Revista Mexicana Ciencias Agrícolas   volume 10   number 8   November 12 - December 31, 2019

DOI: https://doi.org/10.29312/remexca.v10i8.1955

Article

Characterization of chia collections from the western region of Mexico

Lucero Carolina Medina-Santos

Jorge Covarrubias-Prieto

César L. Aguirre-Mancilla

Gabriel Iturriaga

J. Gabriel Ramírez-Pimentel

Juan Carlos Raya-Pérez§

Technological National of Mexico-Technological Institute of Roque. Highway Celaya-Juventino Rosas km 8, Roque, Celaya, Guanajuato, México. CP. 38110. (ncarolinanm@hotmail.com; jor-covarru-jrg@hotmail.com; ceaguirre@itroque.edu.mx; gaiturriaga@itroque.edu.mx: garamirez@itroque.edu.mx).

§Corresponding author: juraya@itroque.edu.mx.

Abstract

Chia is a very valuable resource since it is the main source of unsaturated fatty acids, mainly α-linolenic, in addition to protein and fiber. In this investigation, seven collections were made in seven locations for study and comparison. Seed size were measured, thousand seed weight, volumetric weight, color, germination percentage and oil extraction for chromatography analysis. The collection of cultivated chia from Guanajuato showed greater variability in seed size and that of Roque la minor. The wild collections had the smallest seed size. The cultivated one of Guanajuato has the greater weight in seed and the wild ones the minor, the latter did not germinate, but the domesticated ones did. There were no differences in volumetric weight; however, there were differences in chromatograms (HPLC) and in physical characteristics and color variation in domesticated ones, including white seeds. This prospective research shows that the variability present in wild and cultivated chia can be used for plant breeding.

Keywords: Hirsuta, Salvia hispanica, Salvia tiliifolia, diversity, fatty acid.

Reception date: September 2019

Acceptance date: November 2019

Introduction

Domestication is the result of a selection process that leads plants to a better adaptation to human management, although these adaptations may compromise their survival in nature (Brown 2010). In Mexico, despite being the center of domination of chia (Salvia hispanica), there are few studies of genetic variability; in 2008, a morphological characterization of 22 samples of chia collected in different sites in central and South America was carried out, as well as several states in Mexico including: Sonora, Chihuahua, Jalisco, Morelos and Guerrero (Palma-Rojas et al., 2017).

Wild and domesticated varieties were contemplated, most of these samples had very marked morphological differences. It is known that there are wild populations throughout the country, however, there are no indicators outside their geographical origin that help to differentiate them and the biochemical properties of most of these varieties are unknown. It is possible that by not having this information important productive genotypes are being wasted in the genetic improvement of chia; since variability is essential for sustainability (Brown, 2010).

Chia is a diagnostic species that defines the borders of Mesoamerica (Cahill, 2004), it is an annual crop that is distributed in semi-warm and temperate environments, adapts to clay and sandy soils that are well drained; however, it requires adequate levels of nitrogen to provide good yields (Herman et al., 2016). It is a short-day plant, does not tolerate frost and requires abundant sun to produce; in the first world countries, long-day varieties have been generated and capable of producing in different climatic conditions (Jamboonsri et al., 2012; Grimes et al., 2018). Chia is currently grown in several Latin American countries obtaining yields of up to 3 t ha-1 (Baginsky et al., 2016; Muñoz-Maximo et al., 2017).

In recent decades it has resurfaced, nutraceutical properties and their attractive nutritional benefits have increased their consumption (Xingu et al., 2017). The distribution of this crop grows rapidly, however, there are few sources of information that can provide updated data regarding its production and worldwide distribution (Jamboonsri et al., 2012; Baginsky et al., 2016; Grimes et al., 2018; Win et al., 2018), S. hispanica and S. tiliifolia are the two species that are used for seed production.

The usefulness of the collection and study of genetic resources is exemplified in the tomato or tomato (S. Lycopersicum) in which aspects related to morphology, physiology and yield have been investigated, both of the cultivated species and its wild relatives (Ichihashi and Sinha, 2014). Chia seed contains 32% oil and 20% protein; it contains essential amino acids such as lysine and sulfur amino acids (methionine and cysteine). It has a high antioxidant content (Oliveira-Alves et al., 2017), and has compounds with biological activity in different parts of the plant (Marineli et al., 2015; Fan et al., 2019; Kobus-Cisowska et al., 2019; da Silva, 2015).

