Histological Analyses Reveal Promising Features in Coffea arabica Cell Suspension Culture

Abstract

Biotechnological techniques have been extensively studied to provide practical results for coffee improvement. Among these techniques, the present study deals with the somatic embryogenesis for crop improvement. Aims: To describe and correlate the morphology of Coffea arabica cell suspensions with their growth curve through electron microscopy and photonic analysis. Methodology: During 28 days of the culture period, samples of cell culture were collected at four days interval and the growth curve of the cell suspensions was performed by calculating the growth and the growth rate of the same. Cell suspension samples were used to perform the histological and ultrastructural analyses. Place and Duration of Study: The experiments were conducted at the Laboratório Central de Biologia Molecular (LCBM) and the Laboratório de Microscopia Eletrônica e Análise Ultraestrutural (LME) at the Federal University of Lavras, (Brazil), in the year 2017. Results: In the study period (28 days of culture), the growth curve of the cell suspensions exhibited sigmoid standard with four distinct phases: lag, exponential, linear and deceleration, represented by the regression equation y = -0,084x2 + 3,9399x + 2.85, significant at 5% probability. Histological and ultrastructural analyses allowed visualization of embryogenic characteristics in all the samples and with greater frequency in the samples that corresponded to time zero up to 20 days of culture. Conclusion: The importance of establishing the growth curve of cell suspensions is the identification of the phases in which the fundamental kinetic processes occur, allowing the correct manipulation of the same. Associated with this data, the identification of distinct types of cells allowed identification of the ideal cell suspension to obtain an efficient propagation system.