Cuban Journal of Forest Sciences. 2021; September-December 9(3): 412-422

Translated from the original in spanish

Influence of Cinchona officinalis (Rubiaceae) seedling size on survival and stem deformation after replanting

Influencia del tamaño de plántula de Cinchona officinalis (Rubiaceae) en la supervivencia y deformación del tallo posterior al repique

Efeito do tamanho das mudas de Cinchona officinalis (Rubiaceae) na sobrevivência pós-transplantio

Franklin Hitler Fernández Zarate^1* https://orcid.org/0000-0002-8203-9026

Annick Estefany Huaccha Castillo² https://orcid.org/0000-0002-9556-0080

Lenin Quiñones Huatangari¹ https://orcid.org/0000-0002-0953-328X

Tito Sánchez Santillán³ https://orcid.org/0000-0002-3352-341X

¹Institute of Data Science of the National University of Jaén. Perú.
²Professional School of Forestry and Environmental Engineering of the National University of Jaén. Perú.
³Research Institute of the Peruvian Amazon. Perú.

^*Corresponding author: fran.9615fernandez@gmail.com

Received: 22/06/2021.
Approved: 21/09/2021.

ABSTRACT

Cinchona officinalis, known as cinchona tree, is a species of high medicinal value that became popular for its antimalarial and febrifuge properties and is listed as an endangered species. The objective of this study was to determine the influence of C. officinalis seedling size on survival and steam deformation after pricking out. A completely randomized design was applied with three treatments according to seedling height; 1) from 2.0 to 5.0 cm, 2) from 5.1 to 8.0 cm and 3) greater than 8.1 cm. For each treatment, three replicates and ten seedlings (experimental unit) were used for each replicate. The lowest survival rate was recorded in group 3 (30.0 ± 10 %), while the highest survival rate was recorded in group 1 (86.7 ± 5.8 %). Regarding the effect of C. officinalis seedling size on the presence of steam deformation, group 1 had the lowest deformation (20.0 ± 10 %), while group 3 had the highest number of individuals with deformed steam (83.3 ± 15.3 %). It is concluded that the survival and morphological characteristics of C. officinalis at 60 days in the nursery are directly proportional to the size of the seedlings used during the replanting process.

Keywords: Cinchona officinalis; Replanting; Nursery forest.

RESUMEN

Cinchona officinalis L., conocida como árbol de la quina, es una especie de alto valor medicinal que se popularizó por su uso antimalárico, propiedades febrífugas y se encuentra catalogada como especie en peligro de extinción. El objetivo de este estudio fue determinar el efecto del tamaño de plántula de C. officinalis L. en la supervivencia y deformación del tallo posterior al trasplante. Se aplicó un diseño completamente al azar con tres tratamientos según la altura de la plántula; 1) de 2,0 a 5,0 cm, 2) de 5,1 a 8,0 cm y 3) mayor a 8,1 cm. Por cada tratamiento se empleó tres repeticiones y diez plántulas (unidad experimental) por cada repetición. Se registró la menor tasa de supervivencia en el grupo 3 (30,0 ± 10 %), mientras que la mayor tasa de supervivencia se registró en el grupo 1 (86,7 ± 5,8 %), en cuanto al efecto del tamaño de la plántula de C. officinalis L.sobre la presencia de deformaciones en el tallo el grupo 1 fue el que presentó la menor deformación (20,0 ± 10 %), mientras que el grupo 3 fue el que presentó el mayor número de individuos con el tallo deformado (83,3 ± 15,3 %). Se concluye que la supervivencia y características morfológicas de C. officinalis L. guardan una relación directamente proporcional al tamaño de las plántulas utilizadas en el trasplante.

Palabras clave: Cinchona officinalis; Trasplante; Vivero forestal.

RESUMO

Cinchona officinalis L., conhecida como árvore cinchona, é uma espécie de alto valor medicinal que se tornou popular por suas propriedades antipalúdicas, febrífugas e está listada como uma espécie ameaçada de extinção. O objetivo deste estudo era determinar o efeito do tamanho da muda de C. officinalis L. na sobrevivência e deformação do caule após o transplante. Um projeto completamente aleatório foi aplicado com três tratamentos de acordo com a altura das mudas; 1) 2,0 a 5,0 cm, 2) 5,1 a 8,0 cm e 3) maior que 8,1 cm. Para cada tratamento, foram utilizadas três réplicas e dez mudas (unidade experimental) por réplica. A menor taxa de sobrevivência foi registrada no grupo 3 (30,0 ± 10 %), enquanto a maior taxa de sobrevivência foi registrada no grupo 1 (86,7 ± 5,8 %). Com relação ao efeito do tamanho da muda de C. officinalis L. na presença de deformação do caule, o grupo 1 teve a menor deformação (20,0 ± 10 %), enquanto o grupo 3 teve o maior número de indivíduos com caules deformados (83,3 ± 15,3 %). Conclui-se que as características de sobrevivência e morfológicas de C. officinalis L. são diretamente proporcionais ao tamanho das plântulas utilizadas no transplante.

