Impaginato 235 Adv. Hort. Sci., 2019 33(2): 235-243 DOI: 10.13128/ahs-22792 Impact of light quality on the physiological characteristics of Capsicum chinense seeds D.C. Fontana 1 (*), C.E. Becker 2, M.V.M. Pinheiro 2, M.M. Pretto 2, J. dos Santos 2, B.O. Caron 2, D. Schmidt 2 1 Top School in Agriculture Luiz de Queiroz, University of São Paulo, Piracicaba, SP, Brazil. 2 Federal University of Santa Maria, Campus of Frederico Westphalen, Departament of Agronomic and Environmental Sciences, Linha Sete de Setembro, BR 386 KM 40, 98400-000, Frederico Westphalen, RS, Brazil. Key words: germination, LEDs bulbs, pepper, vigor. Abstract: The objective of this work was to evaluate the physiological quality of Capsicum chinense seeds submitted to different light spectral qualities. It was used a completely randomized design, in a 4x5 factorial scheme, with four pepper cultivars [BRS moema biquinho yellow (Biq. Yellow), Airetama biquinho red (Biq. Red), Boyra Habanero red (Boyra Hab. Red), BRS Seriema tupã bode red (Tupã Bode Red)] and five light spectral qualities, being blue LEDs (B-LEDs); red LEDs (R- LEDs); blue+red LEDs (BR-LEDs); white LEDs (W-LEDs) and fluorescent lamp (FL) carried out germination and vigor analysis, with four replicates of 50 seeds. For this, the seeds were conditioned inside gerbox® boxes and kept in a growth room. The Biq. Yellow and Boyra Hab. Red peppers showed the highest potential of germination and vigor, respectively, indicating high physiological quality. In general, the light spectral qualities provide differentiated responses in the initial development of the pepper cultivars, being the reduction of the percentage of dead seeds favored by the spectrum BR-LEDs and W-LEDs. The root fresh mass is increased by all lights, except R-LEDs. The fresh mass of the aerial part presents positive results in the FL lamps. Shoot length is favored by the R-LEDs. 1. Introduction Capsicum peppers are closely related to the Brazilian richness culture and are a valuable part of the biodiversity heritage, being cultivated an immense variety, sizes, colors, flavors and pungences (Neitzke et al., 2008). The Brazilian production is around 11,071 tons (Conab, 2015), being the state of São Paulo considered the largest producer. Among the factors that regulate plant production, the light plays an important role because it is an important regulator of growth and devel- opment of the plant, as it regulates morphological characteristics and acts as an energy source in the primary metabolism and in the photosynthetic process (Simlat et al., 2016). The qualitative or quantitative characteris- tics of growth and morphogenesis are influenced by the quality of the supplied light, affecting the plants development, mainly, by photomor- phogenic alterations (Heo et al., 2002; Rezende et al., 2008). (*) Corresponding author: daani_fontana@hotmail.com Citation: FONTANA D.C., BECKER C.E., PINHEIRO M.V.M., PRETTO M.M., DOS SANTOS J., CARON B.O., SCH- MIDT D., 2019 - Impact of light quality on the physiological characteristics of Capsicum chinen- se seeds. - Adv. Hort. Sci., 33(2): 235-243 Copyright: © 2019 Fontana D.C., Becker C.E., Pinheiro M.V.M., Pretto M.M., dos Santos J., Caron B.O., Schmidt D. This is an open access, peer reviewed article published by Firenze University Press (http://www.fupress.net/index.php/ahs/) and distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Competing Interests: The authors declare no competing interests. Received for publication 1 March 2018 Accepted for publication 22 February 2019 AHS Advances in Horticultural Science http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/ Adv. Hort. Sci., 2019 33(2): 235-243 236 In recent years, light-emitting diodes (LED) have been widely used as alternative light source potential for plants (Simlat et al., 2016). Among the advantages of LEDs systems are visible light emission and low heat production for long periods, with a specific wavelength, color and lighting flexibility, reduction of electrical con- sumption and toxic substances, as well as improved lifetime (Carvalho, 2007; Yeh and Chung, 2009). This technology becomes promising for the growth of plants in a controlled environment, such as in tissue culture and also in the supplementation of growth chambers and greenhouses (Yeh and Chung, 2009). Different wavelengths of light can trigger a variety of responses in plants (Simlat et al., 2016). For exam- ple, red, blue, green and white LEDs lights were test- ed in different species, mainly forest