Proceso morfogénico para la inducción de estructuras de novo, a partir de callos obtenidos de vitroplantas de Cinchona officinalis L., en condiciones de fotoperiodo y oscuridad

Cinchona officinalis L. is a native forest species of the Andes, emblematic of our country, with great medicinal, cultural and historical importance, whose populations have been threatened and exploited by different anthropogenic activities, for the use of its highly marketable alkaloids. The propagation of the species depends on the dispersal of the seeds and their germination capacity, therefore, the natural habitat of the Cinchona species in the province of Loja is being threatened in its natural habitat, making it necessary to investigate alternatives for the massive propagation and restoration in degraded ecosystems, so it is necessary to carry out research that provides alternative techniques for the propagation of the species, with plant tissue culture being a valid alternative to contribute to this aim. In this perspective, the current research was developed, whose purpose was to determine the adequate hormonal balance, for the induction phase of de novo shoots, from calluses of Cinchona officinalis L. The in vitro plant material was obtained from the germplasm bank generated in the research work carried out by Camacho (2023) under aseptic conditions in the Plant Micropropagation Laboratory of the UNL. For the de novo shoot induction phase, Cinchona officinalis L. calluses from vitroplants were inoculated in the Murashige and Skoog (MS) culture medium, supplemented with two cytokinins (benzyl amino purine and kinetin) in three concentrations (0.0; 2.0; 3.0 mg L -1), which were incubated under photoperiod conditions (16 hours of light and 8 hours of darkness) and total darkness. The variables evaluated in the formation of the de novo structures were: days to contamination, percentage of contamination, phenolization, survival, mortality, days to the formation of de novo structures; and, number and length of de novo structures. In this phase, a completely randomized experimental design was used, with 5 treatments and 3 repetitions per treatment. The results obtained showed that the contamination occurred exclusively under photoperiod conditions (16/8) in treatment 4, made up of 0.0 mg L -1 BAP + 3.0 mg L -1 KIN, reaching 6.67 % contamination; likewise, phenolic oxidation was higher under photoperiod conditions, where T3 (0.0 mg L -1 BAP + 2.0 mg L -1 KIN) presented 88 % oxidation of the explants; while, in conditions of total darkness, treatment T0 (0.0 mg L -1 BAP + 0.0 mg L -1 KIN) reached 27.50%, followed by T4 (0.0 mg L -1 BAP + 3.0 mg L -1 KIN) with 24% oxidation; therefore, in total darkness conditions in all evaluated treatments (T0, T1, T2, T3, T4), the maximum survival percentage (100 %) was reached. The results obtained determined that, under incubation conditions, with a photoperiod of 16 light hours and 8 dark hours, there was a direct relationship between phenolic oxidation, callus survival and de novo structures, since 5 as the oxidation level increased, causing the subsequent death of the inoculated callogenic structures in vitro. Regarding the variable average number of de novo roots, it began on day 21, reaching the highest average number in T0 with 11.77 de novo roots, under photoperiod conditions; however, under total darkness conditions T3 (0.0 mg L -1 BAP + 2.0 mg L -1 KIN) reached the highest average number with 14.97 de novo roots. The callogenic structures formed de novo roots, under photoperiod conditions they formed the highest percentage of 80 % in T0 (0.0 mg L -1 BAP + 0.0 mg L -1 KIN) and in a lower percentage under dark conditions, where T3 (2.0 mg L -1 BAP + 0.0 mg L -1 KIN) reached 70 %; and, it is necessary to emphasize, that the roots showed greater vitality in the treatments that did not contain any hormonal concentration. Regarding de novo root formation in the callogenic structures, the greatest average length occurred in the T0 treatment, both in photoperiod and dark conditions, with 0.16 and 0.17 mm respectively. Finally, it is necessary to point out that the control treatment consisting only of the mineral salts of the basal culture medium of Murashige and Skoog (MS-1962), without any level of cytokinins (0.0 mg L -1 BAP + 0.0 mg L -1 KIN), generated greater fresh mass of undifferentiated cells in the callogenic structures and stimulated the greatest number and length of de novo roots.

• 主要作者: Ramon Abad, Sayda Nidia (author)
• 格式: bachelorThesis
• 語言: spa
• 出版: 2023
• 主題: CINCHONA OFFICINALIS; MICROPROPAGACIÓN IN VITRO; BIOTECNOLOGÍA VEGETAL
• 在線閱讀: https://dspace.unl.edu.ec/jspui/handle/123456789/27886