¹Campo Experimental Saltillo. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. México.

²Departamento de Fitomejoramiento, Universidad Autónoma Agraria Antonio Narro. México.

The study of seeds includes tests that allow characterizing and defining the suitability of germplasm to conserve or propagate species. This study aimed to evaluate the effect of different pre-germination treatments on the germination rate of Agave potatorum. A completely randomized design with a 5×3×2 fixed-effect factorial arrangement was utilized; five pre-germination treatments were assessed: T1: 500 ppm gibberellic acid (AG₃); T2: 1 000 ppm AG₃; T3: 50 % inoculation of mycorrhizae (23 spores gram^-1) (Glomus intraradices); T4: 100 % mycorrhizae (46 spores gram^-1) and T5: Control (distilled water), applied in three seed sizes (small, medium and large) and two dates of monitoring: D1=10 and D2=15 days; the assessed variable was germination rate (GR, %). Tukey tests (α=0.05) were applied when statistical differences between factors, levels, and interactions were obtained. The results indicated that germination of A. potatorum differs statistically between dates (p=0.0004) and treatments (p=0.0005), but not between seed sizes (p=0.3335). The application of 500 ppm AG₃ registered a GR of 75 %. This pre-germination treatment speeds germination, improves seedling production, and maximizes the potential of the seed lot. Ex situ conservation is essential to promote sustainable use and revalue the potential of germplasm, both in its ecological and productive functions.

Keywords: Gibberellic acid, Agavoideae, Asparagaceae, germination, Tobalá agave, mycorrhizae.

El estudio de las semillas incluye ensayos que permiten caracterizar y definir la aptitud del germoplasma para conservar o propagar especies. El objetivo de este estudio fue evaluar el efecto de diferentes tratamientos pregerminativos sobre el porcentaje de germinación de Agave potatorum. Se utilizó un diseño completamente al azar con arreglo factorial 5×3×2 de efectos fijos; se evaluaron cinco tratamientos pregerminativos: T1: 500 ppm de ácido giberélico (AG₃); T2: 1 000 ppm de AG₃; T3: 50 % de inoculación de micorriza (23 esporas gramo^-1) (Glomus intraradices); T4: 100 % de micorriza (46 esporas gramo^-1) y T5: Testigo (agua destilada), aplicados en tres tamaños de semilla (chica, mediana y grande) y dos fechas de monitoreo: F1=10 y F2=15 días; la variable evaluada fue la germinación (GE, %). Se aplicaron pruebas de Tukey (α=0.05) cuando se obtuvieron diferencias estadísticas entre factores, niveles e interacciones. Los resultados indicaron que la germinación de A. potatorum es estadísticamente diferente entre fechas (p=0.0004) y tratamientos (p=0.0005), pero no en tamaño de semillas (p=0.3335). La aplicación de 500 ppm de AG₃ registró una GE de 75 %. Este tratamiento pregerminativo hace más rápida la germinación, mejora la producción de plántulas y maximiza el potencial del lote de semilla. La conservación ex situ es fundamental para promover el uso sostenible y revalorizar el potencial del germoplasma, tanto en sus funciones ecológicas como productivas.

Palabras clave: Ácido giberélico, Agavoideae, Asparagaceae, germinación, maguey tobalá, micorriza.

Agave potatorum Zucc. (Verschaffelt agave) belongs to the family Asparagaceae and subfamily Agavoideae (APG, 2016; García-Mendoza et al., 2019); it is distributed from the eastern end of the Balsas River basin, through the Tehuacán-Cuicatlán Valley, to the lower parts of the Mixtec Sierra and central mountains of Oaxaca (García-Mendoza, 2010). It is a non-timber species utilized to produce “Tobalá” mezcal, which has a high market potential (Barrientos et al., 2019).

In Oaxaca, its cultivation is incipient (García et al., 2004) and the acaule or agave heart requires between 8 and 12 years for its utilization (Martínez-Ramírez et al., 2013); it is used before flowering, which interrupts the process of sexual reproduction, limits the production of seeds, which is a source of germplasm for more effective propagation (García-Mendoza, 2010). Asexual reproduction is nonexistent, because it does not produce vegetative propagules (Torres et al., 2015).