ones, demon- strating the promotion of seed germination and sub- s eq u en t d ev el o p m en t ( G o n ç a l v es et a l . , 2 0 0 6 ; Victório and Lage, 2009). Red light may promote seed germination and root development (Daud et al., 2013), shoot elongation (Kim et al., 2004; Araújo et al., 2009), fresh mass increment (Sorgato et al., 2016), and an increase in shoot length (Cybularz- Urban et al., 2007), among others. Combinations of blue and red LEDs may promote biomass increase (Gu et al., 2012; Maluta et al., 2013; Da Silva et al., 2016) and increase of the root system (Gu et al., 2012). The blue wavelengths tend to improve stom- atal conductance (Hogewoning et al., 2010), affect phototropism (Johkan et al., 2010), and increase the r a t e o f p h o t o s y n t h e t i c p i g m e n t s p r o d u c t i o n . However, plants exhibit a wide range of morphologi- cal and phytochemical plasticity in response to each type of wavelength of light (Macedo et al., 2011). Many studies report that LEDs can modify seed germination and plant growth and development (Gonçalves et al., 2006; Victório and Lage, 2009; Daud et al., 2013; Da Silva et al., 2016). Although there are reports on the development of seedlings of the genus Capsicum spp. in light qualities (Da Silva et al., 2016), the effects of the light spectral qualities on the germi- nation and vigor of Capsicum chinense have not yet been analyzed. Thus, the objective of this work was to verify the impact of the light spectral qualities on the physiological quality of Capsicum chinense seeds. 2. Materials and Methods Plant material and conduction of the experiment The work was conducted at the Plant Tissue Culture Laboratory of the Universidade Federal de Santa Maria, campus Frederico Westphalen - RS (Federal University of Santa Maria, campus Frederico Westphalen - RS), in november 2016. The experiment was conducted in a completely randomized design, in a 4x5 factorial scheme, with four pepper cultivars (Capsicum chinense) and five light spectral qualities, totaling 20 treatments, with four replicates of 50 seeds each tratament, totalizing 4000 seeds tested. Four cultivars of pepper were used [BRS Moema biquinho yellow (Biq. Yellow), Airetama biquinho red (Biq. Red), Boyra Habanero red (Boyra Hab. Red) and BRS Seriema tupã bode red (Tupã Bode Red)], and five light spectral qualities [TEC-LAMP® blue LEDs - (450 nm) B-LEDs; red LEDs (660 nm) R-LEDs; blue (450 nm) + red (660 nm) BR- LEDs in the ratio of 40% and 60%, respectively; white LEDs W-LEDs; and special daylight type fluorescent FL (Osram®, Brazil)]. The seeds were placed inside gerbox® boxes with l i d s ( 1 1 x 1 1 x 3 c m ) c o n t a i n i n g t w o s h e e t s o f Germitest® paper (in box dimensions), moistened with 0.2% KNO3 solution (dissolved in distilled water), in proportion to 2.5 times the dry paper weight, as described in the Regras Analis de Sementes (Rules for Seed Analysis) (MAPA, 2009). The gerbox boxes were maintained in a growth room under temperature of 25±2°C and a luminous intensity of 36 µmol m-2 s-1 for 14 days. Analyzed variables For the germination test, counting was performed by seven and 14 days after the test installation. At the first count (FC), the normal seedlings were count- ed and the values expressed as a percentage (%), at 14 days the following variables were analyzed: per- centage of germination (PG), percentage of abnormal seedlings (PAS), percentage of hard seed (PHS) and percentage of dead seeds (PDS) (MAPA, 2009). According to MAPA (2009), dead seeds are the seeds that do not germinate at the end of the test, are nei- ther hard nor dormant, and are usually softened, attacked by microorganisms and show no signs of germination. Already, the hard seeds are those that remain without absorbing water for a longer period than normal and are therefore at the end of the test with the appearance of seeds newly placed on the substrate. For the root length (RL) and shoot length (SL) vari- ables, 10 seedlings of each replicate were measured for all light qualities, being measured with a digital caliper. For the fresh mass of the aerial part (FMAP) and root fresh mass (RFM), the same seedlings were Fontana et al. - Light quality impact on Capsicum chinense seeds 237 used for the SL and RL measurement, with the values r e f e r r i n g t o t h e 1 0 s e e d l i n g s . A f t e r w a r d s , t h e seedlings were conditioned in paper bags and kept in a forced air oven at 60°C, until constant weight was reached, to determine the dry mass of shoot (DMS) and