Hydroponics Culture of Edible Opuntia ‘Maya’: Effect of Constant Red and Blue Lights on Daughter Cladodes Growth and Spine Development

Original Paper Environ. Control Biol., 54 (4), 165169, 2016 DOI: 10.2525/ecb.54.165 Hydroponics Culture of Edible Opuntia ‘Maya’: Effect of Constant Red and Blue Lights on Daughter Cladodes Growth and Spine Development

Takanori HORIBE, Yohei IWAGAWA, Hiroki KONDO and Kunio YAMADA

College of Bioscience and Biotechnology, Chubu University, Kasugai, Aichi 4878501, Japan

(Received May 28, 2016; Accepted July 4, 2016)

This study investigates the effects of constant red and blue LED light on the growth and spine occurrence of daughter cladodes in edible Opuntia. Opuntia cladodes were grown by hydroponic culture using the deep flow technique under red, blue, and simultaneous irradiation with red and blue light. Daughter cladodes developed from mother cladodes in all treatments, thus indicating that edible Opuntia can be grown under constant light and hydroponics culture. The speed of elongation growth of first cladodes was lower under blue light than with other treatments. The number of daughter cladodes was also the lowest in cladodes under blue light and was the highest in cladodes under red light. Thus, compared with red light, blue light appears to suppress daughter cladode development. The number of spines, an undesirable characteristic of edible cacti, was the highest on cladodes under simultaneous irradiation with red and blue light. Daughter cladodes under blue light had more spines than those under red light. Our results show that light wavelength strongly affects daughter cladode growth and spine number. Thus, controlling the light environment is important for improving edible cactus growth and quality. Keywords : edible Opuntia, growth, hydroponics culture, LED, light environment, spines

(CAM), a CO2 -concentrating mechanism that potentially INTRODUCTION leads to higher optimal temperatures for photosynthesis (Monson, 1989). CAM plants endure drought by anatomi- The cactus Opuntia (genus Opuntia, subfamily cal modifications, such as thick cuticles and low stomatal

Opuntioideae, family Cactaceae), commonly called nopal frequency together with night-time CO2 uptake (Drennan cactus or prickly pear, is characterized by its remarkable and Nobel, 2000; Pimienta-Barrios et al., 2005), though

adaptation to arid and semi-arid climates. The stems of daughter cladodes show C3 photosynthesis with daytime Opuntia are widely consumed as a vegetable in Mexico, stomatal opening during the early stages of development Latin America, South Africa, and Mediterranean countries (Osmond, 1978; Acevedo et al., 1983) and import water (Stintzing and Carle, 2005; Cruz-Hernandez and Paredes- from mother cladodes (Pimienta-Barrios et al., 2005). López, 2010; El-Mostafa et al., 2014) as well as in Japan, Growth responses of Opuntia plants to temperature and

where they are produced mainly in the Kasugai city, Aichi CO2 concentration are well investigated (Gulmon and

Prefecture. These plants are also used in some countries as Bloom, 1979; North et al., 1995). Elevated CO2 concentra-

remedies for a variety of health problems (El-Mostafa et tions increase the daily net CO2 uptake of cladodes and lead al., 2014). For example, prickly pear is used as a folk to increased biomass production (Cui et al., 1993; Nobel medicine for burns, edema, and indigestion (Shetty et al., and Israel, 1994). Light is essential for plant growth, with 2012). both wavelength and intensity affecting plant growth and Opuntia plants are commonly grown in soil or pot cul- morphogenesis (Mortensen and Stromme, 1987; Yanagi et ture. Major problems commonly encountered in growing al., 2006). Studies have shown that light intensity affects vegetables in soil include soil-borne disease, salt accumula- the elongation growth of Opuntia daughter cladodes and tion, and difficulty in fertilizer management (Lakkireddy et the malate content of cladodes (Littlejohn et al., 1985; al., 2012). In hydroponic culture, plants are grown using North et al., 1995). However, few studies have investi- nutrient solution (water and fertilizer), with or without the gated the relationship between the light environment and use of an artificial medium. Soil-borne disease and weeds growth of edible cacti as far as we searched (North et al., are eliminated in hydroponic culture because there is no 1995). soil and precise fertilizer management is also possible Understanding the relationship between environmental (Lakkireddy et al., 2012). Therefore, hydroponic culture conditions and cladode growth is important for improving provides advantages in the production of edible Opuntia, the production and quality of edible cacti. Here we culti- and we have shown that edible Opuntia can be grown by vated Opuntia using hydroponic culture and investigated simple hydroponics culture (Horibe and Yamada, 2016). the effects of red and blue LED light on its growth. Edible Opuntia exhibit crassulacean acid metabolism

