Effect of Different Procedures and Time Storage on the Contamination of Zygotic Embryos for the Purpose of Exchange of Coconut Germplasm

Southeast Asia is the main reference point as the center of origin and diversity of Coconut palm (Cocos nucifera L.), and its cultivation has spread to Latin America, Caribbean and Tropical Africa. Currently, coconut palm is grown in over 200 countries. The conservation and management of coconut genetic resources include target collecting, maintenance of field collections, characterization and identification, information management and effective and safe exchange germplasm. The aim of this study was to evaluate the effect of different procedures for packaging and storage time on the contamination of coconut zygotic embryos. The following treatments were applied to Cameroon Red Dwarf (CRD), Malayan Yellow Dwarf (MYD) and Malayan Red Dwarf (MRD) accessions; T1- endosperm disc storage at 10±2°C for 5 days; T2- endosperm disc storage at 10±2°C for 8 days; T3-  disc storage 10±2°C 1 for 12days (before de embryo excision and inoculation in the Y3 culture medium); T4- individual zygotic embryo inoculated in the Y3 culture medium and storage in the Eppendorf 5 mL and after 2 days transferred to Y3 cultured medium; T5-  five zygotic embryos inoculated in Y3 culture medium in the Petri dish and after 2 days transferred to Y3 culture medium. There wasn´t a significant effect of accessions (and treatments in the fungal contamination at 30 days after inoculation; however for the bacterial contamination was significant differences between accessions and treatments. The MDR accession showed higher bacterial contamination (27%) compared with CRD (11%) and MYD (5%) accessions. The zygotic embryos submitted to T4 presented less bacterial contamination (3.33%) compared with the others.