dry mass of the root (DMR). The germination speed index (GSI) was calculated by the sum of the number of germinated seeds per day, divided by the number of days between sowing and germination, following the Maguire’s methodol- ogy (1962). GSI= (G1 / N1) + (G2 / N2) + ⋯ + (Gn / Nn) (1) Where GSI = G 1 , G 2 , ..., Gn = number of seedlings computed in the first, second, third and last count; N 1 , N 2 , ..., Nn = number of days of sowing to the first, second, third and last count. The obtained data were submitted to analysis of variance, and the interaction between pepper culti- vars and light spectral qualities was evaluated, and when they were significant, the averages were com- pared by the Tukey’s test, at 5% of error probability, using the statistical program Assistat 7.7 beta. 3. Results The analysis of variance showed significant inter- action for the pepper cultivar factors x light spectral qualities only for the fresh mass of the aerial part (FMAP) and shoot length (SL) variables. The variables of the first count (FC), percentage of germination (PG), normal seeds (NS), abnormal seeds (AS), hard seeds (PHS), germination speed index (GSI), root fresh mass (RFM) and root length (RL) were signifi- cant only for the pepper cultivars factor. Root length (RL), root fresh mass and percentage of dead seeds (PDS) variables were significant for the light spectral qualities factor. On the other hand, the dry mass of the aerial part (DMAP) and dry mass of the root (DMR) variables were not significant (data not shown) by the F test, at 5% of error probability. The pepper cultivars differed for the percentage of normal seeds (NS) and abnormal seeds (AS). The highest percentages of NS were observed for Biq. Yellow pepper with approximately 88%, being the same as Biq. Red pepper (85%), and differing from the others (p<0.05) (Fig. 1A). For the variable AS, the Tupã Bode Red cultivar presented the highest values, with 12.30% of abnormality, being higher than the others, and the lowest percentages were verified for Biq. Yellow pepper, with 4.40% (Fig. 1B). Regarding the percentage of hard seeds, the Boyra Hab. Red cultivar had the highest values, with an aver- age of 11.8%, differing significantly from the others (Fig. 1C). The Biq. Yellow pepper cultivar showed the highest percentages of germination in the evaluation of the first count (FC), with 94.8%, differing signifi- cantly from the Boyra Hab. Red cultivar (Fig. 1D). Fig. 1 - Percentage of normal seeds (NS-A), abnormal seeds (AS- B), hard seeds (HS-C) and germinated (GS-D) of four pep- per cultivars, being Biq. Yellow, Biq. Red, Boyra Hab. Red and Tupã Bode Red, submitted to different light spectral qualities. *Different letters represent significant statisti- cal difference (Tukey’s Test P<0.05; Bars=SD). Adv. Hort. Sci., 2019 33(2): 235-243 238 For the root length variable, the Boyra Hab. pep- per presented the highest values with approximately 51 mm in length, being statistically different from the other cultivars. The lowest averages were observed in Biq. Yellow and Biq. Red peppers with 36 and 35 mm, respectively (Fig. 2A). The Boyra Hab. Red pep- per again stood out for the root fresh mass variable, with 0.072 gram for 10 seedling differing significantly from the other ones evaluated (Fig. 2B). For the germination speed index (GSI), the Biq. Yellow pepper stood out, presenting 23.70, being sig- nificantly similar to the Biq. Red and Tupã Bode Red peppers, differing only from Boyra Hab. Red pepper (Fig. 2C). For the first counting of normal seeds the Biq. Yellow pepper showed the highest values with 84.1% of normal seedlings, differing from the other ones (Fig. 2D). The light spectral qualities of BR-LEDs and W-LEDs provided higher root length (RL), with 43.37 and 42.97 mm respectively, differing statistically from the FL (Fig. 3A). For the root fresh mass variable, it was observed that the red spectrum promoted mass Fig. 2 - Root length (A), root fresh mass (g for 10 seedlings) (B), germination speed index (C) and first counting of normal seeds (D) of four pepper cultivars, being Biq. Yellow, Biq. Red, Boyra Hab. Red and Tupã Bode Red, submitted to different light spectral qualities. *Different letters repre- sent significant statistical difference (Tukey’s Test P<0.05; Bars=SD). Fig. 3 - Root length (A), root fresh mass (g for 10 seedlings) (B) and percentage of dead seeds (C) of four pepper culti- vars submitted to different light spectral qualities, being B - L E D s , R - L E D s , B R - L E D s , W - L E D s a n d F L l