Chia is the plant with the highest content of α-linolenic fatty acid, a precursor of eicosapentaenoic and docosahexaenoic fatty acids, important fatty acids for the development of cognition, vision and that reduce the risk of coronary heart disease. The seed also contains 40% of dietary fiber and calcium (Sreedhar et al., 2015; Medina-Santos et al., 2017). The planting location has an effect on the content of α-linolenic, linoeic and oleic and on the omega6/omega3 ratio (Ayerza and Coates, 2009a). The objective of this research was to characterize and compare collections of wild chia (S. tiliifolia and S. hirsutum) and cultivated (S. hispanica) in order to contribute to the knowledge of the diversity of this important plant genetic resource.

Materials and methods

Chia cultivars, spikes in physiological maturity, were made in seven locations: 1) Roque (20° 35’ 00.00’’ north latitude 100° 50’ 11.54’’ west longitude), Celaya, Guanajuato (wild and domesticated); 2) Guanajuato (21° 00’ 02.88’’ north latitude 101° 14’ 24.56’’ west longitude), Guanajuato (domesticated); 3) Ballesteros, Salvatierra (20° 13’ 33.99’’ north latitude 100° 48’ 38.42’’ west longitude), Guanajuato (wild); 4) Comala (19° 19’ 09.09’’ north latitude 103° 46’ 18.08’’ west longitude), Colima (domesticated); 5) Irapuato (20° 16’ 09.61’’ north latitude 10° 13’ 448.31’’ west longitude), Guanajuato (wild and domesticated); 6) Uruapan (19° 26’ 34.09’’ north latitude 10° 20’ 141.01’’ west longitude), Michoacán (wild); 7)

La Calera, Sixto Verduzco (20° 16’ 09.61’’ north latitude 101° 34’ 48.31’’ west longitude), Michoacán (wild). The domesticated ones correspond to the species S. hispanica and that of La Calera and Irapuato to the species S. tiliifolia; that of Salvatierra to the species S. hirsuta. (Calderón de Rzedoswski and Rzedowski, 2004). To obtain the seed, the inflorescences were dried at room temperature and subsequently shaken in order to release the seeds, which were stored in plastic bags with their respective identification at room temperature in a cool and dry place.

To measure the seeds, these were photographed on millimeter paper and subsequently the pixels were quantified by means of the Golden Ratio measurement software, the length and thickness of the seeds in millimeters were calculated by means of the following formula.

To determine the seed weight, three tests were carried out: individual seed weight, weight of 1 000 seeds and volumetric weight. The individual weight was obtained by weighing 50 seeds by means of an analytical balance. For the weight determination of 1000 seeds, 4 repetitions of 200 seeds were performed, weighed and the average was obtained, this average was multiplied by 5 according to the ISTA manual (ISTA, 2005).

The volumetric weight was carried out by weighing the seed that fits in a container of known volume, which was filled by dropping the seed from a funnel from an approximate distance of 5 cm over the central part of the container for a uniform distribution until the container is filled, the excess seed removed by passing a ruler over the edge of it. After obtaining the weight, the conversion to kg hL-1 was performed.

The seed color identification was made by taking samples of 50 seeds from each cultivar that were visually inspected and photographed to know the uniformity of the color, in the cultivars in which more than one seed color was presented, these were counted and determined the percentage of seeds of each color. In order to obtain the germination percentage, three repetitions of 100 seeds were carried out in wet germination paper at a temperature of 25 °C for 8 days in the absence of light, at the end of this period, normal, abnormal and non-germinated seedlings were counted, and an average of the percentage of normal seedlings was obtained (ISTA, 2005).

The modified Folch method (1975) was used for oil extraction; the sample is ground and incubated in a 50:50 (v/v) chloroform-methanol solution under constant stirring at room temperature; the ratio of the solution to the flour for maceration was 4:1 (v/w). After maceration, manual pressing and filtering was done in 8 layers of gauze cloth. The liquid obtained in the filtration was allowed to stand at room temperature for 2-3 days until the solvent mixture was volatized obtaining the oil in the bottle (Puttini et al., 2005). The oil was transesterified in a constant temperature water bath (65- 68 °C), the reaction was carried out by the method proposed by Torossi (2006).

For the analysis, a chromatograph (Thermo Scientific) for HPLC equipped with a C18 hydrophobic column and a UV absorbency detector was used. The fatty acid esters were diluted in HPLC grade methanol (1:1 000) as recommended in the Kromidas HPLC manual (2006), the method used for separation was methanol-water injection with an initial methanol concentration 100% and a final concentration 60% Kromidas (2006) As a comparison commercial chia oil (extracted and made in Jalisco) was used. The data was analyzed using a completely randomized design using the SAS 9.1 program.

