59 b 47.84 b 68.90 b
Mid 45.29 b 89.35 a 54.25 a 67.40 b
Low 47.21 a 94.06 a 54.29 a 72.48 a
F-test
y
** ** ** **
z
Mean separation within columns by Duncan’s multiple range test at P = 0.05.
y
NS, *, **, Nonsignificant, significant, highly significant at P = 0.05 and P= 0.01, respectively.

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Flower Res. J. (2017) 25(4) : 262-269 265
given -1.03 which is much closer to the positive values
compared to mid and low intensities which had -2.85 and
-4.26, respectively, which did not significantly differ from
each other. This trend was also observed in the bottom
portion of the leaves which had more positive values. On
the other hand, b* values were not significantly affected by
the treatments.
Results for the CIELAB color values for E. marcus is
shown on Table 3 and had been found to have affected L*
and a* values alone.
Results showed that the use of high intensity of light
gave the deepest color hue with an L* value of 43.04 which
was followed by mid (47.77) and low (50.69) light intensity
levels, respectively. This was consistent for the top and
bottom portions of the leaves. Likewise, a* values had a
lower negative value indicating a hue closer to red for
those succulents grown under high light intensity and was
followed by mid and low intensity levels.
Anthocyanin analysis
The average anthocyanin content analysis showed that
Echeveria species were significantly affected using different
light intensities (Table 4).
High light intensity gave the highest value of 0.93 and
0.31 for E. agavoides and E. marcus, respectively. These
were significantly different from those of mid light intensity
which gave 0.55 (E. agavoides) and 0.25 (E. marcus), and
was followed by those of low light intensities 0.28 (E.
T
able 2. Average Hunter’s CILEAB values of E. agavoides in response to light intensity.
Light intensity
levels
Top Bottom
L* a* b* L* a* b*
High 38.96 c
z
-1.03 a 10.36 38.88 b 4.18 a 10.96
Mid 40.43 b -2.85 b 8.88 38.95 b 0.76 b 10.48
Low 43.54 a -4.26 b 10.21 40.02 a 0.38 b 10.01
F-test
y
** ** ns ** * ns
z
Mean separation within columns by Duncan’s multiple range test at P = 0.05.
y
NS, *, **, Nonsignificant, significant, highly significant at P = 0.05 and P = 0.01, respectively.
T
able 3. Average Hunter’s CILEAB values of E. marcus in response to light intensity.
Light intensity
levels
Top Bottom
L* a* b* L* a* b*
High 43.04 c
z
-1.78 b -1.78 48.17 b -2.99 b 18.03
Mid 47.77 b -3.35 a -3.35 49.04 a -3.12 a 17.77
Low 50.69 a -4.26 a -4.26 49.54 a -3.85 a 16.61
F-test
y
* * ns * * ns
z
Mean separation within columns by Duncan’s multiple range test at P = 0.05.
y
NS, *, **, Nonsignificant, significant, highly significant at P = 0.05 and P = 0.01, respectively.
T
able 4. Average anthocyanin content of Echeveria species in response to light intensity.
Light intensity levels Echeveria agavoides Echeveria marcus
High 0.93 a
z
0.31 a
Mid 0.55 b 0.25 b
Low 0.28 c 0.12 c
F-test
y
** **
z
Mean separation within columns by Duncan’s multiple range test at P = 0.05.
y
NS, *, **, Nonsignificant, significant, highly significant at P= 0.05 and P= 0.01, respectively.