a m p s . *Different letters represent significant statistical diffe- rence (Tukey’s Test P<0.05; Bars=SD). Fontana et al. - Light quality impact on Capsicum chinense seeds 239 (Table 1). R-LEDs spectral quality provided the highest aver- ages for the shoot length variable, being higher to the other spectra. In this spectrum, the Boyra Hab. Red and Tupã Bode Red were superior to the other pep- pers. For Biq. Yellow pepper the R-LEDs, FL lamp and BR-LEDs spectra conditioned the larger shoot length, statistically differing from the B-LEDs and W-LEDs. For Biq. red pepper, the R-LEDs spectrum was statistically superior to the others (Table 2). The Boyra Hab. Red pepper presented superior performance to the others, presenting the highest average in shoot lenght (SL), being favored by the LEDs spectra and in disadvantage by the FL, differing significantly. Shoot length of Tupã Bode Red cultivar was favored by the R-LEDs light spectra qualities, dif- fering significantly from the other spectra (Table 2). 4. Discussion and Conclusions The Biq. Yellow pepper cultivar was superior to GSI, FC, NS, PG, presenting the lowest percentage of abnormal (AS) and hard (HS) seeds (Fig. 1). However, the Boyra Hab. Red pepper cultivar has been high- lighted for the RL (Figs. 2A, 3A), SL (Table 2), FMAP (Table 1), RFM (Figs 2B, 3B) variables. The results sug- reduction, with 0.013 gram for 10 seedling, differing statistically from the other light spectra, which pre- sented higher mass (Fig. 3B). Correspondingly, it was observed that the red spectrum conditioned the highest percentage of dead seeds, with 6%, differing statistically from the BR-LEDs and W-LEDs. The BE- LEDs and W-LEDs spectra conditioned low percentage of seed mortality (Fig. 3C). For the Biq. Yellow pepper cultivar the light spec- tral qualities of W-LEDs, FL and BR-LEDs showed the highest values of fresh mass of the aerial part (FMAP), differing significantly from R-LEDs (Table 1). For Biq. Red and Boyra Hab. Red peppers, the FL light provided greater accumulation of fresh mass, pre- senting 0.194 and 0.283 gram for 10 seedlings, respectively, being statistically higher to the others (Table 1). As for the Tupã Bode Red pepper, the W- LEDs light conditioned the largest fresh mass of the aerial part, differing significantly from the B-LEDs and R-LEDs (Table 1). It was observed that the BR-LEDs and FL lights provided a greater increment of fresh mass for Boyra Hab. Red pepper, with 0.236 and 0.283 g for 10 seedling, respectively, differing significantly from the R-LEDs spectrum. The tested peppers presented simi- lar responses in relation to the W-LEDs light spec- trum, not statistically different from each other Table 1 - Fresh mass of the aerial part (g for 10 seedlings) of four pepper cultivars, being Biquinho Yellow, Biq. Red, Boyra Hab. Red and Tupã Bode Red, submitted to different light spectral qualities, B-LEDs, R-LEDs, BR-LEDs, W-LEDs and FL lamps Cultivars Fresh mass of the areal parts B-LEDs R-LEDs BR-LEDs W-LEDs FL Biq. Yellow 0.144 bAB 0.114 bB 0.182 bA 0.191 aA 0.192 bA Biq. Red 0.1233 bC 0.139 abBC 0.179 bAB 0.169 aABC 0.194 bA Boyra Hab. Red 0.196 aBC 0.176 aC 0.236 aAB 0.204 aBC 0.283 aA Tupã Bode Red 0.099 bC 0.138 abBC 0.160 bAB 0.200 aA 0.183 bAB CV 15% * Different lowercase letters in the column or uppercase letters in the row represent significant statistical difference (Tukey’s Test P<0.05). Table 2 - Shoot lenght of four pepper cultivars, being Biquinho Yellow, Biq. Red, Boyra Hab. Red and Tupã Bode Red, submitted to diffe- rent light spectral qualities, being B-LEDs, R-LEDs, BR-LEDs, W-LEDs and FL lamps * Different lowercase letters in the column or uppercase letters in the row represent significant statistical difference (Tukey’s Test P<0.05). Cultivars Shoot lenght (mm) B-LEDs R-LEDs BR-LEDs W-LEDs FL Biq. Yellow 28.66 abB 34.28 bA 30.62 abAB 29.26 bcB 34.15 aA Biq. Red 26.56 bC 37.65 bA 30.34 bBC 30.65 abBC 33.33 aB Boyra Hab. Red 30.74 aB 43.14 aA 34.59 aB 33.92 aB 25.52 bC Tupã Bode Red 29.075 abC 42.10 aA 33.89 abB 26.18 cC 26.53 bC CV 6.71% 240 Adv. Hort. Sci., 2019 33(2): 235-243 gest that Biq. Yellow pepper has a higher germinative potential, while Boyra Hab. Red pepper has greater vigor. The characteristics of germination and vigor are individual for each cultivar and variables between them. For most of them, the speed, uniformity and germination rate depends on external and internal factors to the seed (Plue et al., 2010; Demotes- Mainard et al., 2016), such as temperature, humidity, light, viability