"Regeneración de plantas de café (coffea arabica cv. Caturra y catuaí) por embriogénesis somática directa a partir de segmentos de hoja"

Abstract

The main purpose of this investigation was to validate a system for in vitro embryo induction and regeneration using direct somatic embryogenesis from coffee leaf segments (Coffea arabica L. cv. Caturra and Catuaí) coming from vitroplants and three and twelve-month-old plants. Young leaves from greenhouse plants were treated with four sterilization procedures, in which four different concentrations of sodium hypochlorite (NaOCl) were tested. Different immersion times in an Agri-mycin and Benlate solution were also evaluated. For direct somatic embryogenesis induction, explants from apical and middle leaves of vitroplants were used. Explants from the distal, middle and basal parts of the three and twelve-month-old leaves were cultivated on the following culture media: CATIE embryo-induction (Flores y Abdelnour, 2000), Yasuda et al., 1985 modified by Bieysse et al.,1993 and Hatanaka et al., 1991. Somatic embryos in globular and torpedo stage of the Caturra variety were cultivated on the following embryo development media: CATIE, Yasuda et al., 1985 modified by Bieysse et al., 1993, Hatanaka et al., 1991 and the germination medium T5 (Solano, 2001). Concerning to the evaluated disinfections procedures, the method that required atomization with a bactericide (Agri-mycin) and fungicide (Benlate) solution, 60 minute immersion time of the explants in the bactericide-fungicide solution and 30 and 5 minutes immersion time in a solution of NaOCl 1.6 and 1% respectively resulted most effective for the control of contaminant microorganisms in the leaves from greenhouse coffee plants. The explants from Caturra and Catuaí vitroplants and three-month-old plants of the Caturra variety resulted best for direct somatic embryogenesis induction. The Yasuda et al., (1985) culture media modified by Bieysse et al., (1993) were the best for somatic embryogenesis induction. Histological studies allowed the detection of the process of direct somatic embryogenesis. The best germination percentage was obtained with the Yasuda et al., 1985 medium modified by Bieysse et al., 1993.