Development of synthetic seeds in Arabica coffee embryos under aseptic and non-aseptic conditions

In many tropical countries, Coffea arabica L. is a crop of great commercial and social importance. Synthetic seeds are an effective technique to propagate elite, hybrids, and genetically modified plant material. However, they are highly susceptible to microbial contamination when cultivated in non-aseptic conditions which results in limiting their applications. Here we aimed to evaluate different strategies under both aseptic and non-aseptic conditions to culture encapsulated coffee zygotic embryos with and without organic compounds (vitamins and sucrose). For both methods, encapsulated zygotic embryos were cultured in peat moss, soil with rice husk, and germination paper under greenhouse or plant growth culture room conditions. Growth room conditions resulted in better germination and capsules conservation compared with the greenhouse. The capsules with organic compounds cultivated in germination paper, under growth room conditions and previously sprayed with 1.5 mgl⁻¹ carbendazim, allowed better germination percentages (93%) after 1 month of culture. On the other hand, zygotic embryos encapsulated without organic compounds, under the same conditions, stopped their development and died with the course of the days until obtaining 100% of their mortality.