of the embryo and genetic factors, characterizing in this way, the differences verified between the pepper cultivars. In general, the use of high vigor seeds results in a good performance of the crops in the field through better establishment of seedlings and survival of seedlings. In this way, ger- mination and vigor tests are important in order to choose the best pepper to be used. Specific light spectra can act positively stimulating the germination process in some species (Gonçalves et al., 2006), or can be indifferent to others. In gener- al, species whose seeds present sensitivity to the light quality, the positive photoblastics, are consid- ered pioneers in nature, since they require light stim- ulus to initiate their germination process (Rebouças and Santos, 2008). For the Capsicum chinense pepper plant, as observed in this study, only the percentage of dead seeds was influenced by the luminous spec- tra tested where the R-LEDs spectrum caused a high number of dead seeds whilst the BR-LEDs and W- LEDs reduced the percentage of mortality. The other germination variables evaluated did not present responses to the spectra. Red light has been reported to stimulate seed germination and root development (Bewley and Black, 1994; Abdullateef and Osman, 2011; Daud et al., 2013). In addition to the quality, the luminous intensity in which the seeds and plants are submitted can also promote differentiated responses in the plant, as ver- ified for Capsicum chinense Habanero, which pre- sented increase in growth with the light intensity of 28 μmol m-2 s-1 (Barrales-López et al., 2015). The luminous spectra used in this experiment were larg- er, with 36 µmol m-2 s-1, which may have masked the plant response. It is known that light in excess can result in reduction of the net photosynthetic rate, causing oxidative damage to the foliar tissues; only under appropriate light plants can be fully self-regu- lated to obtain the best status for absorption and transformation of light energy (Yao et al., 2017). It is known that excess light can also promote photo- voltaic changes in plants, leading to the production of reactive oxygen species (ROS), which may have pro- moted mortality in seeds submitted to the red spec- trum. After germination, it was possible to observe changes in the morphological characteristics due to the different light spectral qualities in which they were submitted. Fluorescent light (FL), for example, provided a higher increase of FMAP in the evaluated peppers. This spectral quality is the most used for in vitro growth of plant species. Positive results in the increase of fresh mass of the aerial part were already found for Curcuma longa in fluorescent light, followed by red light (~ 625-440nm) and yellow light (~565- 590nm) (De Souza Ferrari et al., 2016). Naturally plants develop themselves under varied lights com- posed of a mixture of quality and quantity, which pro- motes the activation of several photoreceptors, among them phytochromes (Rockwell et al., 2006). The highest values of shoot length were verified in R-LEDs spectral quality for Capsicum chinense pep- pers, corroborating with other studies, which found an increase in root formation in cultures such as Jatropha curcas and Protea cynaroides (Daud et al., 2013; Wu and Lin, 2013), and Stevia rebaudiana (Simlat et al., 2016). Kim et al. (2004), observed stretching of the aerial part of chrysanthemums culti- vated in vitro, under light in the red band. When the plants were submitted to the R-LEDs spectrum, some authors verified elongation in Cattleya loddigesii (Araújo et al., 2009), increase of fresh mass in Dendrobium phalaenopsis (Sorgato et al., 2016) and increase of shoot length for Cattleya (Cybularz - Urban et al., 2007), corroborating with the results found in this work. Red light is effective for photosynthesis as the red emission spectrum fits perfectly with the photon energy required to reach the first excited status of a and b chlorophyll (Singh et al., 2015). Lights in blue and red spectra too are strongly absorbed by phy- t o c h r o m e t h r o u g h s p e c i f i c p h o t o r e c e p t o r s (Mathews, 2010). These photoreceptors activate enzymes associated with the synthesis of auxins, growth hormone, and greater photosynthetic effi- ciency (Sun et al., 1998), promoting an increase in growth, justifying the results found. In this way, plants that grow under these conditions have a good initial development, such as a well-formed root sys- tem, which allows for faster acclimation and