Palavras-chave: Cinchona officinalis; Transplante; Viveiro florestal.

INTRODUCTION

Peru is a mega diverse country due to the variety of flora and fauna species, ecosystems and its genetic and cultural resources (Fajardo et al., 2014). In the country, the presence of plants of medicinal and food importance stands out (De-la-Cruz et al., 2007). Such is the case of the genus Cinchona (C. officinalis L., C. pubescens Vahl, C. micrantha Ruiz and Pav.) whose bark contains quinine alkaloids (especially: quinine, quinidine, cinchonine and cinchonidine), which were used for more than three centuries as the only treatment against malaria (Loayza et al., 2010). Cinchona officinalis was exploited for centuries and its bark was exported to many parts of the world, the most conservative figures state that between the XVII and XVIII century approximately half a million kilograms of bark were exported to Europe per year (Roersch van der Hoogte and Pieters 2015), according to the last study conducted more than three decades ago, populations were stable, however, there is considerable pressure due to the expansion of the agricultural and logging frontier (Zevallos 1989).

Andean forests with Cinchona species presence have been subject to anthropogenic pressure over the last 350 years (López, 2016). The remaining trees of C. officinalis are restricted to scattered individuals located in fragmented habitats as a result of burning and urban expansion (Huamán et al., 2019). Therefore, it is important to understand aspects related to its propagation in order to generate management and conservation plans.

Among the methods used to reverse the depredation of an area is the installation of forest plantations (Ferez et al., 2015); this mechanism promotes a rapid recovery of the forest structure, generating a suitable habitat for the reestablishment of ecological succession (Holl and Aide 2011).

Various factors influence the development of seedlings during the nursery stage; within which are the availability of water, shade, nutrients, substrate, weeds, transplant age, pests and diseases (Poorter et al., 2012a). The effect of management practices in nurseries on the quality of seedlings has been studied in different forest species including Pinus palustris Mill (South et al., 2005), Acacia koa (Dumroese et al., 2011), these studies they focused on the growth of the seedlings, which were carried out in research stations.

One of the stages that ensures success in the production of forest seedlings and subsequent installation in the final field is the replstting, so it is necessary to know factors such as the height of the seedling, morphological and physiological characteristics of the species and damage to the root system to ensure the survival of seedlings (Calegari et al., 2011). The highest seedling mortality is usually observed in the first two months after replanting (Viani and Rodrigues 2007; Turchetto et al., 2016) this is associated with water stress, when the root system of the seedlings has not yet been restored which causes a partial closure of the stomata for a prolonged period (Taiz and Zeiger, 2008). Therefore, once individual seedlings overcome this stage, the chances of survival increase (Turchetto et al., 2016).

There are no studies describing the influence of C. officinalis seedling size on post-repipe survival, however, other types of botanical and ecological studies of this species have been developed (Zevallos 1989; Aymard 2019) this fact makes the research pioneering in the area.

Therefore, the present work seeks to determine the influence of C. officinalis seedling size on survival and trunk deformation after pricking out.

MATERIALS AND METHODS

Study area

The test was conducted from February 8 to April 8, 2021 in the community of La Cascarilla (UTM coordinates 732697.45 E, 9372588.42 S), province of Jaén, Peru, the area has an average elevation of 1 810 m. a.s.l., and corresponds to premontane rainforest (bhP) (Holdridge 1987). Annual precipitation is 1,730 mm, with a minimum temperature of 13.0 ^ºC and a maximum of 20.5 ^ºC (Figure 1).