According to the International Seed Testing Association, ISTA (ISTA, 2021), standard germination evaluation is the most common procedure to know the physiological quality of a seed lot, this is performed under controlled conditions for seeds to carry out the stages or phases of germination (García-López et al., 2016).

In A. potatorum, germination is epigeous, oleoproteaginous, and recalcitrant (Gutiérrez-Hernández et al., 2020). Ortiz-Hernández et al. (2018) suggest assessing the germination rate 10 and 15 days after sowing (dds).

In other species like Agave lechuguilla Torr., Agave asperrima Jacobi, Agave salmiana Otto ex Salm-Dyck,and Agave striata Zucc., the physiological quality of the seed, the effect of the temperature gradient and water potential (ψ) on germination have been evaluated (Ramírez, 2010). Peña-Valdivia et al. (2006) observed a germination rate of 95 % for A. salmiana, 70 % for A. mapisaga Trel., and 50 % for A. angusifolia Haw. subsp. tequilana (F. A. C. Weber) Valenz.-Zap. & Nabhan (Ramírez et al., 2016).

In germination processes, arbuscular mycorrhizal fungi (AMF) influence the softening of the testa (Quiñones-Aguilar et al., 2016) and the production of phytohormones such as gibberellins and indolacetic acid in the seed (Alcántara et al., 2019). Likewise, AMF form symbiotic associations with plants and influence phosphorus uptake; in agaves, their effect has been evaluated in the growth of Agave inaequidens K. Koch (Quiñones-Aguilar et al., 2016) and Agave cupreata Trel. & A. Berger (Trinidad-Cruz et al., 2017).

Agave potatorum is a strategic phytogenetic resource with economic value inextricably linked to the culture of the communities of San Miguel Piedras, Nochixtlán, Oaxaca, Mexico, where there is a need to promote its sustainability. Within this context, the objective was to assess the effect of different pre-germination treatments on the germination rate, to generate a propagation and multiplication strategy.

Agave potatorum is a perennial, monocarpic plant 30 to 60 cm high and 34 to 60 cm in diameter; it blooms from August to November, fructifies from November to March, and produces seeds only once in its life cycle; it reaches sexual maturity at approximately six years of age; it is acaulescent (does not generate tillers), and its leaves are succulent, ovate, 15 to 35 cm long and 5 to 10 cm wide, whitish to green in color, arranged in a rosette (Gentry, 1982; García-Mendoza, 2010). It is distributed within an altitude range of 1 240 to 2 400 meters above sea level, in association with pine-oak vegetation, low deciduous forest, and xerophilous scrub with Quercus L. It grows on flat or gently sloping sites, on sandy soils derived from limestone rocks (Gentry, 1982; Morales et al., 2017; Gutiérrez-Hernández et al., 2020).

The collection site is located in the ejido Guadalupe Victoria, municipality of San Miguel Piedras, Nochixtlán, Oaxaca, Mexico, between the coordinates 17°01'7.62” N and 97°13'19.27” W, at an altitude of 1 832 m (Calderón de Rzedowski and Germán, 1993); its climate type is semi-warm sub-humid (A)C(w₁) (García et al., 2004), with mean annual temperature of 16.5 °C, average annual precipitation of 842.2 mm; its soil type is Litosol (Inegi, 2018) (Figure 1).

Yutanduchi de Guerrero = Municipality of Yutanduchi de Guerrero; San Juan Tamazola = Municipality of San Juan Tamazola; Santa María Peñoles = Municipality of Santa María Peñoles; San Pedro Teozacoalco = Municipality of San Pedro Teozacoalco; San Antonio Huitepec = Municipality of San Antonio Huitepec; San Francisco Cahuacua = Municipality of San Francisco Cahuacua; San Mateo Yucutindoo = Municipality of San Mateo Yucutindoo.

Figure 1. Location of the study area in the ejido Guadalupe Victoria, municipality of San Miguel Piedras, Nochixtlán, Oaxaca, Mexico.