Corresponding author : Takanori Horibe, fax:81926422923, e-mail : [email protected]

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were subjected to analysis of variance, and differences MATERIALS AND METHODS across means were determined using Tukey’s test, with sig- nificance defined as P0.05. Plant materials Edible Opuntia cladodes (Opuntia ‘Maya’) averaging RESULTS 15 cm in length, 7 cm in width, and 1 cm in thickness were harvested at a commercial cactus farm (Goto saboten) in Changes in the length of first daughter cladodes and the Aichi Prefecture, Japan, in July of 2015. Cladodes number of daughter cladodes were transported under dry conditions to our laboratory In all treatments, daughter cladodes developed from within 1 h and were then trimmed to a length of 13 cm. mother cladodes, although the width of daughter cladodes Treatments under red light was slightly less than that of daughter Opuntia cladodes were cultivated using a two-layer cladodes under other treatments (Fig. 2). In all treatments, hydroponic system (Churitsu Electric Co., Japan) in a the first daughter cladodes developed from mother cladodes closed-type plant factory (Fig. 1). OAT House solution A during the first 2 weeks and continued to elongate until har- (OAT Agrio Co., Ltd., Japan), with an electrical conductiv- vesting (Fig. 3A). The speed of elongation was the highest ity of 2 dS m1, was prepared by dissolving 150 g of OAT in cladodes under red light treatment and lowest in those House 1 and 100 g of OAT House 2 in 100 L of water and under blue light treatment. Growth speed was intermediate was used as the hydroponic nutrient solution. Cladodes in cladodes under simultaneous irradiation with red and were transplanted into cultivation panels (88 cm long 57 blue light. The number of daughter cladodes did not sig- cm wide 4 cm high) with a 4.5-cm spacing between the nificantly differ between treatments until 5 weeks. By 6 plants and inter-row spacing of 4 cm and floated on nutrient weeks, the number of daughter cladodes increased in a solution in cultivation beds (90 cm long 60 cm wide 8 cm high). The light sources were red and blue LEDs (Churitsu Electric Co., Japan). Cladodes were then re- tained under constant light as follows: red light, peak emission at 660 nm (red); blue light, peak emission at 440 nm (blue); and simultaneous irradiation with red and blue light (redblue), all at a photosynthetic photon flux density of 180 mol m2 s1. The temperature and relative humidity were maintained at 28°C and 6080%, respectively. The number of daughter cladodes and length of the first daughter cladodes were measured weekly. Daughter cladodes were harvested when they reached a height of 16 cm, and then their weights were measured. We also counted the number of areoles that had spines to calculate the spine occurrence on daughter cladodes as follows: spine occurrence(total number of areoles with spines longer than 1 mm)/(total number of areoles). When a mother cladode had multiple daughter cladodes, the mean spine occurrence was calculated. Fig. 2 Opuntia cladodes 4 weeks after treatment (A, B, and C) and Opuntia daughter cladodes in each treatment (D). Experimental design and statistical analysis Twelve cladodes were used for each treatment (red, blue, and redblue). Ten cladodes from each treatment were used to calculate spine occurrence on daughter cladodes. All experiments were repeated twice. The data

Fig. 3 Length of first Opuntia daughter cladode (A) and number of daughter cladodes (B) in each treatment. Means followed by the same letter within each week did not Fig. 1 Hydroponic culture of edible Opuntia using LED light. differ significantly (P 0.05).