Results and discussion

The accessions of cultivated chia evaluated showed highly significant differences in seed size and weight (Table 1), which allows us to assume that they have phenotypic and genotypic differences. The average of the seed length of the Colima collection was 1.95 mm, the Guanajuato had a range of 1.67-2.3 with an average of 2 mm. The Irapuato collection showed values between 1.69 and 3.32 mm. The Guanajuato collection showed greater variability in seed length and Roque’s Chia presented the least variability in this characteristic.

Table 1. Mean squares, degrees of freedom and statistical significance of the analysis of variance of the variable length and weight of seed in chia collections. Celaya, S-S 2016.

**= indicates statistical significance at the 0.01 level of probability.

The wild Chia seed of La Calera presented values between 1.26 and 1.47 mm with an average of 1.36 mm. The seed of the Irapuato collection had an average of 1.35 mm. The seed of the Roque collection presented an average of 1.36 mm. The wild chia of Salvatierra had an average of 1.43 mm. Under natural conditions, the large seed has a higher germination percentage and shows greater vigor, compared to the small ones.

Tenorio-Galindo et al. (2008) point out that the variation in size and color of the seed can be related to germination capacity under different environmental conditions. Jamboonsri et al. (2012), mention that the increase in the size of the part of anthropocentric interest is one of the characteristics of the cultivated plants, in this case the seed of the cultivated forms was twice as large as the wild ones (Table 2).

The cultivated Roque collection had a statistically larger seed size than the rest of the collections; Roque wild seed had the highest absorbency at 4 minutes, the next group regarding this variable was made up of cultivated Roque and wild Calera (Table 2). The wild collections of La Calera, Roque and Irapuato, as expected, had the statistically smaller seed size. Hoyle et al. (2008) found in Goodenia fascicularis, that when they grow in a warm environment, they accelerate the reproductive phase and produce more seed, while those that grow in a fresh environment, accumulate more biomass and produce less seed, but this seed is larger and has more viability.

Table 2. Comparison of means using the Tukey test of the variables individual weight, seed length and absorbency (0.4 minute) of eight chia collections. Celaya, Guanajuato. S-S 2016.

Means with the same letter within each variable are statistically equal (Tukey, p< 0.05).

Ahmed and Fayyaz-ul-Hassan et al. (2015) found that in wheat, water stress increases the protein content in the grain and reduces its size. Ayerza and Coates (2009a) mention that the protein content in chia is influenced by the environment. In wheat, the highest yield is achieved with greater grain weight, which would be worth considering in the selection of chia cultivars (Sun et al., 2017).

The low yields in Chia may be due to the low weight of the seed and the low oil content. Ayerza (2010) mentions that as the altitude decreases the temperature increases and the oil content decreases, although at 1621 meters he found that the ratio ω6-ω3 decreases, which is good for the health of consumers. Celaya is 1750 meters above sea level, very close to the value reported by Ayerza (2010).

C: cultivated; S: wild. In the analysis of variance of the volumetric weight of the samples, no significant difference was found between the cultivars; values of 78.5 (kg hL-1) were found for the Irapuato wild collection and 66.17 (kg hL-1) for the Irapuato cultivated collection. Vázquez-Carrillo et al. (2012) found that in corn the size of the grain did not influence the hectolysis weight, but environmental factors such as precipitation could affect it. Since we worked with wild collections, it could not be ensured if the plants had enough water, as well as domesticated ones, which could explain why there were no differences in this characteristic.

In the Table 3 shows the results of standard germination tests, it can be seen that wild seeds did not show germination; these seeds are dormant because they are wild, since in nature this characteristic is necessary to germinate at different times and when the conditions are optimal to ensure the survival of the species. The seeds of domesticated cultivars showed germination percentages of 78%, relatively low compared to highly domesticated species.

Table 3. Germination percentage of chia, wild and cultivated collections, Celaya S-S 2016.

This result is consistent with Lobo et al. (2007) who point out that the seeds may have morphophysiological latency, with embryos not fully developed and with physiological mechanisms that inhibit germination; the waterproofness of the testa could be what may be preventing germination. Canola studies show that germination depends on the content of fatty acids and other reserves; in corn, a positive correlation was found between lipid content and germination percentage (Seyyedi et al., 2018).