In February 2021, 80 mature capsules of A. potatorum were collected from adult plants and selected based on their height (cm), diameter (cm), and rosette conformation (Garcia-Mendoza et al., 2019). The fruits were placed in clear, airtight plastic bags (10×10 cm) at room temperature (25 °C).

The seeds were kept for one year under refrigeration at 4 °C and a relative humidity of 5 %; germination tests were carried out in the Plant Tissue Culture laboratories of the Saltillo Experimental Field CIRNE-INIFAP and at the Center for Training and Development in Seed Technology (CCDTS) of the “Antonio Narro” Autonomous Agrarian University (Universidad Autónoma Agraria Antonio Narro).

Pure seeds (310.27 g) were used in the study with a viability of 71 %, determined with the 0.5 % 2,3,5-triphenyl tetrazolium chloride (Sigma-Aldrich^®, USA) test (ISTA, 2021). The pure seed was separated by size with a model CFY-II South Dakota^® blower, with an opening of 3 cm 1 min^-1, to obtain three samples: small (186.15 g), medium (77.56 g), and large (46.56 g) seed according to the classification of Vázquez et al. (2011).

Five treatments were assessed for the three seed sizes (small, medium, and large): T1: 500 ppm gibberellic acid (Sigma-Aldrich^®, USA) (AG₃); T2: 1 000 ppm AG₃(base solution of 100 mg of AG₃ in 100 mL of distilled water); T3: 50 % mycorrhiza inoculation (23 spores g^-1) (Glomus intraradices N. C. Schenck & G. S. Sm. 1982); T4: 100 % mycorrhiza (46 spores g^-1) (base solution 1 g of mycorrhiza in 100 mL of distilled water); and T5: Distilled water (control).

The germination test was carried out based on ISTA (ISTA, 2021) with the modification in the number of seeds in each experimental unit, due to the reduced amount of pure seeds collected. 20 seeds of each size were considered as an experimental unit, and nine repeats per treatment were established. Rao et al. (2007) and Di Sacco et al. (2020) have suggested that, for species with regeneration problems, especially wild taxa, 100 to 300 seeds constitute a good sample size for statistical analysis.

Each experimental unit was placed in a Petri dish on Whatman #1 filter paper, previously soaked with 3 mL of the corresponding treatment. The nine repeats per treatment of the three seed sizes were placed in a model UMF500 Hoffman^® brand incubation chamber at a controlled temperature (28±1 °C), with a photoperiod of 8 h light and 16 h dark (ISTA, 2021).

For each treatment, two evaluation dates were considered: D1=10 dds and D2=15 dds (Ortiz-Hernández et al., 2018). For each seed size, 900 were evaluated for a total of 2 700.

The number of germinated seeds was determined to obtain the standard germination rate (GR) by treatment and seed size, based on the classification of AOSA (1983); germination was the dependent variable. The data were subjected to an analysis corresponding to a completely randomized design with a 5×3×2 factorial arrangement of fixed effects with the following model:

The assumptions of homogeneity of variance (Barlett and Levene for interactions), normality (Shapiro-Wilk), independence (test of spurts) and non-additivity of the model (Tukey) were verified to ensure that they were met. Since the variable is expressed in percentage units, the arcsine transformation was used. When statistical differences existed between factors, levels, and interactions, Tukey tests were applied (α=0.05). For the statistical analysis, the following libraries were used: ‘tidyverse’ and ‘agricolae’ of the R^® statistical software version 3.5.3 (R Core Team, 2020).

There are significant differences in the germination race of A. potatorum between: Dates (p=0.0004), Treatments (p=0.0005); and in the interactions: Date×Treatments (p=0.0011) and Size×Treatments (p=0.0012) (Table 1, Figure 2). A Coefficient of variation of 18.12 % was obtained and the model explained more than 63 % of the variability of germination, resulting in a good model.

