Asymbiotic germination of Vanilla planifolia in relation to the timing of seed collection and seed pretreatments.

We report a reliable protocol for seed pretreatment of mature seeds and for immature seeds culture based on a defined time schedule of V. plantifolia seed development. The window for successful germination of culturing immature seed was short. The quick accumulation of lignin, phenolics and/or phytomelanins in the seed coat may seriously inhibit seed germination after 45 DAP. As seeds matured, the thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, which may play an important role in inducing dormancy. Further studies covering different maturity of green capsules are required to understand the optimal seed maturity and germination of seeds.