A treatment with gibberellic acid can be applied to wild seeds, since it is capable of inducing germination by helping to break dormancy. With the perception of gibberellins, many enzymes are activated and begin the process of degradation of the endosperm.

Figure 1 shows the representative chromatogram of the domesticated chia of Colima, in which we can observe the appearance of a 0.828 minute peak that does not appear in the commercial oil chromatogram. The highest peak represents α-linolenic acid, however, the percentage of absorbency is greater than the percentage of linolenic acid in commercial chia reported by Gutiérrez (2014). Chia contains between 5 and 16 fatty acids, depending on the growth conditions; the most common are palmitic, stearic, oleic, linoleic and α-linolenic. Ayerza and Coates (2009a) found no differences in four genotypes and reported a linoleic acid content of 20% and α-linolenic acid of 61.7% in the oil composition.

These researchers (2009) reported a selection of chia called Tliltic that has a lower content of linoleic acid (ω6), which could be used to achieve varieties with a good ratio ω3:ω6. The peaks that occur in different cultivars vary in size and are presented or not according to the oil composition of each cultivar. The most outstanding peaks that appear in the three repetitions of each collection were chosen. It is possible to appreciate that in the chromatograms there are three common peaks for all materials; however, the appearance profile of the peaks is different for all collections (Figures 1, 2 and 3). Table 2 shows the percentages of absorbance of the esters of the wild chia oil of La Calera, it can be seen that the percentage of absorbance of the first peak (minute 0.466) is quite high, after this peak, the most visible are those of minute 1.4 and 1.8.

Figure 1. Chromatogram of the oil peaks of chia de Colima (cultivated).

Figure 2. Chromatogram of peaks of oil extracted from chia de la Calera seed (S. tiliifolia, wild).

Figure 3. Chromatogram of the peaks of oil extracted from chia de Salvatierra seed (S. hirsutum).

The general characteristics of chia seeds are presented in Tables 4 and 5 and photographs of some of them are shown (Figures 4 and 5). The great similarity between the seeds of the collections can be observed, all were oval and with smooth pericarp.

Figure 4. Percentage of colors found in chia Silvestre de La Calera, Michoacán.

Figure 5. Percentage of colors found in the cultivated chia seed crop of Colima.

Table 4. Characteristics of wild chia seeds.

Table 5. Characteristics of cultivated chia seeds.

Cahill (2004) located, when studying 348 collections of wild and domesticated chia, greater diversity among wild varieties than among all domesticated ones; points out that there is little cross-linking between wild and domesticated, with differences between them at the level of anthers, calyx and seed morphology. In the varieties of Central America, he did not find gigantism in the seed, with respect to what was found in the Mexican varieties. Jamboonsri et al. (2012) point out that domesticated plants produce large seeds and have no dispersal mechanisms.

Among the wild plants no white seeds were found, up to 1% of white seeds are reported in the cultivated plants. Ayerza (2010) found no differences in the oil content between dark and white seeds, although given that a consumer preference is assumed for white ones, chia selections are already available with this seed color; the white color is governed by a recessive gene, called scc, which would partly explain the absence of seeds of this color in wild collections. In general, the seeds were very similar between the different collections, although they varied in size (Table 4 y 5).

Conclusions

Seeds from wild plant collections are smaller than those produced by cultivated plants. In weight the same thing happens, the seeds of domesticated plants were more than twice as heavy as the seeds of wild plants. The domesticated have white seeds. The wild chia, S. tiliifolia and S. hirsuta show a major peak, approximately 8 to 10 times in greater quantity than the other fatty acids present, which indicates a high content of α-linolenic acid, such as domesticated chia, S. hispanica, shows the peak, but is smaller and statistically different from the wild chia.

Acknowledgments

To Dr. Jesús G. González Gallegos for the identification of the species tiliifolia.

Cited literature

Ahmed, M. and Fayyaz-ul-Hassan. 2015. Response of spring wheat (Triticum aestivum L.) quality traits and yield to sowing date. Plos One 10(4):e0126097.doi:10.137/journal.pone.0126097.

Ayerza, R. 2010. Effects of seed color and growing locations on fatty acid content and composition of two chía (Salvia hispánica L.) genotypes. J. Am. Oil Chem. Soc. 87(10):1161-1165.

Ayerza, R. and Coates, W. 2009a. Some quality components of four chía (Salvia hispanica L.) genotypes agrown under tropical coastal desert ecosystems. Asian J. Plant Sci. 8(4):301-307.