Environ. Control Biol. LIGHT WAVE LENGTH AFFECT THE GROWTH AND SPINE DEVELOPMENT OF EDIBLE OPUNTIA CLADODES

manner similar to that of the length of first daughter cladode (Fig. 3B). The number of daughter cladodes be- DISCUSSION came significantly higher than that of other treatments after 6 weeks, and that of cladodes under blue light became the Hydroponic culture circumvents the expensive and lowest; the number of cladodes under simultaneous irradia- time-consuming task of soil sterilization to prevent soil- tion with red light and blue light became intermediate be- borne disease and enables precise fertilizer management tween the other two treatments. (Wahome et al., 2011; Lakkireddy et al., 2012). In this Average and total fresh weight of daughter cladodes study, we observed that daughter cladodes developed from The average fresh weight (FW) of daughter cladodes mother cladodes under all treatments and continued to grow under blue light and simultaneous irradiation with red and (Fig. 2), indicating that edible Opuntia can be successfully blue light was higher than that of those under red light, with grown by hydroponic culture using the deep flow technique no significant difference between blue and simultaneous ir- (DFT) as we reported before (Horibe and Yamada, 2016). radiation treatments (Fig. 4A). The total FW of mother Our results also suggest that Opuntia cladodes can undergo

cladodes under simultaneous irradiation with red and blue C3 photosynthesis via daytime stomatal opening under con- light became higher than that of those under blue light (Fig. stant light conditions, although it is not clear whether

4B) and did not differ between other treatments. mother cladodes also undergo C3 photosynthesis. In addi- Spine occurrence tion, daughter cladodes in all treatments became relatively Figure 5 shows the occurrence of spines on daughter long and narrow compared with those commonly produced cladodes under each treatment. The number of spines was in the greenhouse (Fig. 2D). Environmental conditions, in- the highest in cladodes under simultaneous irradiation with cluding photoperiod, temperatures, and light wavelength, red and blue light and the lowest in cladodes under red are reported to affect elongation growth of plant stems light. Cladodes under blue light had more spines than those (Shibutani and Kinoshita, 1968; Hidaka et al., 2014). under red light but less than those under simultaneous irra- Cladodes grown by DFT in a green house had shapes simi- diation with red and blue light. lar to those grown in a greenhouse (data not shown). Therefore, the constant light condition might have affected the elongation growth of daughter cladodes, resulting in their slender appearance. Under blue light treatment, the speed of elongation growth of the first daughter cladodes became the slowest and the number of daughter cladodes was the lowest (Fig. 3). Thus, compared with red light, blue light appears to suppress development of daughter cladodes. Growth suppression by blue light has been reported in many plants (Kigel and Cosgrove, 1991; Maas et al., 1995). Blue light suppress hypocotyl growth of Arabidopsis through cryptochrome-mediated signal transduction (Zhao et al., 2007). Zhao et al. (2007) showed that the amount of hypocotyl GA4 decreases after irradiation with blue light, resulting in the suppression of elongation growth. Thus, Fig. 4 Average fresh weight (FW) of Opuntia daughter changes in the concentrations of plant hormones, such as cladodes (A) and total FW of daughter cladodes har- gibberellin, in response to blue light treatment might be in- vested from one mother cladode (B) in each treatment. volved in the observed suppression of growth in daughter Means followed by the same letter within each week did not differ significantly (P0.05). cladodes. The width of daughter cladodes was smallest in those treated with red light (Fig. 2D), resulting in the decrease of average FW of daughter cladodes (Fig. 4A). However, due to the large number of cladodes with red light treatment (Fig. 3B), the total FW of daughter cladodes harvested from one mother cladode did not decrease. The total FW of daughter cladodes was the smallest with blue light treatment because the number of daughter cladodes was less (Fig. 3B). Therefore, red light is more effective than blue light in increasing cladode production. Comparison of spine occurrence on daughter cladodes (Fig. 5) revealed that the number of spines on the cladodes were the highest on those treated with simultaneous irradia- Fig. 5 Spine occurrence in Opuntia daughter cladodes for tion with red and blue light and the lowest on those treated each treatment. Means followed by the same letter within each week did not differ significantly (P with red light alone. These results suggest that blue light 0.05). has a stronger effect on spine development than red light.

