Métodos de micropropagação de abacaxizeiro

Abstract

Resumo -O objetivo deste trabalho foi comparar diferentes métodos de micropropagação in vitro de abacaxizeiro em larga escala. Os tratamentos utilizados foram micropropagação convencional em meio sólido (5 e 6 g L -1 de ágar) e em meio líquido, e micropropagação em biorreator de imersão temporária -imersão no meio de cultura a cada 2, 4 e 8 horas, por 3 min -e contínua, com aeração a cada 2, 4 e 8 horas, por 3 min. Utilizou-se meio MS suplementado com 1 mg L -1 de BAP, 0,25 mg L -1 de ANA, pH ajustado para 5,8. As culturas foram mantidas em sala de crescimento com 25±1 o C, sob luz branca fria (40 µmol m -2 s -1 ), com 16 horas de fotoperíodo. O delineamento foi inteiramente casualizado, com nove tratamentos e quatro repetições. Depois de 45 dias de cultivo, foram avaliados número de brotos, brotações superiores a 1 cm, comprimento de brotos, massa de matéria fresca e massa de matéria seca de brotos. Sistemas de imersão temporária, com as plântulas imersas a cada 2 horas por 3 min, proporcionaram maior número, altura e massa de matéria seca de brotos de abacaxizeiro. O sistema de imersão temporária é o método mais eficiente na micropropagação de abacaxizeiro em larga escala.Termos para indexação: Ananas comosus, propagação vegetal, imersão temporária. Micropropagation methods of pineappleAbstract -The objective of this work was to compare different methods of pineapple in vitro mass micropropagation. The treatments were conventional micropropagation in solid medium (5 and 6 g L -1 agar) and in liquid medium, micropropagation in bioreactor of temporary immersion (immersion in culture medium each 2, 4 and 8 hours, for 3 minutes) and continuous immersion (with aeration each 2, 4 and 8 hours, for 3 minutes). MS medium supplement with 1 mg L -1 BAP, 0.25 mg L -1 NAA, and pH adjusted to 5.8 was utilized. Cultures were incubated at 25±1 o C under cool white fluorescent tubes (40 µmol m -2 s -1 ) with a 16-hours photoperiod. The experiment design was completely randomized, comprising nine treatments and four replicates. After 45 days, number of shootings, shootings higher than 1 cm, length of shootings, fresh matter of shootings and dry matter of shootings were evaluated. Temporary immersion system in each 2 hours for 3 minutes provided higher number, height and dry matter of pineapple shootings. Temporary immersion system is the most efficient method in pineapple mass micropropagation.

Utilization of the biorreactor of imersion by bubbles at the micropropagation of Ananas comosus L. Merril

“…The average number of leafs shoots did not show significant difference between the two systems of immersion. Silva et al (2007) reports that the system of immersion is more suitable to the explants growth in liquid cultivation. Other important aspects are the homogenization of the culture medium and the aeration time provided by the bioreactor.…”

“…The same system is being used at Asia, Europe, South and North America, to propagate plants with agronomical interest, mainly fruits, forestal and ornamental species. According to Rech Filho (2004) and Silva et al (2007) the cultivation in bioreactors systems can be divided into continuous and temporary. Teixeira (2002) reports that these equipments use liquid culture medium, they can renovate air during the cultivation and they allow the control of some essential parameters to the growth, such as pH, dissolved oxygen, temperature, ion concentration.…”

“…When it is required to increase production to large scale, the bioreactor systems are options to be considered, because they reduce the production costs of seedlings originated from somatic embryo, cells suspensions or whole organs (Silva et al, 2007). Many authors relate the success of cultivation when using bioreactors with species such as banana (Lemos et al, 2001), sugar-cane (Lorenzo et al, 1998), orquidea (Paek et al, 2001) and pineapple (Escalona et al, 1999;Guerra et al, 1999;Feuser et al, 2001;Silva et al, 2007). They report higher multiplication rates when compared with the traditional system.…”

Micropropagation of Agapanthus umbellatus var. minor by using two systems of multiplication

“…However, cloning involves periodic transferences of plant material to fresh medium, after subculture of four to six weeks. Currently, there is a tendency to use liquid medium in a temporary immersion system (SIT) for the fast growth of explants (LORENZO et al, 1998;ETIENNE;BERTHOULY, 2002;RODRIGUES et al, 2006;SILVA et al, 2007;NASCIMENTO et al, 2012).…”

“…Every 2 h, when light was pro the growth room, the liquid medium was pumped into the upper compartment for 1 min (SILVA 2007). An aquarium pump (Nevoni, São Paulo, Brazil) and a timer switch (Gubintec TI-12A, M Brazil) that controlled the frequency and duration of the immersion stage were used.…”