better survival rates in the field (Chandra et al., 2010; Gruszecki et al., 2010). Positive results for root fresh mass and root length were observed in BR-LEDs spectrum. Some studies indicate that combinations of LEDs with blue (30%) and red (70%) spectrum promoted an increase Fontana et al. - Light quality impact on Capsicum chinense seeds 241 in biomass of Fragaria x ananassa and Saccharum officinarum (Nhut et al., 2003; Maluta et al., 2013). Results for Anthurium andraeanum favored gains in fresh and dry matter in the combination of RB-LEDs, followed by white light (Gu et al., 2012). When RB- LEDs have been used in vitro propagation, a large part of the works observed a mass gain in both the root and the aerial part (Gu et al., 2012; Maluta et al., 2013; Da Silva et al., 2016). For chili culture (Capsicum annuum L. cv. Rubi Gigante), shoot length and collar diameter were favored by treatment with BR-LEDs light compared to white fluorescent light (FL) (Da Silva et al., 2016). For this species, the authors also point out that the dif- ferent qualities of the light spectrum have little effect on the growth and development of seedlings. The photosynthetic pigments absorb light in the red and blue range, the red quality increas the photo- synthetic rate, while blue quality improves the chloroplast development, chlorophyll biosynthesis and stomatal opening, thus, increasing the content of p h o t o s y n t h e t i c p i g m e n t s ( J o h k a n e t a l . , 2 0 1 0 ; Hogewoning et al., 2010; Daud et al., 2013). These luminous spectra influence the primary and sec- ondary metabolism in plant development, however, plants exhibit a wide range of morphological plastici- ty, and phytochemical in response to a given type and wavelength of light (Macedo et al., 2011). In this way, some cultures are favored by the supply of these wavelengths, increasing their growth. The tested peppers showed good results for the root length and root fresh mass variables when sub- mitted to the W-LEDs spectrum. Positive results with the use of W-LEDs were obtained by Wilken et al. (2014), in which they found more vigorous growth of Musa spp. compared to the use of fluorescent lamps. For sugarcane plants, W-LEDs lamps promoted a higher number of shoots, in addition to a higher con- tent of chlorophylls and carotenoids (Ferreira et al., 2017). The emitted photons in the combination of BR- LEDs, suppose that more photoreceptors of the pep- per seedlings received stimuli, which may have trig- gered some morphogenetic mechanism in more pho- toreceptor cells than when exposed to only one spec- trum. Similar assumptions were made by Shimokawa et al. (2014) and Chen et al. (2017). In this way, the positive results found for RFM and RL and the low seed mortality (SM), in the BR-LEDs combination were explained. Light is a signal that is received by photorecep- tors, which regulate plant differentiation and growth (Li et al., 2013). The quality of the emitted light by LEDs has promoted significant improvements in mor- phogenesis and differentiation in different species grown in vitro (Gupta and Jatothu, 2013). However, the effects and mechanisms associated with light quality may be peculiar to each species or cultivar (Li et al., 2013; Da Silva et al., 2016). Some explanations may be generalized, however, this specificity seems to be related to the different responses that were found for the vigor of the pepper cultivars. The Biq. Yellow and Boyra Hab. Red present high potential of germination and vigor, respectively, indi- cating high physiological quality. In general, the light spectral qualities provide dif- ferentiated responses in the initial development of the peppers, being the reduction of the percentage of dead seeds favored by the spectrum BR-LEDs and W-LEDs. The root fresh mass is increased by the all lights, except R-LEDs. The fresh mass of the aerial part presents positive results in the FL lamps. Shoot length is favored by the R-LEDs. Acknowledgements The authors would like to thank the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the scholarship. References ABDULLATEEF R.A., OSMAN M.B., 2011 - Effects of visible light wavelengths on seed germinability in Stevia rebaudiana Bertoni. - Int. J. Biol., 3(4): 83. ARAÚJO A.G., PASQUAL M., RODRIGUES F.A., RODRIGUES J.D., CASTRO E.M., SANTOS A.M., 2009 - Crescimento in vitro de Cattleya loddigesii Lindl. em diferentes espec- tros luminosos associado a ácido giberélico. - Rev. Ceres, 56(5): 542-546. 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