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In addition, red and blue light might induce spine develop- ficus-indica) as a source of bioactive compounds for nutrition, ment via different signal transduction pathways as simulta- health and disease. Molecules 19: 1487914901. neous irradiation with red and blue irradiation had the Frego, K. A., Staniforth, R. J. 1985. Factors determining the strongest effect on spine development. Phytochrome and distribution of Opuntia fragilis in the boreal forest of south- eastern Manitoba. Can. J. Bot. 63: 23772382. photropin have been shown to interact with each other Gulmon, S. L., Bloom, A. J. 1979. C3 photosynthesis and high (Devlin and Kay, 2000; Hughes et al., 2012); such interac- temperature acclimation of CAM in Opuntia basilaris engelm. tion might also affect the development of spines on and bigel. Oecologia 38: 217222. cladodes. A number of beneficial functions have been as- Hidaka, K., Okamoto, A., Araki, T., Miyoshi, Y., Dan, K., cribed to spines, including participation in zoochorous dis- Imamura, H., Kitano, M., Sameshima, K., Okimura, M. persal (Frego and Staniforth, 1985; Bobich and Nobel, 2014. Effect of photoperiod of supplemental lighting with 2001), mechanical protection from herbivores (Norman and light-emitting diodeson growth and yield of strawberry. 52 Martin, 1986), shading of the stem (Nobel et al., 1986), fog Environ. Control Biol. :63 71. Horibe, T., Yamada, K. 2016. Hydroponics culture of edible collection (Ju et al., 2012), reflection of light (Loik, 2008), Opuntia ‘Maya’: drought stress affects the development of and decreased water loss (Stintzing and Carle, 2005). spines on daughter cladodes. Environ. Control Biol. 54:153 Thus, environmental factors, such as light intensity, 156. photoperiod, temperature, and humidity, may affect spine Hughes, R. M., Vrana, J. D., Song, J., Tucker, C. L. 2012. development on Opuntia cladodes. Although little is Light-dependent, dark-promoted interaction between known about the relationships between these variables, we Arabidopsis cryptochrome 1 and phytochrome B proteins. J. have shown that light wavelength has a strong effect on Biol. Chem. 287: 22165 22172. Ju, J., Bai, H., Zheng, Y., Zhao, T., Fang, R., Jiang, L. A. 2012. spine development in Opuntia cladodes. The presence of Multi-structural and multi-functional integrated fog collection spines diminishes the appeal of Opuntia to the consumer. system in cactus. Nat. Commun. 3: 1247. Cultivation techniques that decrease the number of spines Kigel, J., Cosgrove, D. J. 1991. Photoinhibition of stem elonga- will increase the commercial value of edible cacti; we think tion by blue and red light: effects on hydraulic and cell wall that control of the light environment will be useful for this properties. Plant Physiol. 95: 10491056. purpose. The effect of light intensity and photoperiod on Lakkireddy, K. K. R., Kasturi, K., Sambasiva, R. K. R. S. 2012. spine development should remain of interest to this indus- Role of hydroponics and aeroponics in soilless culture in com- 1 try. mercial food production. JAST :26 35. Littlejohn, R. O., Ku, M. S. B. 1985. Light and temperature The present study shows that edible cacti can be regulation of early morning crassulacean acid metabolism in grown using DFT and that light wavelength strongly affects Opuntia erinacea var columbiana (Griffiths) L. Benson. Plant the growth and number of spines on daughter cladodes. Physiol. 77: 489491. Manipulating the light environment to promote daughter Loik, M. E. 2008. The effect of cactus spines on light intercep- cladode growth and suppress spine development could im- tion and Photosystem II for three sympatric species of prove the quality and production level of edible cacti. Opuntia from the Mojave Desert. Physiol. Plant. 134:8798. More studies are needed to further understand the relation- Maas, F. M., Bakx, E. J., Morris, D. A. 1995. Photocontrol of stem elongation and dry weight portioning in Phaseolus ship between the light environment and Opuntia develop- vulgaris L. by the blue-light content of photosynthetic photon ment. flux. J. Plant Physiol. 146: 665671. Monson, R. K. 1989. On the evolutionary pathways resulting in