Figure 1. - Location of the study area in the community of La Cascarilla, province of Jaén, Peru

Study species

Cinchona officinalis is a species with seed dispersal generally anemochorous; in the arboreal state it can reach a height of 11-15 m, with a cylindrical trunk, 30 to 40 cm in diameter; the branching is sympodial; with an irregular globular crown, its leaves are simple, opposite and decussate, measuring 8 to 26.8 cm long (not including the petiole) and 7 to 18 cm wide, flowers in the form of terminal panicles 20 to 25 cm long, slightly pubescent. Flowers hermaphrodite, actinomorphic; calyx gamosepalous, about 4 mm long, cylindrical, with 5 small lobes; corolla white-red, with fused petals, 1.5 cm long, fruit in the form of a dark brown capsule, ellipsoid in shape, 0.8 to 2.5 cm long and 0.4 to 0.8 cm wide, dehiscent (Zevallos 1989).

Plant material

Ninety seedlings of C. officinalis were selected from the almacigueras beds, with good vigor and phytosanitary quality, with an average age of five months; they were classified into three groups according to their size: 1) from 2.0 to 5.0 cm, 2) from 5.1 to 8.0 cm and 3) larger than 8.1 cm. The seedlings were carefully removed, avoiding damage to the root system; they were then placed in containers with clean water, where they remained for 30 minutes until planting.

In the nursery the seedlings were placed in polyethylene bags with a volume of 684.4 cm³ (7.5 cm in diameter and 15.5 cm in height); containing a substrate collected from the forest, whose physical-chemical characteristics were; texture: sandy loam, pH: 4.2 ± 0.1, EC: 0.5 ± 0.0 dS/m, P: 8.5 ± 2.5 mg/kg, total N: 0.3 ± 0.0 %, Ca: 1.2 ± 0.0 meq/100 g, K: 82.7 ± 1.7 mg/kg, Na: 0.4 ± 0.0 meq/100 g, Mg: 0.3 ± 0.0 meq/100 g.

During pruning, it was taken into account that solar radiation and temperature should be relatively medium or low, therefore, this activity was carried out in the afternoon to avoid dehydration and wilting; additionally, the leaves of the seedlings were cut at 50% of the total area to regulate their transpiration.

The seedlings remained in environments protected by a green raschel mesh (65% shade), 2 irrigations per day were applied with a nebulized system to maintain the relative humidity of the environment and avoid wilting of the seedlings. Cultural work in the nursery was constant during the entire study phase.

Experimental design

The experiment was set up under a complete randomized design with 3 treatments (groups), 3 replicates and 10 subsamples per replicate. The duration was 60 days (Table 1).

Table 1. - Classification of treatments according to C. officinalis seedling size

Data recording

Data recording had two phases, the first was daily (first week after pricking out), recording the number of live seedlings and deformed stems. The second phase consisted of a weekly evaluation, recording the same parameters described above, until the end of the research. The data were recorded in a field notebook and then transferred to the Excel digital template, in which survival was expressed as a percentage.

Data analysis

C. officinalis seedling survival data were subjected to analysis of variance (ANOVA) in order to determine the existence or not of significant statistical differences between treatments, then comparison of means was performed with Tukey's HSD post hoc test (P = 0.05). StatGraphics Centurion XVI software (StatPoint Technologies Inc, Warrenton, VA, USA) was used.

RESULTS

Figure 2A shows the cumulative survival rate expressed as a percentage of C. officinalis seedlings after replanting. The lowest survival rate was observed in group C (30.0 ± 10 %) whose stem height was greater than 8.1 cm, while the highest survival rate was recorded in group A (86.7 ± 5.8 %) which was comprised of seedlings between 2 and 5 cm in height. There were no significant differences between groups 1 and 2, but there were significant differences between groups 1 and 2 and test group 3. The mortality of C. officinalis seedlings is concentrated in the first six days after replanting; thereafter, no mortality of C. officinalis seedlings was recorded. The highest mortality rate was observed on the next day after replanting for all study groups, being higher in group 3 (4.3 ± 0.5 %) (Figure 2B).

Figure 2. - Effect of the size of different groups on the survival of C. officinalis seedlings (A) and daily mortality after repotting of dead C. officinalis seedlings (B).
Averages followed by different lowercase letters indicate significant differences between means according to a Tukey's post hoc test (P = 0.05)

Figure 3 shows the effect of C. officinalis seedling size on the presence of stem deformation in the seedling after replanting. Group 1 presented a lower incidence of stem deformation (20.0 ± 10 %), while group 3 seedlings presented a higher number of individuals with stem deformation (83.3 ± 15.3 %) (Figure 3).

