In Vitro Culture of Coconut (Cocos nucifera L.) Zygotic Embryos

Abstract

Coconut is a very important crop for millions of people in tropical countries. With coconut, in vitro culture protocols have been developed with two main objectives, viz. the large scale production of particular types of coconuts and the international exchange and conservation of coconut germplasm. The methods described in this chapter have been developed in the framework of collaborative activities between research institutes in Côte d'Ivoire and France. Two coconut embryo in vitro collecting protocols have been established, one consisting of storing the disinfected embryos in a KCl solution until they are brought back to the laboratory, where they are re-disinfected and inoculated in vitro under sterile conditions, and the other including in vitro inoculation of the embryos in the field. For international germplasm exchange, zygotic embryos inoculated in vitro in plastic test tubes or endosperm cylinders containing embryos in plastic bags are used. For in vitro culture, embryos are inoculated on semi-solid medium supplemented with sucrose and activated charcoal and placed in the dark, and then transferred to light conditions with the same (solid or liquid) medium once the first true leaf is visible and the root system has started developing.

Embryonic dormancy in seeds of Bactris gasipaes Kunth (peach-palm)

“…In some species, such as Cocos nucifera Linn. it is even necessary to transfer the differentiated embryos to a fresh culture in order to achieve bud development (Engelmann et al, 2011). It is possible to affirm that seed dormancy is caused, in part, by embryonic dormancy because seeds with slow germination also exhibit slow embryonic differentiation (Figure 2), demonstrated by the significant correlation between the emergence speed index and the index of differentiation speed.…”

Effects of Surface Sterilization Protocol and Haustorium Removal on Germination and Growth of Hybrid PB121 Coconut Palm (Cocos nucifera L.) Zygotic Embryos Cultured in vitro

“…Similar results were obtained by Molla et al [23] on three coconut varieties after 6 months of culture. According to Engelmann et al [7] seedlings can be acclimatized when they display 3 to 4 unfolded green leaves and reach the acclimatization stage 6 to 7 months after initiation on MS basal medium. However, the use of Y3 medium combined with the suppression of haustorium resulted in acclimatized seedlings after five months of culture.…”

“…The multiplication of hybrid coconut genotypes (elite) at the Sèmè-Kpodji station of the National Agricultural Research Institute of Benin has led to requests for plants from countries such as Nigeria, Senegal, Niger and Lebanon. Unfortunately, exchange of germplasm is difficult because of the high risk of introducing pests and diseases between countries if whole nuts are exchanged, and also because of the high cost of transporting whole nuts [7,8]. To overcome this deficiency, protocols for the in vitro culture of zygotic embryos have been advanced in the developing countries.…”

Biotechnology and Conservation of Plant Biodiversity

“…Different protocols for in vitro collecting of coconut germplasm have been reported [14,[20][21][22]. One of the most recent protocols involves storing the disinfected embryos in a KCl solution until they arrive to the laboratory; then, they are re-disinfected and inoculated under sterile conditions on semi-solid medium supplemented with sucrose and activated charcoal, placing them in the dark and then transferring cultures to light conditions once the shoots and roots start to develop [23]. Other representative examples of in vitro collecting techniques are presented in Table 1.…”