Variation source	D. F.	S. S.	M. S.	F value	Pr(>F)	Significance
Date	1	1 359.90	1 359.87	14.32	0.0004	***
Size	2	212.40	106.20	1.12	0.3335
Treatments	4	2 232.00	558.01	5.88	0.0005	***
Date×Size	2	405.60	202.82	2.14	0.1270
Date×Treatments	4	1 978.80	494.71	5.21	0.0011	**
Size×Treatments	8	2 871.90	358.99	3.78	0.0012	**
Date×Size×Treatments	8	742.90	92.86	0.98	0.4620
Residuals	60	5 697.20	94.95

Letters above the bars indicate the groups according to Tukey's test at 95 %. D1 and D2 = Germination evaluation dates at 10 and 15 days after planting; T1 = 500 ppm gibberellic acid (AG₃); T2 = 1 000 ppm gibberellic acid (AG₃); T3 = 50 % Glomus intraradices N. C. Schenck & G. S. Sm. 1982; T4 = 100 % G. intraradices; T5 = Distilled water (control).

Figure 2. Effect of the date, pre-germination treatments, and seed size on germination in Agave potatorum Zucc.

Evaluation dates. The highest germination rate (69.00 %) of A. potatorum was registered at 15 dds (Table 2; Figure 3A). However, it differs from the findings of Ortiz-Hernández et al. (2018), who, under the same germination conditions, estimated a GR of 82 to 85 % with seeds from Coixtlahuaca (Mixteca region) and Zaachila (Central Valleys) of Oaxaca, respectively. The two sites exhibit differences in altitude (2 500 masl and 1 650 masl), precipitation (600 to 700 mm and 800 to 900 mm), and temperature (5 to 25 °C and 10 to 30 °C), with respect to the collection site of the present study, which shows the phenotypic plasticity of the species and the influence of the environment on the germination capacity.

Table 2. Descriptive statistics of germination (%) of Agave potatorum Zucc. in original units.

Factor/level	n	Min.	Max.	Median	I. Q. R.	Mean*	S. D.	S. E.	C. I.	C. V.
Date
D1	2 700	30.00	100.00	60.00	30.00	57.33 a	18.02	2.69	5.41	31.42
D2	2 700	30.00	100.00	70.00	40.00	69.00 b	18.82	2.81	5.65	27.27
Size
Small	900	30.00	100.00	60.00	35.00	59.33 a	19.99	3.65	7.46	33.69
Large	900	30.00	100.00	60.00	30.00	64.00 a	19.23	3.51	7.18	30.04
Medium	900	30.00	90.00	70.00	30.00	66.17 a	18.46	3.37	6.89	27.90
Treatments
T1	540	30.00	100.00	80.00	17.50	75.00 a	19.78	4.66	9.84	26.37
T2	540	30.00	90.00	60.00	27.50	60.56 b	18.30	4.31	9.10	30.22
T3	540	30.00	100.00	60.00	20.00	62.22 ab	19.87	4.68	9.88	31.93
T4	540	40.00	90.00	65.00	30.00	65.00 ab	18.55	4.37	9.23	28.54
T5	540	30.00	90.00	50.00	11.25	53.06 b	14.26	3.36	7.09	26.88

n = Number of observations; Min. = Minimum value; Max. = Maximum value, I. Q. R. = Interquartile range; Mean* = Equal letters indicate that the groups are statistically equal at 95 % according to Tukey's test; S. D. = Standard deviation; S. E. = Standard error; C. I. = Confidence interval of the mean; C. V. = Coefficient of variation (%). D1 and D2 = Germination evaluation dates 10 and 15 days after planting; T1 = 500 ppm gibberellic acid (AG₃); T2 = 1 000 ppm gibberellic acid (AG₃); T3 = 50 % Glomus intraradices N. C. Schenck & G. S. Sm. 1982; T4 = 100 % G. intraradices; T5 = Distilled water (control).

Between: A = Dates×Seed size; B = Date×Treatments; C = Seed size×Treatments. D1 and D2 = Germination rate assessment dates 10 and 15 days after sowing; T1 = 500 ppm gibberellic acid (AG₃); T2 = 1 000 ppm gibberellic acid (AG₃); T3 = 50 % Glomus intraradices N. C. Schenck & G. S. Sm. 1982; T4 = 100 % G. intraradices; T5 = Distilled water (control). The horizontal overlap of the vertical lines (within each figure, A, B, or C) indicates that the means are statistically equal (95 %) according to Tukey's test.