Ayerza, R. and Coates, W. 2009b. Influence of environment on growing period and yield, protein, oil and α-linolenic content of three chía (Salvia hispanica L.) selections. Industrial Crop Products. 30(2):321-324.

Baginsky, C.; Arenas, J.; Escobar, H.; Garrido, M.; Valero, N.; Tello, D.; Pizarro, L.; Valenzuela, A.; Morale, L. and Silva, H. 2016. Growth and yield of chía (Salvia hispanica L.) in the Mediterranean and desert climates of Chile. Chilean J. Agric. Res. 76(3):255-264.

Brown, A. H. D. 2010. Variation under domestication: 1859 and today. Phil. Trans. R. Soc. B. 365:2523-2530.

Cahill, J. 2004. Genetic diversity among varieties of chía (Salvia hispanica L.). Gen. Res. Crop Evol. 51(7):773-781.

Calderon de Rzedowski, G. y Rzedowski, J. 2004. Manual de malezas de la región de Salvatierra, Guanajuato. Flora del Bajío y regiones adyacentes XX. Instituto de Ecología, Xalapa, Ver.  316 p. 

da Silva, R., 2015. Antioxidant potential of dietary chía seed and oil (Salvia hispanica L.) in diet-induced obese rats. Food Res. Intern. 76(3):666-674.

Fan, M.; Luo, D.; Peng, L.; Li, X.; Wu, X.; Ji, X. and Zhao, Q. 2019. Phytochemistry Neo-clerodane diterpenoids from aerial parts of Salvia hispanica L. and their cardioprotective effects. Phytochemistry.166:1-11. doi: 10.1016/j.phytochem.2019.112065.

Folch, J.; Lees, M. and Stanley, G. H. 1957. A simple method for the isolation and purification of total lipids from animal tissues. J. Biol. Chem. 226:497-509.

Grimes, S. J.; Phillips, T. D.; Hahn, V., Capezzone; F., & Graeff-Hönninger; S. 2018. Growth, Yield Performance and Quality Parameters of Three Early Flowering Chia (Salvia Hispanica L.) Genotypes Cultivated in Southwestern Germany. Agriculture. 8(10):154-173.

Gutiérrez, T. R.; Ramírez, V. M. L.; Vega-León, S.; Fontecha, J.; Rodríguez, L. M. y Escobar, M. A. 2014. Contenido de ácidos grasos en semillas de chía (Salvia hispanica L.) cultivadas en 4 estados de México. Rev. Cubana de Plantas Medicinales. 19(3):199-207.

Herman, S.; Marco, G.; Cecilia, B.; Alfonso, V.; Luis, M.; Cristián, V. y Sebastián, A. 2016. Effect of water availability on growth, water use efficiency and omega 3 (ALA) content in two phenotypes of chía (Salvia hispanica L.) established in the arid Mediterranean zone of Chile. Agricultural Water Management. 173:67-75. Doi:10.1016/j.agwat.2016.04.028.

Hoyle, G. L.; Steadman K. J.; Daws M. I. and Adkins S. W. 2008. Pre- and postharvest influences on seed dormancy status of an Australian goodeniaceae species, Goodenia fascicularis. Annals Bot. 102(1):93-101.

Ichihashi, Y.; Sinha, N. R. 2014. From genome to phenome and back in tomato. Curr. Opinion Plant Biol. 18:9-15.

ISTA. 2005. International Seed Testing Association. International Rules for Seed Testing. Zurich, Switzerland. 243 p.

Jamboonsri, W. 2012. Extending the range of an ancient crop, Salvia hispánica L. Genetic Res. Crop Evol. 171-178 pp.

Kobus-Cisowska, J.; Szymanowska, D.; Maciejewska, P.; Kmiecik, D.; Gramza-Michałowska, A.; Kulczyński, B. and Cielecka-Piontek, J. 2019. In vitro screening for acetylcholinesterase and butyrylcholinesterase inhibition and antimicrobial activity of chía seeds (Salvia hispanica). Elec. J. Biotechnol. 37:1-10. Doi: 10.1016/j.ejbt.2018.10.002.

Kromidas, S. 2006. HPLC made to measure: a practical handbook for optimization. Wiley-VCH, 2006. 754 p.

Lobo, M.; Delgado, O.; Cartagena, J. R.; Fernández, E. y Medina, C. I. 2007. Categorización de la germinación y la latencia en semillas de chirimoya (Annona cherimola L.) y guanábana (Annona muricata L.) como apoyo a programas de conservación de germoplasma. Agron. Colomb. 25(2):231-244.

