Bioreactors in coffee micropropagation

Abstract

In coffee, bioreactors are the most promising way for scaling-up micropropagation processes, particularly somatic embryogenesis. The availability of an efficient somatic embryogenesis process would allow the rapid mass production of heterozygous materials such as selected Coffea canephora clones and F 1 Arabica hybrid varieties. For the last fifteen years, bioreactors (mechanically or pneumatically agitated bioreactors, temporary immersion bioreactors) have mostly been used on coffee to optimize the mass regeneration of somatic embryos from embryogenic tissues. This review presents the main results, obtained with several bioreactor models, concerning the different steps of the micropropagation process : i) the multiplication of embryogenic tissues, ii) the somatic embryo mass regeneration and iii) the production of pre-germinated embryos and plantlets in bioreactors. The literature shows that scaling-up can be successful, since very efficient embryo production has been achieved for both C. arabica and C. canephora. Moreover, it was proven that the pre-germinated coffee embryos -i.e. embryonic axis elongation (10-12 mm), root tip formation, cotyledon expansion and greening -obtained in temporary immersion bioreactors were photoautotrophic and able to regenerate vigorous plantlets after sowing under nursery conditions. The feasibility to apply the bioreactor technology in an industrial micropropagation procedure is also discussed in the particular socio−economic context of coffee growing.Key words: Coffea, breeding, liquid medium, mass propagation, somatic embryogenesis, temporary immersion.Bioreatores na micropropagação do café: Em café, o uso de bioreatores é a mais promissora maneira de aumentar o processo de micropropagação, particularmente a embriogênese somática. A disponibilidade de um eficiente processo de embriogênese somática poderia aumentar a rápida produção em massa de materiais heterozigotos, tais como clones selecionados de Coffea canephora clones e variedades híbridas F 1 de Coffea arabica. Nos últimos 15 anos, bioreatores (bioreatores mecanicamente ou pneumaticamente agitados, bioreatores de imersão temporária) têm sido predominantemente usados em café para otimizar a regeneração em massa de embriões somáticos, a partir de tecidos embriogênicos. Esta revisão apresenta os principais resultados obtidos com vários modelos de bioreatores, no que diz respeito aos vários passos do processo de micropropagação: i) a multiplicação de tecidos embriogênicos, ii) a regeneração em massa de embriões somáticos e iii) a produção de embriões pré-germinados e plântulas nos bioreatores. A literatura mostra que o escalonamento do processo de micropropagação pode ser útil, desde que uma produção muito eficiente de embriões seja atingida para C. arabica e C. canephora. Além disso, foi demonstrado que embriões pré-germinados de café -i.e. com alongamento do eixo embrionário (10-12 mm), formação de ponta de radícula, expansão do cotilédone e esverdeamento -obtidos em bioreatores de imersão temporária eram fotoautotrófico...

Large-scale, high-efficiency production of coffee somatic embryos

“…Etienne et al (2006) reported an average embryo size of 1.0-1.2 cm for a RITA with 800 cotyledonary embryos, a much smaller size than found for the RITAs in the present study with 500 embryos each.…”

The Science of Plant Tissue Culture as a Catalyst for Agricultural and Industrial Development in an Emerging Economy

“…The plants that develop in liquid media are fragile, have a glassy appearance, with succulent leaves or shoots and a poor root system [38] . Hyperhydricity in micropropagation has been reported in previous studies [39], [40] .…”

“…Several authors have reported the use of bioreactors for plants propagation [28] , [29] . To reduce the intensive labour requirement along with the production cost during plant propagation by tissue culture technique, there is an immense need of developing scale-up systems and automation [30] .…”

EFISIENSI MEDIA KULTUR DAN APLIKASI TEMPORARY IMMERSION SYSTEM PADA EMBRIOGENESIS SOMATIK KOPI ARABIKA / Efficiency of Culture Media and Aplication Temporary Immersion Systemon on Somatic Embryogenesis Arabica Coffee

“…(Etienne et al 2006). Penelitian penggunaan RITA ® juga dilaporkan lebih baik disbandingkan dengan media cair dan media semi padat pada tanaman Saccharum officinarum (Yang et al 2010) ; Eucalyptus Sp (McAlister et al 2005); Ananas comosus (pineapple) (Scheidt et al 2009).…”