A close relationship between seed size and germination rate has been registered (Vázquez et al., 2011) due to reserve content and embryo size; however, the seed size of A. potatorum did not influence the germination rate (p=0.3335, Table 1).

Effect of treatments. The highest germination rate in A. potatorum (75 %) was obtained with the application of gibberellic acid (AG₃) at 500 ppm (T1); while the rest of the treatments (T2-T5) registered statistically the lowest germination rates (Figure 3B); this is also the case with Agave lechuguilla, A. asperrima, A. salmiana, and A. striata (Ramírez, 2010). The effect of this treatment shows the need to apply a pre-germination treatment to improve germination and optimize the seed lot of A. potatorum.

Ortiz-Hernández et al. (2018) recorded a germination rate of 4 % for the same species without AG₃ application, a result that corroborates the need to assess the physiological quality of the seed and its response to different pre-germination treatments.

Although AG₃ has been documented to enhance germination in some species (Kaya and Kulan, 2020), in A. potatorum, 1 000 ppm AG₃ had an inhibitory effect, similar to that observed in other cultivars (Vásquez et al., 2019), as it affects the synthesis of α-amylases and hydrolytic enzymes (Ho et al., 2003). Although there is no information on the mycorrhizal effect on the germination of this species, the inoculation registered a difference of only 12 % concerning the Control (T5), which exhibited the lowest germination rate (53 %); the application of G. intraradices may influence the mechanical resistance of the testa (Quiñones-Aguilar et al., 2016) and the stimulation of the production of phytohormones such as gibberellins and indoleacetic acid (Alcántara et al., 2019).

Date×Treatment interaction. The Anova showed that treatments recorded different germination rates of A. potatorum between Dates (p=0.0011) (Table 1); only certain interactions were statistically significant (p<0.05, Table 3C, Figure 3B). This is consistent with previous studies (Constantino et al., 2010; Quiñones-Aguilar et al., 2016; Alcántara et al., 2019; Cruz-Cárdenas et al., 2021), as the difference depends on the physiology of each species.

Table 3. Statistically significant Tukey's multiple contrasts of the Agave potatorum Zucc. germination rate.

Contrast	Difference	Lower limit	Upper limit	Adjusted p value	Means*
Date of assessment (A)
D2-D1	7.7742	2.4549	13.0935	0.005	69.00	57.33
Treatments (B)
T5-T1	-15.280	-25.645	-4.915	0.001	53.06	75.00
T2-T1	-10.746	-21.111	-0.381	0.038	60.56	75.00
Date: Treatments (C)
D2:T5-D2:T1	-24.861	-41.955	-7.768	0.000	46.11	83.33
D1:T3-D2:T1	-23.930	-41.023	-6.836	0.001	47.78	83.33
D2:T5-D2:T3	-20.639	-37.733	-3.546	0.007	46.11	76.67
D2:T3-D1:T3	19.708	2.614	36.801	0.012	76.67	47.78
D1:T4-D2:T1	-18.999	-36.093	-1.906	0.018	55.56	83.33
D1:T2-D2:T1	-18.579	-35.673	-1.486	0.022	56.67	83.33
D2:T5-D2:T4	-17.813	-34.907	-0.720	0.034	46.11	74.44
D2:T4-D1:T3	16.881	-0.212	33.975	0.056	74.44	47.78
Seed size: Treatments (D)
T5:Small-T1:Small	-28.251	-51.846	-4.657	0.006	48.33	86.67
T5:Medium-T1:Small	-26.765	-50.360	-3.170	0.012	50.83	86.67
T3:Small-T1:Small	-26.371	-49.965	-2.776	0.015	51.67	86.67
T2:Small-T1:Small	-25.221	-48.816	-1.626	0.025	53.33	86.67
T4:Small-T1:Small	-23.214	-46.809	0.381	0.058	56.67	86.67

D1 and D2 = Germination assessment dates 10 and 15 days after planting; T1 = 500 ppm gibberellic acid (AG₃); T2 = 1 000 ppm gibberellic acid (AG₃); T3 = 50 % Glomus intraradices N. C. Schenck & G. S. Sm. 1982; T4 = 100 % G. intraradices; T5 = Distilled water (control). Means* in original units, respectively corresponding to the variables in column 1.