Figure 3. - Effect of the size of the different groups on the stem deformation of C. officinalis seedlings.
Averages followed by different lowercase letters indicate significant differences between means according to a Tukey's post hoc test (P = 0.05).

DISCUSSION

The results of the study indicate a close relationship between seedling size and post repropagation survival and the presence of stem deformations. The mortality of C. officinalis seedlings was concentrated in the first seven days after replatting, this result is consistent with the results obtained by Viani and Rodrigues (2007). Seedling mortality is associated with the water stress that seedlings suffer after repotting when the root system has not yet recovered, generating a partial closure of the stomata, for a prolonged period causing chronic photoinhibition (Taiz and Zeiger 2008 ); consequently, when seedlings overcome this stage, the probability of survival increases (Turchetto et al., 2016).

When the seedlings are taken to the nursery, there are alterations in the microclimate, such as an increase in temperature, humidity and luminosity; such changes reduce the photosynthetic capacity of the plant by photoinhibition and degradation of photosynthetic pigments ( Kitaoet al., 2000 ), which causes a decrease in the efficiency of carboxylation and reduces the efficiency of photosystem II (Gilmore and Govindjee 1999). In this context, it is hypothesized that the percentage of seedling survival would increase if the replanting were carried out in periods with temperatures between 18 and 22 ^ºC, and that in the following months there are no extreme temperatures.

Factors such as seedling size, climatic conditions, physiological and morphological characteristics of the species, the time elapsed from the extraction of seedlings from the nursery to the pricking out and the damage caused to the root system, have a significant influence on the survival of seedlings after pricking out (Calegariet al., 2011).

The highest mortality and manifestation of stem deformation in C. officinalis seedlings was observed in the third group of trials (height > 1.5 m). officinalis seedlings was observed in the third test group (height > 8.1 cm). 8.1 cm), this would be related to the damage caused to the root system which generates a water imbalance in the seedling, losing more water than the roots can absorb (Lüttge 2008), in addition, the aerial biomass is greater in seedlings taller than 8. This generates a water imbalance since larger seedlings tend to be more demanding in water, so that mortality rates are higher when there is water stress (Turchetto et al., 2016).

CONCLUSION

C. officinalis seedlings at 60 days in the nursery survive and show their morphological characteristics in direct proportion to their size during pruning. Resulting, the smaller the size of the seedlings, the lesser the ditrimental effect caused by the edaphoclimatic conditions and the physiological behavior of the species. It is necessary to do more studies related to this subject, in order to find efficient methodologies that allow the mass production in nursery of this species with high medicinal value.

REFERENCES

AYMARD C., G.A., 2019. Breve reseña de los aspectos taxonómicos y nomenclaturales actuales del género Cinchona (Rubiaceae-Cinchoneae). Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales [en línea], vol. 43, no. 1, pp. 234-241. [Consulta: 30 junio 2021]. ISSN 0370-3908. DOI 10.18257/raccefyn.1079. Disponible en: http://www.scielo.org.co/scielo.php?script=sci_abstract&pid=S0370-39082019000500234&lng=en&nrm=iso&tlng=es.

CALEGARI, L., MARTINS, S.V., BUSATO, L.C., SILVA, E., COUTINHO JUNIOR, R. y GLERIANI, J.M., 2011. Produção de mudas de espécies arbóreas nativas em viveiro via resgate de plantas jovens. Revista Árvore [en línea], vol. 35, no. 1, pp. 41-50. [Consulta: 30 junio 2021]. ISSN 0100-6762 . DOI 10.1590/S0100-67622011000100005. Disponible en: https://www.scielo.br/j/rarv/a/TsXR8TZbjLN9bgHY34T4xmP/abstract/?lang=pt.

CRUZ, H. de la, VILCAPOMA, G. y POLLITO, P., 2007. Ethnobotanical study of medicinal plants used by the Andean people of Canta, Lima, Peru. Journal of Ethnopharmacology [en línea], vol. 111, no. 2, pp. 284-294. DOI 10.1016/j.jep.2006.11.018. Disponible en: https://www.researchgate.net/publication/266388116_Ethnobotanical_study_of_medicinal_plants_used_by_the_Andean_people_of_Canta_Lima_Peru.