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266 Flower Res. J. (2017) 25(4) : 262-269
agavoides) and 0.12 (E. marcus).
According to studies of Rabino and Mancinelli (1986), light
can affect the production of anthocyanin in plants. There is
light-dependent anthocyanin production which occurs in the
plant that displays high irradiance reaction resulting to
photomorphogenic responses. Studies of Beckwith et al.
(2004) also had the same results for Pennisetum setaceum,
a purple pigmented ornamental grass which was when treated
to low-light environments appeared light purple or green
colors which resulted to lower aesthetic appeal.
Image analysis
Smart segmentation of images coupled with the original
images for light intensities and their corresponding histogram
results is presented on Fig. 1 for E. agavoides and Fig. 2
for E. marcus.
Based on the results of the smart segmentation (Table 5),
it was observed that the use of high intensity had more
pixels of red compared to mid and low intensities for E.
agavoides. However, for E. marcus, succulents grown
under mid and low intensities were not significantly
different from each other and had more or less no red
Light intensity Segmented image Histogram
High light intensity
Mid light intensity
Low light intensity
Fig. 1. Original image, processed segmentation image and histogram determining area ratio of green and red pigments of E. agavoide
s
in response to light intensity.

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Flower Res. J. (2017) 25(4) : 262-269 267
Light intensity Segmented image Histogram
High light intensity
Mid light intensity
Low light intensity
Fig. 2. Original image, processed segmentation image and histogram determining area ratio of green and red pigments of E. marcus.
in response to light intensity.
T
able 5. Red and green pigment ratio using smart segmentation in response to different light intensities of Echeveria species.
Light intensity Green pixels Red pixels Total % Green % Red
E. agavoides
High 406.38 (±1.09)
z
973.35 (±5.33) 379.73 29.45 c
z
70.55 a
y
Mid 1422.73 (±3.31) 1581.50 (±1.15) 3004.23 47.36 b 52.64 b
Low 7790.75 (±1.12) 11.35 (±8.30) 7802.09 99.85 a 0.15 c
E. marcus
High 289.41 (±9.13) 7799.88 (±8.10) 8089.29 3.58 b 96.42 a
Mid 3561.95 (±5.96) 65.71 (±4.60) 3627.66 98.19 a 1.81 b
Low 10843.92 (±1.16) 0.00 (±0.00) 10843.92 100.00 a 0.00 b
z
Mean ± standard deviation.
y
Mean separation within columns by Duncan’s multiple range test at P= 0.05.