Size×Treatments interaction. The results of Tukey's mean contrasts showed that the highest germination rate (86.67 %) of A. potatorum occurred with T1, in small seeds (Table 3D, Figure 3C). No statistically significant differences were observed in the germination rate of A. potatorum among the treatments applied to large seeds.

The results indicate that the use of AG₃ significantly improves germination of A. potatorum seeds; however, high doses inhibit the hormonal action of the seeds. The inhibitory effect may also be due to an alteration of other phytohormones such as cytokinins, polyamines, and jasmonic acid, that are also involved in the embryonic and root development during germination (Alcántara et al., 2019).

It has been observed that the large seeds, having a larger and heavier embryo, exhibit a germination capacity that allows them to denature certain proteins, synthesize nutrients, and perform lipid hydrolysis (Baskin and Baskin, 2001; Finch-Savage and Leubner-Metzger, 2006), therefore producing healthy seedlings (Ramírez, 2010).

Applying 500 ppm of gibberellic acid (AG₃) 15 days after sowing is the most effective treatment to improve the germination of A. potatorum seeds; therefore, its use in propagation practices is suggested. A higher dose of AG₃ and the use of mycorrhizae inhibit germination. Small seeds respond better to germination treatments with 500 ppm AG₃, while the size of medium and large seeds does not influence the germination of this species. The results support the ex situ conservation and sustainable utilization of A. potatorum, as they provide a solid basis for future research and propagation practices.

The authors are grateful to the Saltillo Experimental Field of the National Institute for Research on Forestry, Agriculture, and Livestock (Instituto de Investigaciones Forestales, Agrícolas y Pecuarias, INIFAP) for providing the facilities for this work. To the producers of ejido Guadalupe Victoria, in the municipality of San Miguel Piedras, Nochixtlán, and to the Mexican Regulatory Council for the Quality of Mezcal (Consejo Mexicano Regulador de la Calidad del Mezcal, A. C.) of Oaxaca for the facilities granted for obtaining the germplasm.

Eulalia Edith Villavicencio-Gutiérrez: execution, research and analysis supervision, interpretation of results, and drafting of the manuscript; Ma. Alejandra Torres-Tapia: methodological design and revision of the manuscript; Jorge Méndez González: statistical analysis; Carolina Curiel-López: germplasm selection and collection; Félix Sánchez-Pérez: verification and statistical analysis of the results.

Alcántara C., J. S., J. Acero G., J. D. Alcántara C. y R. M. Sánchez M. 2019. Principales reguladores hormonales y sus interacciones en el crecimiento vegetal. NOVA 17(32):109-129. Doi: 10.22490/24629448.3639.

Angiosperm Phylogeny Group IV. 2016. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Botanical Journal of the Linnean Society 181(1):1-20. Doi: 10.1111/boj.12385.

Association of Official Seed Analysts (AOSA). 1983. Seed Vigor Testing Handbook. AOSA. Ithaca, NY, United States of America. 100 p.

Barrientos R., G., E. L. Esparza I., H. R. Segura P., Ó. Talavera M., M. L. Sampedro R. y E. Hernández C. 2019. Caracterización morfológica de Agave angustifolia y su conservación en Guerrero, México. Revista Mexicana de Ciencias Agrícolas 10(3):655-668. Doi: 10.29312/remexca.v10i3.1554.

Baskin, C. C. and J. M. Baskin. 2001. Seeds. Ecology, Biogeography, and Evolution of dormancy and germination. Elsevier. Amsterdam, AMN, Netherlands. 666 p.

Calderón de Rzedowski, G. y M. T. Germán. 1993. Flora del Bajío y de Regiones Adyacentes. Fascículo 11. Familia Meliaceae. Instituto de Ecología, A. C. y Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (Conabio). Pátzcuaro, Mich., México. 28 p.

