Sucrose concentration and blueberry plant density in temporary immersion systems (TIS)

The aim was to determine the ideal concentration of sucrose along with the number of plants per container in the face of micropropagation of blueberry under TIS. In the experiment conducted with sucrose concentration (0, 10, 20, e 30 g L-1), we utilized a WPM medium, taking into account 30 explants per container. For the experiment dealing with blueberry plant density, the same medium with 20 g L-1 of sucrose in conjunction with 30, 40, 50 and 60 explants per container was used. After 90 days from the installation of the trial, the following response variables were assessed herein: total length of the plant, number of shoots, length of the largest shoot, number of hyperhydric shoots, length of hyperhydric shoots, and number of healthy leaves. Under a sucrose concentration corresponding to 20 g L-1 the best possible results were obtained. Survival rates of 22 and 80% under the influence of both 10 and 20 g L-1 treatments were reported, pointing out that plants exposed to 20 g L-1 treatment were more amenable to acclimatization. Thus, for the micropropagation of blueberry under TIS the use of 20 g L-1 sucrose and 60 plants/container comes to being highly recommended to increase yield.

Propuesta de diseño y automatización de biorreactor para sistemas de inmersión temporal / Bioreactor Design and Automation Proposal for Temporary Immersion Systems

En este trabajo se presenta un prototipo de biorreactor como alternativa para la micropropagación de especies vegetales. Se trata de una propuesta que disminuye de manera significativa los costos tanto en la construcción del biorreactor como en la técnica de propagación. La automatización de varios de sus elementos de manera intrínseca supone la posibilidad de ser más eficiente en su operación, lo cual podrá permitir incrementar la producción masiva de propágulos de diferentes especies agrícolas. En la construcción de este nuevo sistema se utilizaron varios materiales: el uso de un contenedor para la sujeción de los elementos que participan en la inmersión, un motor a pasos, una plataforma que contendrá las plántulas, una placa electrónica Arduino Uno y una placa Raspberry Pi. Mediante la programación de la placa Arduino Uno, se automatiza el motor a pasos, el cual controla los movimientos de la plataforma de soporte que contiene los explantes. La construcción en general del sistema se logra por medio de materiales de fácil adquisición como plásticos y metales de bajo costo. Como resultado, se logró construir un nuevo biorreactor para la micropropagación masiva de especies vegetales de fácil manejo, gracias al cual se espera tener una mayor producción a corto plazo.

Sucrose concentration and volume of liquid medium on the in vitro growth and development of blackberry cv. Tupy in temporary immersion systems

ABSTRACT Micropropagation of small fruits such as blackberry has been employed due to the need to obtain plants with high phytosanitary quality. Bioreactor technology has been used to improve efficiency in seedling production. Thus, the objective of this work was to evaluate the best culture medium volume and sucrose concentration for blackberry micropropagation in a temporary immersion bioreactor. In vitro blackberry shoots were segmented containing two buds and an internode (1.0 cm) and placed into MS medium supplemented with inositol (0.1 g L-1), BAP (1 mg L-1) and sucrose (10, 20, 30 or 40 g L-1) at different medium volumes (150, 175 and 200 mL). The total length, number of leaves, number of shoots, and number of hyperhydric shoots were evaluated 56 days after start of the project. For blackberry development and propagation in a bioreactor system, the best results were shown at a medium volume of 175 ml and a sucrose concentration of 20 g L-1.

Temporary Immersion System for Micropropagation of Tree Species: a Bibliographic and Systematic Review

This paper was characterized by a bibliometric and systematic review on the database ISI Web of Science, aiming to provide an update of the main points addressed regarding the Temporary Immersion Systems (TIS) for micropropagation of tree species. It was pointed out that the frequency and time of immersion were one of the main parameters studied in the papers and 35% these papers worked with eucalyptus species. The main problem reported in the papers was the hyperhydricity, but it was overcome via procedures such as: a) air injection into the system, b) increasing the immersion intervals and decreasing the immersion time and c) decreasing concentration of cytokinin. Most papers reported that TIS produced plants that were more successful in surviving the ex-vitro acclimation stage than those produced on semi-solid media or continuous immersion systems. Few studies compared different types of temporary immersion bioreactors on micropropagation of plants and within the established criteria, papers with TIS tree species represented only 15% of the total. This system has presented promising results for most of the tree species, and although some gaps have been identified and few are the works with tree species, this process has been taking an increasingly larger space in the propagation of plants.

Promotion of Vegetative Growth in Force-ventilated Protea cynaroides L. Explants Cultured in Modified Temporary Immersion Culture Vessels

Temporary immersion culture vessels were modified to culture Protea cynaroides L. microshoots on semisolid growth medium. The effects of different ventilation treatments and sucrose concentrations on the vegetative growth and physiological characteristics of P. cynaroides L. microshoots were investigated. Three ventilation treatments were used: microshoots were either ventilated naturally or forced ventilated for 2 minutes/2 hours or 2 minutes/4 hours. In addition, two sucrose concentrations were used in the growth medium: 30 and 10 g·L−1. Significant interaction effects were found between ventilation and sucrose in the number of shoots formed. When cultured on growth medium with 10 g·L−1 sucrose, microshoots force-ventilated for 2 minutes/2 hours produced significantly higher number of shoots than those naturally ventilated or force-ventilated for 2 minutes/4 hours. In the 30 g·L−1 sucrose treatment, no significant differences in shoot numbers were observed among all ventilation treatments. The highest leaf areas were found in microshoots cultured in the 2 minutes/4 hours forced ventilation treatment, which were significantly higher than microshoots in the other ventilation treatments, irrespective of the sucrose concentration. Chlorophyll content was significantly higher in leaves of microshoots that were cultured in 30 g·L−1 sucrose compared with those grown in 10 g·L−1 sucrose in all ventilation treatments. Analysis of chlorophyll fluorescence of the leaves revealed that the Fv/Fm value of microshoots grown on 30 g·L−1 sucrose and force-ventilated for 2 minutes/4 hours was significantly higher than those naturally ventilated in the same sucrose treatment. Overall, the use of 30 g·L−1 sucrose in combination with 2 minutes/4 hours ventilation provided the best conditions for culturing P. cynaroides microshoots. This study demonstrated that these modified temporary immersion culture vessels can be used as a forced ventilation system to culture P. cynaroides microshoots and promote vegetative growth as well as improve their photosynthetic characteristics. The system described here introduces a simple and novel method of converting commercially available temporary immersion systems into force ventilation systems.