Response of haustorium tissues and coconut water in somatic embryos induction for the coconut palm (Cocos nucifera L.) variety PB121

The coconut tree (Cocos nucifera L.)  is a fruit plant that contributes significantly to improved nutrition, food security, job creation, and household income in Benin. However, its production is suffering from the unavailability of certified seedlings. The present work aimed to optimize the propagation of coconut trees through the somatic embryogenesis technique. Zygotic embryos were cultured in vitro on Y3 medium supplemented with 0.7% Agar; 2.5 g/l activated charcoal, 5% sucrose to obtain haustorium, and the radicle explants for somatic embryogenesis. Three months after, callus and somatic embryos were induced from haustorium and radicle on medium Y3 supplemented with different doses of 2,4-D (0.3 and 0.35 mM) and coconut water (0, 50, 100 and 150 ml/l). 80% of callus was induced of induced with haustorium explant on Y3 medium supplemented with 0.7 mM 2,4-D.  The combination of 2,4-D and coconut water resulted in the highest average number of somatic embryos with 59 and 63 embryos obtained respectively on Y3 medium enriched with 150 ml/l coconut water and supplemented with 0.3 mM and 0.35 mM 2,4-D. Using haustorium explant for mass propagation through somatic embryogenesis remains an exploring way for in vitro seedling of coconuts.