Constantino, M., R. Gómez-Álvarez, J. D. Álvarez-Solís, J. Pat-Fernández y G. Espín. 2010. Efecto de la biofertilización y los biorreguladores en la germinación y el crecimiento de Carica papaya L. Revista Colombiana de Biotecnología 12(2):103-115. https://dialnet.unirioja.es/servlet/articulo?codigo=3410768. (14 de septiembre de 2024).

Cruz-Cárdenas, C. I., L. X. Zelaya M., G. Sandoval C., S. de los Santos V., … y S. Ruiz R. 2021. Utilización de microorganismos para una agricultura sostenible en México: consideraciones y retos. Revista Mexicana de Ciencias Agrícolas 12(5):899-913. Doi: 10.29312/remexca.v12i5.2905.

Di Sacco, A., M. Way, P. León L., C. I. Suárez B. y J. V. Díaz R. 2020. Manual de recolección, procesamiento y almacenamiento de semillas de plantas silvestres. Royal Botanic Gardens e Instituto de Investigación de Recursos Biológicos Alexander von Humboldt. Kew, RT, England. 79 p.

Finch-Savage, W. E. and G. Leubner-Metzger. 2006. Seed dormancy and the control of germination. New Phytologist 171(3):501-523. Doi: 10.1111/j.1469-8137.2006.01787.x.

García-López, J. I., N. A. Ruiz-Torres, R. H. Lira-Saldívar, I. Vera-Reyes y B. Méndez-Argüello. 2016. Técnicas para evaluar germinación, vigor y calidad fisiológica de semillas sometidas a dosis de nanopartículas. In: Centro de Investigación en Química Aplicada (CIQA). 2º Mini Simposio-Taller Agronanotecnología. CIQA. Saltillo, Coah., México. pp. 129-140. http://ciqa.repositorioinstitucional.mx/jspui/handle/1025/334. (19 de marzo de 2024).

García M., A., M. de J. H. Ordóñez D. y M. Á. Briones S. 2004. Biodiversidad de Oaxaca. Instituto de Biología de la Universidad Nacional Autónoma de México, Fondo Oaxaqueño para la Conservación de la Naturaleza y World Wildlife Found. Coyoacán, D. F., México. 605 p.

García-Mendoza, A. J. 2010. Revisión taxonómica del complejo Agave potatorum Zucc. (Agavaceae): nuevos taxa y neotipificación. Acta Botánica Mexicana 91:71-93. Doi: 10.21829/abm91.2010.292.

García-Mendoza, A. J., I. S. Franco M. y D. Sandoval G. 2019. Cuatro especies nuevas de Agave (Asparagaceae, Agavoideae) del sur de México. Acta Botánica Mexicana 126:e1461. Doi: 10.21829/abm126.2019.1461.

Gentry, H. S. 1982. Agaves of Continental North America. University of Arizona Press. Tucson, AZ, United States of America. 670 p. https://books.google.com.pe/books?id=TdgUAQAAIAAJ. (28 de agosto de 2024).

Gutiérrez-Hernández, G. F., Y. D. Ortiz-Hernández, L. J. Corzo-Ríos y T. Aquino-Bolaños. 2020. Composición química y germinación de semillas de tobalá (Agave potatorum). Interciencia 45(5):223-228. https://www.redalyc.org/articulo.oa?id=33963402007. (12 de marzo de 2024).

Ho, T. D., A. Gomez-Cadenas, R. Zentella and J. Casaretto. 2003. Crosstalk between gibberellin and abscisic acid in cereal aleurone. Journal of plant growth Regulation 22:185-194. Doi: 10.1007/s00344-003-0026-7.

Kaya, M. D. and E. G. Kulan. 2020. Effective seed priming methods improving germination and emergence of sugar beet under low-temperature stress. Sugar Tech 22(6):1086-1091. Doi: 10.1007/s12355-020-00848-5.

Martínez-Ramírez, S., A. Trinidad-Santos, G. Bautista-Sánchez y E. C. Pedro-Santos. 2013. Crecimiento de plántulas de dos especies de mezcal en función del tipo de suelo y nivel de fertilización. Revista Fitotecnia Mexicana 36(4):387-393. Doi: 10.35196/rfm.2013.4.387.