DUMROESE, R. K., DAVIS, A. S. y JACOBS, D. F. 2011. Nursery response of Acacia koa seedlings to container size, irrigation method, and fertilization rate. Journal of Plant Nutrition [en línea], vol. 34, no. 6, pp. 877-887. [Consulta: 10 agosto 2021]. ISSN: 1532-4087. DOI 10.1080/01904167.2011.544356. Disponible en: https://www.tandfonline.com/doi/abs/10.1080/01904167.2011.544356

FAJARDO, J., LESSMANN, J., BONACCORSO, E., DEVENISH, C. y MUÑOZ, J. 2014. Combined use of systematic conservation planning, species distribution modelling, and connectivity analysis reveals severe conservation gaps in a megadiverse country (Peru). PLoS ONE [en línea], vol. 9, no. 12. [Consulta: 10 agosto 2021]. DOI 10.1371/journal.pone.0114367. Disponible en: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0114367.

FEREZ, A.P.C., CAMPOE, O.C., MENDES, J.C.T. y STAPE, J.L., 2015. Silvicultural opportunities for increasing carbon stock in restoration of Atlantic forests in Brazil. Forest Ecology and Management [en línea], vol. 350, pp. 40-45. [Consulta: 30 junio 2021]. ISSN 0378-1127. DOI 10.1016/j.foreco.2015.04.015. Disponible en: https://www.sciencedirect.com/science/article/pii/S0378112715002200.

GILMORE, A.M. y GOVINDJEE, 1999. How higher plants respond to excess light: energy dissipation in photosystem II. En: G.S. SINGHAL, G. RENGER, S.K. SOPORY, K.-D. IRRGANG, y GOVINDJEE (eds.), Concepts in Photobiology: Photosynthesis and Photomorphogenesis [en línea]. Dordrecht: Springer Netherlands, pp. 513-548. [Consulta: 30 junio 2021]. ISBN 978-94-011-4832-0. Disponible en: https://link.springer.com/chapter/10.1007/978-94-011-4832-0_16.

HOLDRIDGE, L.R., 1987. Ecología basada en zonas de vida [en línea]. San José, Costa Rica: Instituto Interamericano de Cooperación para la Agricultura (IICA). ISBN 978-92-9039-131-9. Disponible en: https://books.google.com.cu/books?id=m3Vm2TCjM_MC&printsec=frontcover#v=onepage&q&f=false.

HOLL, K.D. y AIDE, T.M., 2011. When and where to actively restore ecosystems? Forest Ecology and Management [en línea], vol. 261, no. 10, pp. 15-58-15-63. [Consulta: 30 junio 2021]. ISSN 0378-1127. DOI 10.1016/j.foreco.2010.07.004. Disponible en: https://www.sciencedirect.com/science/article/pii/S0378112710003750.

HOOGTE, A.R. van der y PIETERS, T., 2015. Science, industry and the colonial state: a shift from a German- to a Dutch-controlled cinchona and quinine cartel (18801920). History and Technology [en línea], vol. 31, no. 1, pp. 2-36. [Consulta: 30 junio 2021]. ISSN 0734-1512. DOI 10.1080/07341512.2015.1068005. Disponible en: https://www.tandfonline.com/doi/abs/10.1080/07341512.2015.1068005?journalCode=ghat20.

HUAMÁN, L., ALBÁN, J. y CHILQUILLO, E., 2019. Aspectos taxonómicos y avances en el conocimiento del estado actual del árbol de la Quina (Cinchona officinalis L.) en el Norte de Perú. Ecología Aplicada [en línea], vol. 18, no. 2, pp. 145-153. [Consulta: 30 junio 2021]. ISSN 1726-2216. DOI 10.21704/rea.v18i2.1333. Disponible en: http://www.scielo.org.pe/scielo.php?script=sci_abstract&pid=S1726-22162019000200005&lng=es&nrm=iso&tlng=es.

KITAO, M., LEI, T.T., KOIKE, T., TOBITA, H., MARUYAMA, Y., MATSUMOTO, Y. y ANG, L.-H., 2000. Temperature response and photoinhibition investigated by chlorophyll fluorescence measurements for four distinct species of dipterocarp trees. Physiologia Plantarum [en línea], vol. 109, no. 3, pp. 284-290. [Consulta: 30 junio 2021]. ISSN 1399-3054. DOI https://doi.org/10.1034/j.1399-3054.2000.100309.x. Disponible en: https://onlinelibrary.wiley.com/doi/abs/10.1034/j.1399-3054.2000.100309.x.