REFERENCES C4 photosynthesis and crassulalacean acid metabolism (CAM). Adv. Ecol. Res. 19:57110. Acevedo, E., Badilla, I., Nobel, P. S. 1983. Water relations, di- Mortensen, L. M., Stromme, E., 1987. Effects of light quality urnal activity changes, and productivity of a cultivated cactus on some greenhouse crops. Sci. Hortic. 33:2736. Opuntia ficus-indica. Plant Physiol. 72: 775780. Nobel, P. S., Geller, G. N., Kee, S. C., Zimmerman, A. D. 1986. Bobich, E. G., Nobel, P. S. 2001. Vegetative reproduction as re- Temperatures and thermal tolerances for cacti exposed to lated to biomechanics, borphology and anatomy of four cholla high-temperatures near the soil surface. Plant Cell Environ. 9 cactus species in the Sonoran Desert. Ann. Bot. 87: 485493. 279287. Cruz-Hernandez, A., Paredes-López, O. 2010. Enhancement of Nobel, P. S., Israel, A. A. 1994. Cladode development, environ- economical value of nopal and its fruits through biotechnol- mental responses of CO2 uptake, and productivity for Opuntia ogy. JPACD 12:110126. ficus-indica under elevated CO2. J. Exp. Bot. 45:295303.

Cui, M., Miller, P. S., Nobel, P. S. 1993. CO2 exchange and Norman, F., Martin, C. E. 1986. Effects of spine removal on growth of the crassulacean acid metabolism plant Opuntia Coryphantha vivipara in central Kansas. Am. Midl. Nat. 116: ficus-indica under elevated CO2, in open-top chambers. Plant 118 124. Physiol. 103: 519524. North, G. B., Lin Moore, T., Nobel, P. S., 1995. Cladode devel- Devlin, P. F., Kay, S. A. 2000. Cryptochromes are required for opment for Opuntia ficus-indica (Cactaceae) under current phytochrome signaling to the circadian clock but not for and doubled CO2 concentrations. AJB 82: 159166. rhythmicity. Plant Cell 12:24992510. Osmond, C. B. 1978. Crassulacean acid metabolism: a curiosity Drennan, P. M., Nobel, P. S. 2000. Responses of CAM species in context. Annu. Rev. Plant Physiol. 29:379414.

to increasing atmospheric CO2 concentration. Plant, Cell Pimienta-Barrios, E., Zañudo-Hernandez, J., Rosas-Espinoza, V. Environ. 23:767781. C., Valenzuela-Tapia, A., Nobel, P. S. 2005. Young El-Mostafa, K., El-Kharrassi, Y., Badreddine, A., Andreoletti, P., daughter cladodes affect CO2 uptake by mother cladodes of Vamecq, J., El-Kebbaj, M. S., Latruffe, N., Lizard, G., Nasser, Opuntia ficus-indica. Ann. Bot. 95: 363369. B., Cherkaoui-Malki, M. 2014. Nopal cactus (Opuntia Shibutani, S., Kinoshita, K. 1968. Studies on the ecolological

Environ. Control Biol. LIGHT WAVE LENGTH AFFECT THE GROWTH AND SPINE DEVELOPMENT OF EDIBLE OPUNTIA CLADODES

adaptation of lettuce. Fac. Agric. Okayama Univ. 32:2534. 7:692698. Shetty, A. A., Rana, M. K., Preetham, S. P. 2012. Cactus: a me- Yanagi, T., Yachi, T., Okuda, N., Okamoto, K. 2006. Light dicinal food. J. Food Sci. Technol. 49: 530536. quality of continuous illuminating at night to induce floral ini- Stintzing, F. C., Carle, R. 2005. Cactus stems (Opuntia spp.): a tiation of Fragaria chiloensis L. CHI-24-1. Sci. Hortic. 109: review on their chemistry, technology, and uses. Mol. Nutr. 309314. Food Res. 49: 175194. Zhao, X., Yu, X., Foo, E., Symons, G. M., Lopez, J., Wahome, P. K., Oseni, T. O., Masarirambi, M. T., Shongwe, V. D. Bendehakkalu, K. T., Xiang, J., Weller, J. L., Liu, X., Reid, J. 2011. Effects of different hydroponics systems and growing B., Lin, C. 2007. A study of gibberellin homeostasis and media on the vegetative growth, yield and cut flower quality cryptochrome-mediated blue light inhibition of hypocotyl of Gypsophila (Gypsophila paniculata L.) World J. Agric. Sci. elongation. Plant Physiol. 145:106118.

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