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268 Flower Res. J. (2017) 25(4) : 262-269
pixels found in smart segmentation. This result is also
consistent with their histogram of images.
Increased red pigments or anthocyanin in higher light
intensity may be due to one of its function as a protective
shield to plants which is exposed to UV light such as
Cotinus coggygria (Shamir and Nissim 1997). These red
pigmentations contribute an important factor in increasing
its increase in marketability and consumer preference
(Shvarts et al. 1997).
Acknowledgement
Succulents Export Innovation Model Development towards
Chinese Market (514006-03-1-HD040)’, Ministry of Agriculture,
Food and Rural Affair and Sahmyook University Research
Fund.
References
Adams CR, Early MP (2004) Principle of horticulture. 4th ed,
Elsevier Butterworth-Heinemann, Burlington, MA
Beckwith AG, Zhang Y, Seeram NP, Cameron AC, Nair MG
(2004) Relationship of light quantity and anthocyanin
production in Pennisetum setaceum Cvs. rubrum and red
riding hood. J Agric Food Chem 52:456-461 DOI:
10.1021/jf034821+
Fan XX, Xu ZG, Liu XY, Tang CM, Wang LW, Han XI (2013)
Effects of light intensity on the growth and leaf
development of young tomato plants grown under a
combination of red and blue light. Scientia Hort 153:50-55
DOI: 10.1016/j.scienta.2013.01.017
Fuleki T and Francis FJ (1968) Quantitative methods for
anthocyanins. Food Science 33:72-77 DOI: 10.1111/
j.1365-2621.1968.tb00887.x
Fischer CC, Schaufler EF (1981) Artificial lighting for decorative
plants. http://www.gardening.cornell.edu/houseplants/pdf/
artificiallighting/pdf
Hampson CR, Azarenko AN, Potter JR (1996) Photosynthetic
rate, flowering, and yield component alteration in hazelnut
in response to different light environments. J Amer Soc
Hort Sci 121:1103-1111
Jeong KY, Pasian CC, McMahon M, Tay D (2009) Growth
of six begonia species under shading. The Open Hort J
2:22-28
Koksal N, Incesu M, Teke A (2015) Supplemental LED
lightning increases pansy growth. Horticultura Brasileira
33:428-433 DOI: 10.1590/S0102-053620150000400004
Long SP, Humphries S, Falkowski PG (1994) Photoinhibition
of photosynthesis in nature. Ann Review of Plant Physiol
Plant Mol Biol 45:633-662 DOI: 10.1146/annurev. pp.45.
060194.003221
Lo Piero AR, Puglisi I, Rapisarda P, Petrone G (2005)
Anthocyanins accumulation and related gene expression
in red orange fruit induced by low temperature storage.
J Agr Food and Chem 53:9083-9088 DOI: 10.1021/
jf051609s
Meyran J, Lopez L (2003) Las Crasuláceas de México.
Sociedad Mexicana de Cactología, A. C. Mexico, D. F.,
pp 2-34
Nam SY, Lee HS, Soh SY, Cabahug RA (2016) Effects of
supplementary lighting intensity and duration on
hydroponically grown Crassulaceae species. Flower Res
J 24:1-9 DOI: 10.11623/frj.2016.24.1.1
Naoya, F, Mitsuko F, Yoshitaka O, Sadanori S, Shigeo N,
Hiroshi E (2008) Directional blue light irradiation triggers
epidermal cell elongation of abaxial side resulting in
inhibition of leaf epinastyin geranium under red light
condition. J Sci Horti 115:176–182
Nyffeler R, Eggli U, Ogburn M, Edwards E (2008) Variations
on a theme: repeated evaluation of succulent life forms
in the Portulacineae (Caryophyllales). Haseltonia J
14:26-36
Rabino I, Mancinelli AL (1986) Light, temperature and
anthocyain production. Plant Physiol 81:922-924 DOI:
10.1104/pp.81.3.922
Semchenko M, Lepik M, Gotzenberger L, Zobel K (2012)
Positive effect of shade on plant growth: amelioration of
stress or active regulation of growth rate? J Ecology
100:459-466 DOI: 10.1111/j.1365-2745.2011. 01936.x
Shamir OM, Nissim AL (1997) UV-light effect on the leaf
pigmentation of Cotinus coggygria ‘Royal Purple’. Sci Hort
71:59-66
Shvarts M, Borochov A, Weiss D (1997) Low temperature
enhances petunia flower pigmentation and induces
chalcone synthase gene expression. Physiol Plant
99:67-72
Soh SY, Park SY, Cabahug RA, Nam SY (2015) Analysis of
supplemental lighting lamps and color on growth of
succulent plants. J Natural Science 19:47-58
Steinger T, Roy BA, Stanton ML (2003) Evolution in stressful
environments II: adaptive value and costs of plasticity in
response to low light in Sinapis arvensis. J Evol Biol
16:313-323
Vazquez JA, Jimeno SD, Cuevas GR, Chazaro BM,
Muñiz-Castro MA (2013) Echeveria yalmanantlanensis

www.ijfs.org
Flower Res. J. (2017) 25(4) : 262-269 269
(Crassulaceae): A new species from Cerro Grande, Sierra
de Manantlán, western Mexico. Brittonia 65: 273–279
DOI: 10.1007/s12228-012-9274-9
Vendrame WV, Moore KK, Broschat TK (2004) Interaction of
light intensity and controlled release fertilization rate on
growth and flowering of two new guinea impatiens
cultivars. Hort Technol 14:491-495
Zhang S, Ma K, Chen L (2003) Response of photosynthetic
plasticity of Paeonia suffruticosa to changed light
environments. Environ Expt Bot 49:121-133