LOAYZA-O, K., DE OLIVEIRA, B.H., CÓNDOR, C.E. y REYNA, P.V. 2010. Estudio químico de los tallos de Cinchona pubescens. Revista de la Sociedad Química del Perú [en línea], vol. 7, no. 1, pp. 10-24. [Consulta: 10 agosto 2021]. ISSN 1810-634X. Disponible en: http://www.scielo.org.pe/pdf/rsqp/v75n1/a08v75n1.pdf

LOPEZ, N., 2016. Evaluación del paisaje y recursos escénicos después de 350 años de explotación de la "cascarilla" o "quina" Cinchona officinalis L. (Rubiaceae) en el sector Cajanuma-Rumishitana, Ecuador. Arnaldoa [en línea], vol. 23, no. 2, pp. 461-474. DOI 10.22497/arnaldoa.232.23205. Disponible en: https://www.researchgate.net/publication/311646129_Evaluacion_del_paisaje_y_recursos_escenicos_despues_de_350_anos_de_explotacion_de_la_cascarilla_o_quina_Cinchona_officinalis_L_Rubiaceae_en_el_sector_Cajanuma -Rumishitana_Ecuador.

LÜTTGE, U., 2008. Physiological Ecology of Tropical Plants [en línea]. 2. Berlin Heidelberg: Springer-Verlag. [Consulta: 30 junio 2021]. ISBN 978-3-540-71792-8. Disponible en: https://www.springer.com/gp/book/9783540717928.

POORTER, H., BÜHLER, J., VAN DUSSCHOTEN, D., CLIMENT, J. y POSTMA, J.A. 2012. Pot size matters: a meta-analysis of the effects of rooting volume on plant growth. Functional Plant Biology [en línea], vol. 39, no. 11, pp. 839-850. [Consulta: 10 agosto 2021]. ISSN: 1445-4408. DOI 10.1071/FP12049. Disponible en: https://www.publish.csiro.au/FP/fp12049

SOUTH, D.B., HARRIS, S.W., BARNETT, J.P., HAINDS, M.J., y GJERSTAD, D.H. 2005. Effect of container type and seedling size on survival and early height growth of Pinus palustris seedlings in Alabama, USA. Forest Ecology and Management [en línea], vol. 204, no. 2-3, pp. 385-398. [Consulta: 10 agosto 2021]. ISSN 0378-1127. DOI 10.1016/j.foreco.2004.09.016. Disponible en: https://www.sciencedirect.com/science/article/pii /S0378112704006929?casa_token=XwFj2Vxow2AAAAAA:uCHbMNqw9xBbw8aOPLvip8cvPPhGVxGHG25ddYCfBfVRPoEwQvA2Tw5nFkAOM0OydxF5Ve_dxldG

TAIZ, L. y ZEIGER, E., 2009. Fisiología vegetal. 4ta. Porto Alegre, Brasil: Artmed.

TURCHETTO, F., ARAUJO, M., TABALDI, L., GRIEBELER, A., RORATO, D., AIMI, S., BERGHETTI, A. y RODRIGUES GOMES, D., 2016. Can transplantation of forest seedlings be a strategy to enrich seedling production in plant nurseries? Forest Ecology and Management [en línea], vol. 375, pp. 96-104. DOI 10.1016/j.foreco.2016.05.029. Disponible en: https://www.researchgate.net/publication/303558807_Can_transplantation_of_forest_seedlings_be_a_strategy_to_enrich_seedling_production_in_plant_nurseries.

VIANI, R.A.G. y RODRIGUES, R.R., 2007. Sobrevivência em viveiro de mudas de espécies nativas retiradas da regeneração natural de remanescente florestal. Pesquisa Agropecuária Brasileira [en línea], vol. 42, no. 8, pp. 1067-1075. [Consulta: 30 junio 2021]. ISSN 0100-204X. DOI 10.1590/S0100-204X2007000800002. Disponible en: https://www.scielo.br/j/pab/a/BJXSGzFxTTMNbXLnDJDVm9j/abstract/?lang=pt.

ZEVALLOS POLLITO, P.A., 1989. Taxonomía, distribución geográfica y status del genero cinchona en el Perú. Agris [en línea], [Consulta: 23 marzo 2020]. Disponible en: http://agris.fao.org/agris-search/search.do?recordID=PE1989102947.

Conflict of interests:
The authors declare not to have any interest conflicts. 

Authors' contribution:
The authors have participated in the writing of the work and analysis of the documents.

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International license.
Copyright (c) 2021 Franklin Hitler Fernández Zarate, Annick Estefany Huaccha Castillo, Lenin Quiñones Huatangari, Tito Sánchez Santillán