Marineli, R. da S.; Moura, C. S.; Moraes, É. A.; Lenquiste, S. A.; Lollo, P. C. B.; Morato, P. N. and Maróstica, M. R. 2015. Chía (Salvia hispanica L.) enhances HSP, PGC-1α expressions and improves glucose tolerance in diet-induced obese rats. Nutrition. 31(5):740-748.

Medina-Santos, C. L.; Covarrubias-Prieto, J.; Aguirre-Mancilla, C. L.; Iturriaga, G.; Ramírez-Pimentel, J. G. y Raya-Pérez J. C. 2017. Evaluación de algunos compuestos nutraceúticos de la harina de chía. Ciencia y Tecnología Agropecuaria de México. 5(1):12-18.

Muñoz-Máximo, T.; Ocampo-Fletes, I.; Parra-Inzunza, F.; Cervantes-Vargas, J.; Argumedo-Macías, A. and Cruz-Ramírez, S. 2017. Proceso de producción y mecanismos de comercialización de chía (Salvia hispánica L.) por familias campesinas de los municipios de Atzitzihuacán y Tochimilco, Puebla, México. Nova Scientia. 9(19):788-818. doi: 10.21640/ns.v9i19.1104.

Palma-Rojas, C.; González, C.; Carrasco, B.; Silva, H.; & Silva-Robledo, H. 2017. Genetic, cytological and molecular characterization of chía (Salvia hispanica L.) provenances. Bio. System. Ecol. 73:16-21. doi.: 10.1016/j.bse.2017.05.003.

Puttini M.; Vuarant, C. M.; Fournier J.; Lesa, C.; Huter, C.; Ruíz-Díaz, J.; Romero, A. 2005. Determinación de ácidos oleico y linoleico del suero sanguíneo humano por HPLC de fase inversa. Ciencia, Docencia y Tecnología 16(30):179-192.

Seyyedi, S. M.; Tavakkol Afshari, R.; and Daneshmandi, M. S. 2018. The relationships between fatty acids and heterotrophic seedling growth in winter canola cultivars during accelerated seed aging process. South Afr. J. Bot. 119:353–361. Doi: 10.1016/j.sajb.2018.09.034.

Sreeedhar, R V.; Kumari; P. S. D. Rupwate; R. Rajasekharan; M. Srinivasan. 2015. Exploring triacylglycerol biosynthetic pathway in developing seeds of chía (Salvia hispanica L.): a transcriptomic approach. Plos One 10(4):e0123580.doi:10.1371/journal.pone.0123580.

Sun, Y.; X. Yan, S.; Zhang, N. and Wang. 2017. Grain yield and associated photosynthesis characteristics during dryland winter wheat cultivar replacement since 1940 on the Loess Plateau as affected by seedling rate. Emyrates J. Food Agric. 29(1):51-58.

Tenorio-Galindo, G.; Rodríguez-Trejo, D. A.; López-Ríos, G. 2008. Efecto del tamaño y color de la semilla en la germinación de Cecropia dotusifolia Bertol (Cecropiaceae). Agrociencia. 42(5):585-593.

Torossi, F. D. 2006. Reacciones en contexto: la transesterificación en la producción de biodiesel a partir de aceite de fritura usado. Anales de la Real Sociedad Española de Química. 102(3):43-49.

Vázquez-Carrillo, M. G.; Santiago-Ramos, D.; Salinas-Moreno, Y.; Rosas-Martínez, I.; Arellano-Vázquez, J. L.; Velázquez-Cardelas, G. A. y Espinoza-Calderón, A. 2012. Interacción genotipo-ambiente del rendimiento y calidad de grano y tortilla de híbridos de maíz en valles altos de Tlaxcala, México. Rev. Fitotec. Mex. 35(3):229-37.

Win, A. N.; Xue, Y.; Chen, B.; Liao, F.; Chen, F.; Yin, N. and Chai, Y. 2018. Chía (Salvia hispanica) experiment at a 30˚ N site in Sichuan Basin, China. Ciencia Rural. 48(9):1-12.

Xingú-López, A.; González-Huerta, A.; de la Cruz-Torres, E.; Sangerman-Jarquin, D. M., Orozco-de Rosas, G. y Rubí-Arriaga, M. 2017. Chía (Salvia hispánica L.) situación actual y tendencias futuras. Rev. Mex. Cienc. Agríc. 8(7):1619-1631.