Ortiz-Hernández, Y. D., G. F. Gutiérrez-Hernández, L. J. Corzo-Ríos, E. García-Ramírez and S. H. Martínez-Tomás. 2018. Varietal and germinative characterization of Agave potatorum (Asparagaceae) seeds with different origins. Botanical Sciences 96(4):628-639. Doi: 10.17129/botsci.1914.

Peña-Valdivia, C. B., A. B. Sánchez-Urdaneta, J. R. Aguirre R., C. Trejo, E. Cárdenas and A. Villegas M. 2006. Temperature and mechanical scarification on seed germination of "maguey" (Agave salmiana Otto ex Salm–Dyck). Seed Science and Technology 34(1):47-56. Doi: 10.15258/sst.2006.34.1.06.

Quiñones-Aguilar, E. E., A. C. Montoya-Martínez, G. Rincón-Enriquez, P. Lobit and L. López-Pérez. 2016. Effectiveness of native arbuscular mycorrhizal consortia on the growth of Agave inaequidens. Journal of Soil Science and Plant Nutrition 16(4):1052-1064. Doi: 10.4067/S0718-95162016005000077.

R Core Team. 2020. R: A language and environment for statistical computing (version 3.5.3). Vienna, W, Austria. R Foundation for Statistical Computing.

Ramírez T., H. M. 2010. Características bioquímico-fisiológicas de la germinación y desarrollo de plantas jóvenes de maguey (Agave) y su relación con la especie, temperatura y potencial de agua del sustrato. Tesis de Doctorado. Colegio de Postgraduados, Campus Montecillo. Texcoco, Edo. Méx., México. 160 p.

Ramírez T., H. M., R. Niño V., J. R. Aguirre R., J. Flores, J. A. De-Nova V. and R. Jarquín G. 2016. Seed viability and effect of temperature on germination of Agave angustifolia subsp. tequilana and A. mapisaga; two useful Agave species. Genetic Resources and Crop Evolution 63:881-888. Doi: 10.1007/s10722-015-0291-x.

Rao, N. K., J. Hanson, M. E. Dulloo, K. Ghosh, D. Novell y M. Larinde. 2007. Manual para el manejo de semillas en bancos de germoplasma. Bioversity International. Roma, RM, Italia. 165 p.

Torres, I., A. Casas, E. Vega, M. Martínez-Ramos and A. Delgado-Lemus. 2015. Population dynamics and sustainable management of Mescal Agaves in Central Mexico: Agave potatorum in the Tehuacán Cuicatlán Valley. Economic Botany 69:26-41. Doi: 10.1007/s12231-014-9295-2.

Trinidad-Cruz, J. R., E. E. Quiñones-Aguilar, L. V. Hernández-Cuevas, L. López-Pérez y G. Rincón-Enríquez. 2017. Hongos micorrízicos arbusculares asociados a la rizosfera de Agave cupreata en regiones mezcaleras del estado de Michoacán, México. Scientia Fungorum 45:13-25. Doi: 10.33885/sf.2017.0.1164.

Vázquez D., E., J. R. García N., C. B. Peña V., H. M. Ramírez T. y V. Morales R. 2011. Tamaño de semilla, emergencia y desarrollo de la plántula de maguey (Agave salmiana Otto ex Salm-Dyck). Revista Fitotecnia Mexicana 34(3):167-173. Doi: 10.35196/rfm.2011.3.167.

Vásquez, W., P. Pupiales, P. Viteri, A. Sotomayor, … y W. Viera. 2019. Escarificación química y aplicación de ácido giberélico para la germinación de semillas de cultivares de mora (Rubus glaucus Benth). Interciencia 44(3):161-166. https://www.redalyc.org/journal/339/33958848009/html/. (21 de marzo de 2024).

Todos los textos publicados por la Revista Mexicana de Ciencias Forestales –sin excepción– se distribuyen amparados bajo la licencia Creative Commons 4.0 Atribución-No Comercial (CC BY-NC 4.0 Internacional), que permite a terceros utilizar lo publicado siempre que mencionen la autoría del trabajo y a la primera publicación en esta revista.